3.1. Preliminary storage of structures in on-site warehouses is permitted only with appropriate justification. The on-site warehouse must be located within the range of the installation crane.

3.2. Installation of the structures of each overlying floor (tier) of a multi-story building should be carried out after the design fastening of all installation elements and the concrete (mortar) of the monolithic joints of load-bearing structures reaches the strength specified in the PPR.

3.3. In cases where the strength and stability of structures during the assembly process are ensured by welding installation connections, it is allowed, with appropriate instructions in the project, to install structures of several floors (tiers) of buildings without embedding the joints. In this case, the project must provide the necessary instructions on the procedure for installing structures, welding joints and grouting joints.

3.4. In cases where permanent connections do not ensure the stability of structures during their assembly, it is necessary to use temporary installation connections. The design and number of connections, as well as the procedure for their installation and removal, must be indicated in the PPR.

3.5. The brands of solutions used when installing bed structures must be indicated in the project. The mobility of the solution should be 5-7 cm along the immersion depth of a standard cone, except for cases specifically specified in the project.

3.6. The use of a solution whose setting process has already begun, as well as restoration of its plasticity by adding water, is not allowed.

3.7. Maximum deviations from alignment of landmarks when installing prefabricated elements, as well as deviations of completed installation structures from the design position should not exceed the values ​​​​given in table. 12.

Table 12

The designation adopted in table. 12: n - serial number of the tier of columns or the number of panels installed in height.

Note. The depth of support of horizontal elements on supporting structures must be no less than specified in the project.

INSTALLATION OF FOUNDATION BLOCKS AND WALLS OF THE UNDERGROUND PART OF BUILDINGS

3.8. The installation of glass-type foundation blocks and their elements in plan should be carried out relative to the alignment axes in two mutually perpendicular directions, combining the axial risks of the foundations with landmarks fixed to the base, or monitoring the correct installation with geodetic instruments.

3.9. The installation of strip foundation blocks and basement walls should be done, starting with the installation of lighthouse blocks in the corners of the building and at the intersection of the axes. Lighthouse blocks are installed by combining their axial marks with the marks of the alignment axes, in two mutually perpendicular directions. The installation of ordinary blocks should begin after checking the position of the lighthouse blocks in plan and height.

3.10. Foundation blocks should be installed on a layer of sand leveled to the design level. The maximum deviation of the leveling layer of sand from the design level should not exceed minus 15 mm.

Installation of foundation blocks on foundations covered with water or snow is not allowed.

Foundation glasses and supporting surfaces must be protected from contamination.

3.11. The installation of basement wall blocks should be carried out in compliance with the dressing. Row blocks should be installed with the bottom oriented along the edge of the blocks of the bottom row, and the top along the alignment axis. External wall blocks installed below ground level must be aligned along the inner side of the wall, and above - along the outer side. Vertical and horizontal seams between blocks must be filled with mortar and embroidered on both sides.

INSTALLATION OF COLUMNS AND FRAMES

3.12. The design position of columns and frames should be verified in two mutually perpendicular directions.

3.13. The bottom of the columns should be verified by combining the marks indicating their geometric axes in the lower section with the marks of the alignment axes or geometric axes of the columns below.

The method of supporting the columns on the bottom of the glass should ensure that the bottom of the column is secured from horizontal movement for the period before the unit is grouted.

3.14. The top of the columns of multi-story buildings should be verified by combining the geometric axes of the columns in the upper section with the marks of the alignment axes, and the columns of one-story buildings - by combining the geometric axes of the columns in the upper section with the geometric axes in the lower section.

3.15. Alignment of the bottom of the frames in the longitudinal and transverse directions should be done by combining the marks of the geometric axes with the marks of the alignment axes or axes of the racks in the upper section of the underlying frame.

Alignment of the top of the frames should be done: from the plane of the frames - by combining the marks of the axes of the frame posts in the upper section relative to the alignment axes, in the plane of the frames - by observing the marks of the supporting surfaces of the frame posts.

3.16. The use of gaskets not provided for in the design at the joints of columns and frame posts to level elevations and bring them into a vertical position without agreement with the design organization is not permitted.

3.17. Guidelines for aligning the top and bottom of columns and frames must be indicated in the PPR.

INSTALLATION OF BEAMS, BEAMS, TRUSSES, FLOOR PLATES AND COVERINGS

3.18. The laying of elements in the direction of the overlapped span must be carried out in compliance with the dimensions established by the design for the depth of their support on the supporting structures or the gaps between the mating elements.

3.19. Installation of elements in the transverse direction of the overlapped span should be carried out:

crossbars and intercolumn (tie) slabs - combining the risks of the longitudinal axes of the elements being installed with the risks of the axes of the columns on the supports;

crane beams - combining the risks that fix the geometric axes of the upper chords of the beams with the alignment axis;

sub-rafter and rafter trusses (beams) when supported on columns, as well as rafter trusses when supported on sub-rafter trusses - combining the risks fixing the geometric axes of the lower chords of the trusses (beams) with the risks of the column axes in the upper section or with the reference marks in the supporting unit of the truss farms;

rafter trusses (beams) resting on walls - combining the risks that fix the geometric axes of the lower chords of the trusses (beams) with the risks of the alignment axes on the supports.

In all cases, trusses (beams) should be installed in compliance with the one-sided direction of deviations from straightness of their upper chords:

floor slabs - according to markings that determine their design position on the supports and are carried out after installation of the structures on which they rest (beams, crossbars, trusses, etc.) in the design position;

covering slabs along trusses (rafter beams) - symmetrically relative to the centers of truss nodes (embedded products) along their upper chords.

3.20. Crossbars, intercolumn (tie) slabs, trusses (rafter beams), covering slabs along trusses (beams) are laid dry on the supporting surfaces of load-bearing structures.

3.21. Floor slabs must be laid on a layer of mortar no more than 20 mm thick, aligning the surfaces of adjacent slabs along the seam on the ceiling side.

3.22. The use of shims not provided for in the design to align the position of laid elements according to marks without agreement with the design organization is not permitted.

3.23. Alignment of crane beams in height should be done at the highest level in the span or on the support using spacers made of steel sheets. If a pack of gaskets is used, they must be welded together, the pack welded to the support plate.

3.24. Installation of trusses and rafter beams in a vertical plane should be performed by aligning their geometric axes on the supports relative to the vertical.

INSTALLING WALL PANELS

3.25. The installation of panels of external and internal walls should be carried out by resting them on beacons aligned with the installation horizon. The strength of the material from which the beacons are made should not be higher than the compressive strength of the mortar used to construct the bed established by the design.

Deviations of beacon marks relative to the installation horizon should not exceed ±5 mm. If there are no special instructions in the project, the thickness of the beacons should be 10-30 mm. There should be no gaps between the end of the panel after its alignment and the mortar bed.

3.26. Alignment of single-row cut external wall panels should be done:

in the plane of the wall - combining the axial mark of the panel at the bottom level with the reference mark on the ceiling, removed from the alignment axis. If there are zones for compensation of accumulated errors in the joints of panels (when joining panels overlapping in places where loggias, bay windows and other protruding or sinking parts of the building are installed), alignment can be done using templates that fix the design size of the seam between the panels;

from the plane of the wall - combining the lower edge of the panel with the installation marks on the ceiling, located from the alignment axes;

in the vertical plane - aligning the inner edge of the panel relative to the vertical.

3.27. Installation of belt panels of external walls of frame buildings should be carried out:

in the plane of the wall - symmetrically relative to the axis of the span between the columns by aligning the distances between the ends of the panel and the marks of the column axes at the level of the panel installation;

from the plane of the wall: at the level of the bottom of the panel - aligning the lower inner edge of the installed panel with the edge of the underlying panel; at the level of the top of the panel - combining (using a template) the edge of the panel with the axis mark or the edge of the column;

3.28. Alignment of wall panels of external walls of frame buildings should be done:

in the plane of the wall - combining the mark of the bottom axis of the installed panel with the reference mark marked on the waist panel;

from the plane of the wall - aligning the inner edge of the installed panel with the edge of the underlying panel;

in the vertical plane - aligning the inner and end edges of the panel relative to the vertical.

INSTALLATION OF VENTILATION UNITS, VOLUMETRIC UNITS OF ELEVATOR SHAFT AND SANITARY CABINS

3.29. When installing ventilation units, it is necessary to ensure that the channels are aligned and the horizontal joints are carefully filled with mortar. Alignment of ventilation units should be performed by aligning the axes of two mutually perpendicular faces of the installed units at the level of the lower section with the marks of the axes of the lower unit. The blocks should be installed relative to the vertical plane, aligning the planes of two mutually perpendicular faces. The joints of the ventilation ducts of the blocks should be thoroughly cleaned of the solution and prevent it and other foreign objects from getting into the ducts.

3.30. Volumetric blocks of elevator shafts should be mounted, as a rule, with brackets installed in them to secure guide cabins and counterweights. The bottom of volumetric blocks must be installed along the reference marks placed on the floor from the alignment axes and corresponding to the design position of two mutually perpendicular walls of the block (front and one of the side). The blocks should be installed relative to the vertical plane, aligning the edges of two mutually perpendicular walls of the block.

3.31. Sanitary cabins must be installed on gaskets. The bottom and verticality of the cabins should be adjusted according to clause 3.30. When installing cabins, the sewer and water risers must be carefully combined with the corresponding risers of the cabins below. The holes in the floor panels for the passage of cabin risers must be carefully sealed with mortar after installing the cabins, installing the risers and carrying out hydraulic tests.

CONSTRUCTION OF BUILDINGS BY METHOD OF LIFTING FLOORS

3.32. Before lifting floor slabs, it is necessary to check the presence of design gaps between the columns and slab collars, between the slabs and the walls of the stiffening cores, as well as the cleanliness of the design holes for lifting rods.

3.33. Lifting of floor slabs should be done after the concrete reaches the strength specified in the design.

3.34. The equipment used must ensure uniform lifting of floor slabs relative to all columns and stiffening cores. The deviation of the marks of individual support points on the columns during the lifting process should not exceed 0.003 spans and should not exceed 20 mm, unless other values ​​are provided for in the project.

3.35. Temporary fixation of slabs to columns and stiffeners should be checked at each stage of lifting.

3.36. Structures raised to the design level should be secured with permanent fastenings; in this case, intermediate acceptance certificates for completed structures must be drawn up.

WELDING AND ANTI-CORROSION COATING OF EMBODIED AND CONNECTING PRODUCTS

3.37. Welding of embedded parts and connecting products must be carried out in accordance with Section. 8.

3.38. Anti-corrosion coating of welded joints, as well as areas of embedded parts and connections, should be carried out in all places where the factory coating was damaged during installation and welding. The method of anti-corrosion protection and the thickness of the applied layer must be specified in the project.

3.39. Immediately before applying anti-corrosion coatings, the protected surfaces of embedded products, ties and welded joints must be cleaned of welding slag residues, metal splashes, grease and other contaminants.

3.40. During the application of anti-corrosion coatings, special care must be taken to ensure that protective layer corners and sharp edges of the products were covered.

3.41. The quality of anti-corrosion coatings must be checked in accordance with the requirements of SNiP 3.04.03-85.

3.42. Data on the anti-corrosion protection of connections performed must be documented in inspection reports hidden work.

FILLING JOINTS AND SEAMS

3.43. Embedding of joints should be carried out after checking the correct installation of structures, acceptance of connections of elements in mating units and anti-corrosion coating of welded joints and damaged areas of the coating of embedded products.

3.44. The class of concrete and brand of mortar for grouting joints and seams must be indicated in the project.

3.45. Concrete mixtures used for grouting joints must meet the requirements of GOST 7473-85.

3.46. To prepare concrete mixtures, quick-hardening Portland cements or Portland cements M400 and higher should be used. In order to intensify hardening concrete mixture In joints it is necessary to use chemical additives - hardening accelerators. The largest grain size of coarse aggregate in the concrete mixture should not exceed 1/3 of the smallest cross-sectional size of the joint and 3/4 of the smallest clear distance between the reinforcement bars. To improve workability, plasticizing additives should be added to the mixture in accordance with Section. 2.

3.47. Formwork for embedding joints and seams, as a rule, must be inventory and meet the requirements of GOST 23478-79.

3.48. Immediately before embedding joints and seams, it is necessary to: check the correctness and reliability of the installation of the formwork used for embedding; Clean the joining surfaces from debris and dirt.

3.49. When grouting joints, compaction of concrete (mortar), its care, control of the curing regime, as well as quality control should be carried out in accordance with the requirements of Section. 2.

3.50. The strength of the concrete or mortar in the joints at the time of stripping must correspond to that specified in the design, and in the absence of such instructions, it must be at least 50% of the design compressive strength.

3.51. The actual strength of the laid concrete (mortar) should be monitored by testing a series of samples made at the grouting site. To check the strength, at least three samples should be made per group of joints concreted during a given shift.

Testing of samples must be carried out in accordance with GOST 10180-78 and GOST 5802-86.

3.52. Methods of pre-heating of abutting surfaces and heating of cemented joints and seams, duration and temperature and humidity conditions of curing concrete (mortar), methods of insulation, timing and procedure for stripping and loading structures, taking into account the peculiarities of performing work in winter conditions, as well as in hot and dry weather must be indicated in the PPR.

WATER, AIR AND THERMAL INSULATION OF JOINTS OF EXTERNAL WALLS OF FULLY PREFABRICATED BUILDINGS

3.53. Work on insulating joints must be carried out by specially trained workers who have a certificate for the right to carry out such work.

3.54. Materials for insulating joints should be used only from those specified in the project; replacement of materials without agreement with the design organization is not allowed.

3.55. Transportation, storage and use of insulating materials should be carried out in accordance with the requirements of standards or technical specifications.

Insulating materials, after the expiration of the storage period established by standards or technical conditions, are subject to control testing in the laboratory before use.

3.56. Panels must be delivered to sites with primed surfaces forming joints. The primer should form a continuous film.

3.57. The surfaces of external wall panels forming joints must be cleaned of dust, dirt, concrete deposits and dried before performing water and air insulation work.

Surface damage to concrete panels at the joints (cracks, cavities, chips) must be repaired using polymer cement compositions. The damaged primer layer must be restored under construction conditions.

Application of sealing mastics to wet, frosty or icy joint surfaces is not permitted.

3.58. For air insulation of joints, air-protective tapes are used, fixed with adhesives or self-adhesive. It is necessary to connect air-protective tapes along the length with an overlap with a length of the overlap section of 100-120 mm. The connection points of the tapes in the wells of the vertical joints must be located at a distance of at least 0.3 m from the intersection of the vertical and horizontal joints. In this case, the end of the underlying tape should be glued over the tape installed at the joint of the floor being assembled.

It is not allowed to connect the tapes in height before the wells are sealed at the joints of the floor below.

3.59. The glued air-protective tape should fit snugly to the insulated surface of the joints without bubbles, swelling or folds.

3.60. Thermal insulation liners should be installed in the wells of vertical joints of external wall panels after installing air insulation.

Liner materials must have a moisture content specified in the standards or specifications for these materials.

3.61. The installed liners must fit tightly to the surface of the well along the entire height of the joint and be secured in accordance with the design.

There should be no gaps at the joints of thermal insulation liners. When eliminating gaps between the liners, they must be filled with material of the same volumetric mass.

3.62. Sealing gaskets at the mouths of closed and drained joints should be installed dry (without coating with glue). Where closed joints intersect, sealing gaskets should first be installed in horizontal joints.

3.63. In closed type joints when connecting external wall panels with an overlap, in drained horizontal joints (in the area of ​​the drainage apron), in horizontal joints open type, as well as at the joints of tongue-and-groove panels, it is allowed to install sealing gaskets before installing the panels. In this case, the gaskets must be secured in the designed position. In other cases, the installation of sealing gaskets must be done after installing the panels.

Nailing sealing gaskets to the surfaces forming the butt joints of external wall panels is not allowed.

3.64. Sealing gaskets should be installed in joints without breaks.

It is necessary to connect the sealing gaskets along the length “on the mustache”, placing the connection point at a distance of at least 0.3 m from the intersection of the vertical and horizontal joints.

It is not allowed to seal joints with two gaskets twisted together.

3.65. The compression of gaskets installed at joints must be at least 20% of the diameter (width) of their cross section.

3.66. Insulation of joints with mastics should be done after installing sealing gaskets by injecting mastics into the mouth of the joint using electric sealants, pneumatic, manual syringes and other means.

When performing repair work, it is allowed to apply curing mastics with spatulas. Liquefaction of mastics and application with brushes is not allowed.

3.67. When preparing two-component curing mastics, it is not allowed to violate the passport dosage and disassemble their components, mix the components manually and add solvents to them.

3.68. The temperature of mastics at the time of application at positive outside temperatures should be 15-20°C. During winter periods, the temperature at which the mastic is applied, as well as the temperature of the mastic at the time of application, must correspond to those specified in the technical specifications of the mastic manufacturer. In the absence of appropriate instructions in the technical specifications, the temperature of mastics at the time of application should be: for non-hardening - 35-40 ° C, for hardening - 15-20 ° C.

3.69. The applied layer of mastic must fill the entire mouth of the joint without voids up to the elastic gasket, and have no breaks or sagging.

The thickness of the applied mastic layer must correspond to that established by the project. The maximum deviation of the thickness of the mastic layer from the design one should not exceed plus 2 mm.

The resistance of applied mastics to separation from the panel surface must correspond to the indicators given in the relevant standards or technical specifications for the mastic.

3.70. Protection of the applied layer non-hardening mastic must be made with the materials specified in the project. In the absence of special instructions in the project, polymer cement solutions, PVC, butadiene styrene or coumaron rubber paints can be used for protection.

3.71. In open joints, rigid waterproof screens should be inserted into the vertical channels of open joints from top to bottom until they stop at the drainage apron.

When using rigid waterproof screens in the form of corrugated metal strips, they should be installed in vertical joints so that the opening of the outer corrugations faces the facade. The screen should fit into the groove freely. When the vertical joint of panels is opened more than 20 mm, two tapes should be installed, riveted at the edges.

Flexible waterproof screens (tapes) are installed in vertical joints both outside and inside the building.

3.72. Non-metallic drainage aprons made of elastic materials should be glued to the upper edges of the panels being joined for a length of at least 100 mm on both sides of the axis of the vertical joint.

3.73. Insulation of joints between window (balcony door) blocks and quarters in openings of enclosing structures should be done by applying non-hardening mastic to the surface of the quarter before installing the block or by injecting mastic into the gap between window blocks and enclosing structures after securing the block in the design position. The junction of metal window sill drains to the frame should also be insulated with non-hardening mastic.

When insulating joints between window blocks and enclosing structures with openings without a quarter, a sealing gasket should be installed before applying mastics.

3.74. The performance of work on insulating joints must be recorded daily in a log.

For the entire range of work on installing joint insulation, inspection reports for hidden work should be drawn up in accordance with SNiP 3.01.01-85.

The topic of this article is reinforced concrete load-bearing and enclosing structures. We have to understand their classifications and get acquainted with the requirements for installation work set out in the current regulatory documents.

Classification

What types of reinforced concrete structures are used in construction?

• Monolithic. The most obvious example is modern frame-monolithic apartment buildings. The supporting frame of the building is cast on site in removable formwork; After the concrete has gained strength, enclosing walls and partitions are erected from light porous materials.
• Prefabricated. An example of such a design is panel house: it is built from ready-made elements. Installation of prefabricated reinforced concrete structures, as a rule, comes down to combining the frame reinforcing the structural elements by welding and concreting the seams.

Useful: this technology, among other things, allows the use of structural elements with prestressed reinforcement. Reinforcing rods heated by high currents, when cooled, are stretched and thereby increase the bending strength of the product. The method of producing reinforced concrete with reinforced tension implies industrial conditions.

• Prefabricated - monolithic. This type of structure includes, for example, a floor made of slabs laid on monolithic crossbars.

In addition, during the construction of buildings and industrial facilities, dissimilar elements can be combined into a single structure. Joint installation of reinforced concrete and steel structures used, for example, when creating open warehouses adjacent to a building: beams or canopy trusses are welded to embedded parts in concrete or anchored to a monolith.

Regulations

What documents regulate the installation of reinforced concrete products?

We have to familiarize ourselves primarily with the contents of the last document: it contains the most complete information on installation work.

SNiP 3.03.01-87

The document applies to the following list of works:

• Construction of monolithic concrete and reinforced concrete walls, beams, columns, ceilings and other load-bearing and enclosing structures.

• Installation of prefabricated reinforced concrete and metal structures on a construction site.
• Welding of installation connections metal structures, welding of connections of reinforcement of reinforced concrete products and embedded parts in them.
• Construction from stone, ceramic, silicate and concrete blocks.

The work begins with drawing up a work plan (work plan). The project, among other things, must include a statement of the order of basic operations, taking into account the safety and manufacturability of construction.

All materials used must comply with applicable standards and/or specifications.

Let's study the basic requirements of SNiP.

Warehousing and moving

When storing, structural elements must be supported by rectangular gaskets with a thickness of at least 30 millimeters. For multi-tier storage, the spacers should be located on the same vertical line.

The valve outlets are protected from damage. Surfaces with a texture to ensure better adhesion to concrete also require protection.

Storage is carried out taking into account the installation order. In this case, the factory markings must remain visible.

Metal fasteners (bolts, nuts, etc.) are stored exclusively in indoors; they must be sorted by size, strength class, and in the case of high-strength products - by batch.

Dragging any products is prohibited. Lifting equipment is used to move or deliver to the work site. Slinging is carried out using the mounting loops or in the places indicated in the working drawings.

Let us clarify: ENiR for installation and construction work (a document containing uniform standards and prices) is based on moving cargo weighing up to 50 kg over a distance of up to 30 meters with your own hands, without the use of loading equipment.

The slinging method must prevent the slings from shifting and damaging the reinforcement. It is prohibited to rig products beyond the fittings. The position of the element during lifting should be as close as possible to the design one (that is, for example, a wall panel is delivered to the work site in a vertical position, and a floor panel in a horizontal position).

Elements rise without jerking or swinging; the required orientation in space is achieved by using guy wires (one for vertically oriented elements and at least two for horizontal parts of the structure).

The lifting is performed in two steps:

1. The product is raised by 20-30 cm to check the quality of the sling.
2. After checking, further ascent is carried out.

The method of fixing the elements must prevent their displacement at any stage of installation. Until it is securely fixed (permanent or temporary), the product cannot be used as a support for other structural elements.

Concrete works

According to SNiP, mixtures prepared in accordance with the following requirements:

Dosing of concrete components is carried out by weight. Only modifying additives (plasticizers, antifreeze, etc.) can be dosed according to the volume of mixing water.

The ratio of components is determined separately for each batch of cement and aggregate with mandatory control of samples for mobility and strength.

It is prohibited to increase the mobility of concrete by introducing water into it.

Before concreting, the surfaces of working joints must be cleaned of dirt, dust, debris, grease and oil stains, cement film, snow and ice. Immediately before laying concrete, the surface is washed with water and dried with a stream of air. The instruction is related to a decrease in the adhesion of cement to the base when the surface is contaminated.

Concrete is laid in horizontal layers of equal thickness.

When vibrating, the vibrator should not rest on reinforcement, embedded parts or formwork. The deep vibrator should be immersed 5-10 cm into the previously laid layer and move in increments of no more than one and a half radii of action; the surface one moves with a 10-centimeter overlap of the vibrated area.

Laying the next layer of concrete is permissible either before the previous layer has set, or after it has gained strength of at least 1.5 MPa. The same strength is necessary so that concrete can be walked on or the formwork of the overlying part of the structure can be installed.

Concrete processing

It may include cutting expansion joints, openings and technological holes.

• For all work, SNiP provides for the use of diamond tools. It is quite natural: despite the fact that its price is quite high, cutting reinforced concrete with diamond wheels is cheaper than the same work done with conventional abrasives. The reason is the huge difference in wear rate.

Useful: in addition, diamond drilling of holes in concrete, in contrast to the use of Pobedit drills and crowns, makes the edges of the hole perfectly smooth.

• The tool is cooled with water with the addition of surfactants, which reduce energy losses to overcome friction.
• The strength of concrete at the time of processing must reach at least 50% of the design strength.

Reinforcement

Weldless connections of reinforcing bars are made using annealed binding wire. For butt connections, the use of crimp sleeves and screw couplings is allowed.

It is preferable to use large-block reinforcing products or factory-made meshes.

When installing reinforcement, it is necessary to maintain the thickness of the protective layer of concrete to prevent contact of the reinforcement with atmospheric air and water.

Prefabricated structures

How does the document regulate the installation of prefabricated concrete and reinforced concrete structures?

• In the general case, the next tier of a multi-tiered structure is erected not only after connecting the reinforcing frames by welding, but also after sealing the seams and gaining concrete strength specified in the PPR. Exceptions are specifically stated in the draft.

• Temporary mounting ties can be used to secure the structural element during assembly. Their quantity, type and order of application are again specified in the PPR.
• For concreting joints, it is not allowed to use mortar that has begun to set. The consequence of violating this rule is a catastrophic drop in the compressive strength of the assembly seam.
• Crossbars, load-bearing trusses, intercolumn slabs and rafter beams are laid dry on the supporting surfaces of the columns, without mortar. Floor slabs are laid on the mortar; in this case, the thickness of its layer should not exceed 20 mm. The surfaces of adjacent slabs are leveled from the ceiling side.
• When installing ventilation units, you should monitor the filling of horizontal joints with mortar. There should be no gaps left.
• Plumbing cabins are placed on spacers aligning the vertical axis of the risers. The holes for risers are sealed after pressure testing of hot and cold water supply systems.

• For grouting the seams of prefabricated reinforced concrete structures, concrete based on quick-hardening Portland cement (grade M400 and higher) is used. The use of hardening accelerators is allowed and even recommended. Maximum size aggregate grains in concrete should not exceed 1/3 of the minimum cross-section of the joint and 3/4 minimum distance between reinforcement elements.
• At the time of removing the formwork, the concrete must reach the minimum strength specified in the design.

Please note: unless otherwise specified, formwork is removed after reaching 50% of the nominal strength.

• During installation of welded steel structural elements, shock impacts on them at low temperatures are prohibited. To be precise, for steels with a yield strength of 390 MPa or less, the lower temperature limit is -25 C, and for steels with a yield strength above 390 MPa - 0 degrees.

Conclusion

We hope that the information presented to the reader will be useful. The video in this article, as usual, contains Additional materials the topics we are discussing. Good luck in construction!

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Topic 7 “Installation of prefabricated reinforced concrete structures”

Issues covered:

General information

Methods for performing installation work

Features of installation of single-story industrial buildings.

1General information

Installation of reinforced concrete structures is the process of their assembly, i.e. installation and fastening in the designed position. Installation includes three types of work:

1. Preparatory:

Unloading Vehicle

Warehousing

Enlarged assembly

2. Basic

Stropovka

Moving to the installation site

Aiming, lowering and installing elements

Their temporary fastening and alignment with finishing to the design position, final fastening, grouting of joints (seams).

3. Final

Sealing a joint (seam) is the process of sealing it with concrete or cement mortar.

Transportation of reinforced concrete materials. Prefabricated structures must be delivered from the manufacturer to the construction site without damage. The enterprise is responsible for loading, and the transporting organization is responsible for safety.

To avoid damage, prefabricated products are placed on vehicles, if possible, in the design position (wall and partition panels in a vertical position or slightly inclined, truss beams in an edge-on position, other elements in a horizontal position.

Transportation of reinforced concrete products can be carried out by road and railway transport.

Installation of prefabricated reinforced concrete structures should be carried out directly from vehicles (“from wheels”); there are three schemes for organizing work “from wheels”:

2. Half-shuttle

3. Shuttle

With the pendulum scheme, a tractor with a trailer is loaded in a warehouse, transports the product to the site, stands in the crane’s installation area, and the crane installs the product directly from the vehicle. At the same time, the tractor stands idle waiting for unloading, and after removing the last product, it leaves the construction site and moves to the warehouse. The number of trailers with this scheme is equal to the number of tractors.

In cases where the idle time of a tractor at a site awaiting unloading exceeds 20% of its operating cycle time, a semi-shuttle scheme is used.

With a semi-shuttle scheme, the number of tractors is 1 less than trailers, because Having delivered the product to the site, the trailer is unhooked from the tractor in the installation area of ​​the crane. While the crane is unloading and assembling products, another, already vacated trailer is attached to the tractor, with which the tractor moves to the warehouse for the next loading of products. If even with this scheme, the downtime of the tractor reaches 20% or more of the process time, then a shuttle scheme is used.

With the shuttle scheme, the number of tractors is 2 less than the number of trailers. With this scheme, the organization of work is as follows: having brought the products to the site, the tractor uncouples from the loaded trailer, hooks up the vacated trailer and goes to the warehouse. There, the empty trailer is uncoupled and left for loading, and the loaded one is attached to the tractor and moved to the object. those. The trailer-coupler is carried out both on site and in the warehouse. In order to calculate how many products can be transported in a particular vehicle, you need to know the weight of the product being transported, the carrying capacity of the vehicle and meet the conditions so that the load factor is in the range of 0.8-1

P – mass of transported products

Q – machine load capacity

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Lecture 16. Installation of prefabricated reinforced concrete and concrete structures. Continuation of the topic.

11.Methods of installation of structures of buildings and structures according to the degree of enlargement of structures, according to the sequence of installation of elements

The variety of design solutions for buildings and structures requires the use of various methods and methods of their installation. The choice of construction method for a building depends on its design and technological features, the degree of enlargement of elements, structural material, mechanization and other factors.

Methods for installing structural elements are directly dependent on the degree of enlargement of installation elements, the sequence of installation of prefabricated elements, the method of installing structures in the design position, the means of alignment and temporary fastening of elements and other characteristics.

Installation methods according to the degree of enlargement of elements. Depending on the degree of enlargement of structures, installation is divided into small-element, element-by-element, large-block, complete block and installation of structures in finished form.

Small-element installation from individual structural elements is characterized by significant labor intensity, incomplete loading of the installation mechanisms due to the large difference in the masses of the various mounted elements, a large number of lifts, and sealing of numerous joints. There is often a need for a device scaffolding for fixing individual elements and enlarged assembly directly into the structure. The method is ineffective and is used extremely rarely.

Element-by-element installation from individual structural elements (columns, crossbars, floor panels, etc.) requires a minimum of costs for preparatory work. Widely used in the construction of civil and industrial buildings, their installation from on-site warehouses and from vehicles.

Large-block installation from geometrically unchangeable flat or spatial blocks, pre-assembled from individual elements. The mass of the blocks is adjusted, if possible, to the maximum load capacity of the mounting mechanisms. This reduces the number of installation lifts and eliminates the need to perform most installation operations at height. Examples of a flat block are the frame frame of a multi-story building, a covering shell block; spatial elements - cell-sized covering blocks of one-story industrial buildings, including trusses, connections, covering structures.

Complete block installation implies the full degree of factory readiness of large blocks of cell size, including already installed communications - sanitary, electrical, ventilation, located between the belts of the trusses. In civil engineering, the method involves the installation of block rooms and block apartments. The building under construction is divided into large-sized, but transportable, structurally complete, fully finished (painting, trim, floors) and assembly units equipped with equipment, which are delivered to the installation site and the buildings are assembled. The weight of such mounting blocks can reach 100 tons.

Installation of finished structures involves assembling the structure completely at ground level with the final connection and fastening of all components, followed by installation of the structure in the design position. The method is used when installing power line supports, radio towers, shells, factory pipes, etc.

Methods for aligning mounting elements to supports. Depending on the method of installing the structure in the design position, the following types of installation are distinguished.

Free installation, in which the mounted element is installed in the design position without any restrictions when it moves freely. The method requires constant monitoring of the position of the element in space during its installation, the need to perform alignment, fastening and other operations at height. The disadvantages of this method are the increased complexity and high labor intensity of the work.

Limited-free installation is characterized by the fact that the mounted structure is installed in guide stops, clamps and other devices that partially limit the freedom of movement of the structure, but lead to a reduction in labor costs for temporary fastening and alignment. The method increases the productivity of crane equipment by reducing the installation cycle time.

Forced installation of a structure is based on the use of conductors, manipulators, indicators and other means that provide complete or specified limitation of structure movements from the action of its own mass and external influences. The method provides increased installation accuracy and leads to a significant reduction in labor costs.

Installation methods according to the sequence of installation of elements. When assembling structures of buildings and structures, the following requirements must be observed:

the assembly sequence must ensure stability and geometric immutability of the assembled parts of the building at all stages of installation;

installation of structures on each section of the building should allow subsequent work to be carried out on the assembled section;

safety of installation, general construction and special works at the site, taking into account their implementation according to a combined schedule.

Depending on the adopted sequence, the installation of structural elements is carried out using the following methods: differentiated (separate), complex and mixed (combined).

The differentiated or separate method is characterized by the installation of similar structural elements, including their temporary and final fastening. For one-story industrial buildings, first all the columns are installed, then all the crane beams, and during the last run of the installation crane, the wall elements are hung. In multi-storey residential buildings, wall panels, partitions, sanitary cabins and other elements are sequentially installed. The work on the floor is completed by laying the floor panels.

The complex method involves sequential installation, temporary and final fastening of various structural elements that make up the frame of one building cell. The installation of elements of another cell begins after the design fastening of the structures of the previous cell. The advantage of this scheme is the opportunity to begin subsequent finishing works and installation technological equipment in cells completed with installation. The method is used for the installation of multi-story frame and frameless buildings, one-story industrial buildings with a metal frame.

A mixed or combined method is a combination of separate and complex methods. Mixed installation is most often used for single-story industrial buildings made of precast reinforced concrete. In the first assembly flow, all columns are installed, in the second flow, crane beams, roof trusses and covering panels are mounted in cells, in the third flow, wall panels are hung. The method is effective when it is possible to provide each editing stream with independent installation means. Installation with the required time offset can be achieved by all three installation mechanisms, which leads to a significant reduction in installation time.

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Installation of prefabricated reinforced concrete structures

Installation of prefabricated reinforced concrete structures of buildings, as a rule, is carried out element by element.

Installation of rafter beams in a vertical plane is carried out by aligning their geometric axes on the supports relative to the vertical. Alignment of crane beams in height should be done at the highest level in the span or on the support using spacers made of steel sheets. If a pack of gaskets is used, they must be welded together, and the pack must be welded to the support plate.

Installation of floor slabs is carried out according to markings on the support beams, which determine their design position. The installation of the covering slabs is carried out using embedded parts in the flange of the rafter beams. Floor slabs are laid on a layer of mortar no more than 20 mm thick, covering slabs are laid dry.

Wall panels are installed using embedded parts on reinforced concrete columns or pre-marked marks on rafter columns. Alignment of panels should be carried out in the plane of the wall and in the vertical plane. After checking the correct installation of structures and acceptance of connections of elements at the interface nodes, the joints are grouted.

Acceptance of completed concrete and reinforced concrete structures is documented in an act in the prescribed form.

1. Installation of enclosing structures

Walls of vertical and horizontal sections are mounted, as a rule, with their preliminary enlarged assembly into so-called “cards”. With an appropriate feasibility study, element-by-element installation is allowed. The enlarged assembly of wall panels into “cards” must be carried out on stands in the operating area of ​​the main installation crane.

Installation of “cards” and panels in plan and height is carried out by combining the installation marks marked on the mounted and supporting structures. The top of the panels is aligned relative to the alignment axes. Before installing the panels, sealing gaskets are placed in the vertical and horizontal joints. When accepting the walls, the reliability of the panels is checked, the absence of damage or instability. Thermal insulation of joints between panels is subject to intermediate control.

The joints of the covering of metal panels that do not have a waterproofing carpet should be sealed with metal covers, while the sides of the upper skin of the panels along the entire length should have a height of at least 60 mm.

1. Concrete works

Dosing of components when preparing a concrete mixture should be done by weight. It is allowed to dose additives introduced into the concrete mixture in the form of aqueous solutions according to the volume of water. Fillers for concrete are used fractionated and washed. It is prohibited to use a natural mixture of sand and gravel without sifting into fractions.

Transportation and supply of concrete mixture is carried out by specialized means that ensure the preservation of the specified properties of the concrete mixture.

Before concreting, all surfaces are thoroughly cleaned of debris, dirt, oils, snow, ice, and cement film. The concrete mixture is laid in concrete structures in horizontal layers of equal thickness without breaks with a consistent direction of laying in one direction in all layers.

During the initial period of hardening, concrete must be protected from precipitation and moisture loss, and then the temperature and humidity conditions must be maintained to create conditions that ensure an increase in its strength.

Measures for the care of concrete, the order and timing of their implementation, control over their implementation and the timing of stripping of structures must be established by the PPR.

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Installation of prefabricated reinforced concrete and concrete structures

1.General installation instructions

3.Installation of columns and frames

4. Installation of crossbars, beams, trusses, floor slabs and coverings

5.Installation of wall panels

6.Installation of ventilation units, volumetric units of elevator shafts and sanitary cabins

7.Construction of buildings using the method of lifting floors

8.Welding and anti-corrosion coating of embedded and connecting products

9.Caulking joints and seams

10.Water, air and thermal insulation of joints of external walls of prefabricated buildings

1.General installation instructions

Preliminary storage of structures in on-site warehouses is permitted only with appropriate justification. The on-site warehouse must be located within the range of the installation crane.

Installation of the structures of each overlying floor (tier) of a multi-story building should be carried out after the design fastening of all installation elements and the concrete (mortar) of the monolithic joints of load-bearing structures reaches the strength specified in the PPR.

In cases where the strength and stability of structures during the assembly process are ensured by welding assembly joints, it is allowed, with appropriate instructions in the project, to install structures of several floors (tiers) of buildings without embedding the joints. In this case, the project must provide the necessary instructions on the procedure for installing structures, welding joints and grouting joints.

In cases where permanent connections do not ensure the stability of structures during their assembly, it is necessary to use temporary installation connections. The design and number of connections, as well as the procedure for their installation and removal, must be indicated in the PPR.

The brands of solutions used when installing bed structures must be indicated in the project. The mobility of the solution should be 5-7 cm along the immersion depth of a standard cone, except for cases specifically specified in the project.

The use of a solution whose setting process has already begun, as well as restoration of its plasticity by adding water, is not allowed.

Maximum deviations from alignment of landmarks when installing prefabricated elements, as well as deviations of completed installation structures from the design position should not exceed the values ​​​​given in table. 12. SNiP 3.03.01-87 “Load-bearing and enclosing structures.”

During the installation process, measurement control must be carried out and a geodetic as-built diagram must be drawn up. The control results must be recorded in special journals.

2.Installation of foundation blocks and walls of the underground part of buildings

The installation of glass-type foundation blocks and their elements in plan should be carried out relative to the alignment axes in two mutually perpendicular directions, combining the axial risks of the foundations with landmarks fixed to the base, or monitoring the correct installation with geodetic instruments.

The installation of strip foundation blocks and basement walls should be done, starting with the installation of lighthouse blocks in the corners of the building and at the intersection of the axes. Lighthouse blocks are installed by combining their axial marks with the marks of the alignment axes, in two mutually perpendicular directions. The installation of ordinary blocks should begin after checking the position of the lighthouse blocks in plan and height.

Foundation blocks should be installed on a layer of sand leveled to the design level. The maximum deviation of the leveling layer of sand from the design level should not exceed minus 15 mm.

Installation of foundation blocks on foundations covered with water or snow is not allowed.

Foundation glasses and supporting surfaces must be protected from contamination.

The installation of basement wall blocks should be carried out in compliance with the dressing. Row blocks should be installed with the bottom oriented along the edge of the blocks of the bottom row, and the top along the alignment axis. External wall blocks installed below ground level must be aligned along the inner side of the wall, and above - along the outer side. Vertical and horizontal seams between blocks must be filled with mortar and embroidered on both sides.

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Types and methods of installation of steel and reinforced concrete structures

The main purpose of reinforced concrete structures is to serve as the supporting frame of a building. The longevity and reliability of the structure depends on how correctly and efficiently they are installed.

The slightest errors in the assembly and installation of this element of the building are fraught with the most serious consequences. Therefore, such work should be carried out by professional and experienced specialists, armed with the necessary equipment. The types and methods of installation of steel and reinforced concrete structures are different, but the ultimate goal is the same - to give the structure maximum stability.

Classification of reinforced concrete structures

Installation of reinforced concrete structures

Installation of metal and reinforced concrete structures depends on the purpose and their design features. According to the criterion of purpose, structures are divided into:

• Foundations;
• Beams;
• Farms;
• Columns;
• Plates.

The first serve as a support for the entire building, the rest - as floors and load-bearing structures, to support frame elements and transfer force from one structure to another.

Based on manufacturing features, structures are divided into:

• Monolithic;
• Prefabricated;
• Prefabricated monolithic.

Monolithic structures are the most durable and reliable. They are used in cases where a large load is expected on load-bearing element. Prefabricated structures are not as durable, are too dependent on weather conditions and can be used where special reliability is not required.

But they are easy to install and convenient for transportation. Prefabricated monolithic structures have fairly high strength and in this indicator are not much inferior to monolithic ones. Therefore, they are often used in the construction of bridges and in the floors of multi-story buildings.

Types of work during installation of structures

Installation of reinforced concrete structures is mainly a matter for professionals

Installation of metal and reinforced concrete structures is divided into the following types of work:

• Foundation installation;
• Installation of walls in the basement of the building;
• Installation of structural elements of the building frame;
• Installation ventilation elements and blocks;
• Installation internal elements building.

Each of these types of work requires adherence to special technology and the use of those steel and reinforced concrete structures that correspond to the assigned tasks.

Initial stage of construction

Before installation, preparatory work should be carried out. Since these structures have considerable weight, it is necessary to consider access to the construction site for vehicles and special equipment (for example, cranes).

Next, geodetic work is carried out to tie the axes of the structure to the terrain. It is also determined which structures and in what quantities should be used. Surveying the area and preliminary calculations allow you to avoid cost overruns and loss of time for reworking incorrectly installed structures.

After transportation to the assembly site, the structures are laid out in the required order. This is a very important and responsible part of the work, because a truss, beam or slab is not a match, and it is very difficult to pull it out from under other structures. The basic rule of layout: if structures are stacked on top of each other, the elements that are installed first should be on top, the bottom row or especially heavy structures should be laid on wooden substrates, free access of equipment to each structure should be provided and the possibility of grasping the part with a crane boom, as well as convenience rafters.

Installation of foundations

The laying and installation of reinforced concrete structures in the pit is carried out according to a pre-drawn diagram, in which the location and order of assembly of all components is precisely marked. Lighthouse blocks are initially laid in the pit. This is the name given to reinforced concrete structures that are located at the corners of the foundation and at the intersections of the axes of the structure.

Monolithic strip foundation

Then cushion blocks are laid, between which technological gaps are left (for example, for passing cables or pipelines). Strip foundation blocks should be located on a sand bed.

Next, the foundation walls and basement floors are installed. The floor panels are welded to the embedded parts in the cushion blocks, and the joints between the panels are filled with cement mortar. Installation of reinforced concrete foundation structures requires constant alignment of the walls with a level, both vertically and horizontally.

Upon completion of installation, an installation horizon is installed - a cement layer along the top of the walls to reach the design mark and level the top edge. After this, the basement is built, and the basement is covered with slabs that form its ceiling and at the same time the floor of the lower floor.

Prefabricated reinforced concrete foundations installed in a slightly different order. First, a slab is laid on the bottom of the pit, onto which the glass block is welded. It is placed on a kind of “bed” consisting of a cement solution. Block foundations are installed by crane, and placing them in correct position carried out by weight.

Installation of columns

Before installation, marks indicating the axes are applied to the four sides of the columns, top and bottom. The columns are laid out in front of the installation site in such a way that the crane makes a minimum of movements, and it is convenient for workers to inspect and secure the structures. The column is installed in a glass mounted on the foundation.

• The column is attached to the crane hook in such a way that when lifted it stands vertically;
• The crane places the column in a vertical position. Depending on the weight of the column, use different ways lifting - rotary, sliding rotation. For stringing columns, friction or pin grips are used;
• Lowering onto the foundation and aligning the position. The column must not be removed from the crane until its correct position has been clearly determined using a level and theodolite.

The column must stand strictly vertically without the slightest tilt. Temporary fastening of the column for its adjustment is carried out using wedge liners.

The next stage is securing the column in the foundation shell. It is produced by injection into the joints of the column concrete mortar(usually a pneumatic supercharger). Once the concrete has reached 50% of its design strength, the wedge liners can be removed. Further work associated with the load on the column, as well as the laying of beams is carried out only after the mixture has completely hardened.

Installation of beams and roof trusses

Reinforced concrete structures

Beams and roof trusses are installed either simultaneously with the roof slabs or separately. Installation of metal and reinforced concrete structures of the main part of the building is carried out depending on the design requirements.

Before installing the trusses, all support areas are aligned and cleaned and axle marks are marked. After this, the structures are delivered to the installation site, slinging and lifting are performed. When placed on a support, the truss or beam is temporarily secured by spacers made of metal pipes, which are attached before lifting begins.

After this, the truss is adjusted and checked for stability and correct installation according to the applied risks. The truss or beam must be positioned so as not to violate the geometry of the building and not to shift relative to the axes of the frame.

Only after a complete check is the element finally secured. The embedded parts are welded to the base plate or column head, as well as to previously installed trusses. You should also weld the washers anchor bolts. Only after the beams and trusses are completely installed can they be unfastened.

After the frame is erected, a horizontal stiffening belt is installed, which is a monolithic reinforced concrete beam running along the upper ends of the load-bearing walls. Its task is to ensure the horizontal rigidity of the structure.

Installation of slabs

Like any installation of reinforced concrete structures, installation of slabs requires preliminary preparation. Scaffolding or fencing must be installed on span trusses. There are two main ways of installing slabs - longitudinal and transverse. In the first case, the crane moves along the span, in the second - across the span. Coating slabs are stacked between columns to be delivered to the coating site.

Building a house

The first slab is laid in a place previously marked on the farm, the rest are placed close to it. If the building is framed, the floor slabs are laid after installing the crossbars, purlins and spacer slabs, and if it is frameless, after the walls are built. When laying the slab on the surface, a “bed” is made from the mortar. Excess solution is squeezed out by the plate itself. The first plate must be welded to the truss in four nodes, the subsequent ones in three. Inter-joint seams are sealed with a solution of cement and sand.

Installation of wall panels

Wall panels are installed after the building frame has been erected and the floors have been laid. Before lifting, the panels are grouped into cassettes. With this storage method, the installation of metal and reinforced concrete structures intended for the construction of walls is the most rational. Cassettes can be located between the wall and the tap, behind the tap, as well as in front of it.

The panels are installed by installers only from the inside of the building. Wall panels are placed along the entire height of the building with a section between two columns. Therefore, one cassette must contain such a number of panels to cover the entire area along its entire height.

The panel is accepted by installers at the junction of this structure with the column. To do this, it is necessary to provide workers with access to these points in advance. If there is no transverse overlap, you will have to install cradles, scaffolds or a lift.

The installation of the first row of panels is of particular importance, so their position and compliance with the applied risks is checked especially carefully. External panels perform not only support and protective, but also aesthetic functions. Therefore, the seams between the panels must be sealed not only carefully, but very carefully and not exceed the established standards.

Internal wall panels are installed before the installation of the upper floor slabs. The panels are fastened to the columns with clamps, and to the floor slabs with struts. The final fastening of the wall panels is carried out by welding them to the elements of the building frame.

Features of metal structures

A distinctive feature of metal building structures is their tendency to deform, significant weight and special precision in manufacturing. Therefore, transportation, laying, lifting and installation require special care and attention.

In general, the installation of metal and reinforced concrete structures is not fundamentally different, but hardware They are often prefabricated, which allows them to be assembled not only on the ground, but also directly at the installation site.

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Methods of installation of reinforced concrete structures of frame buildings

Methods and technology for installing elements of frame buildings depend on their design solutions, number of storeys and available installation equipment.

It is recommended to install frames of multi-story buildings with two-story columns using group or hinged conductors. This ensures forced fixation of the columns in the design position during their installation, thereby reducing the amount of alignment work. The remaining frame elements are mounted using the free method.

It is recommended to install the frames of one-story and low-rise industrial and administrative buildings using the limited-free method using single or group conductors.

The most important rule that must be followed in any organization and installation method is to ensure the stability of the mounted structures. In this regard, any installed structure cannot be released from the crane hook until it is securely fastened. The sequence of installation of frame elements must be such that the rigidity and geometric immutability of the mounted part are ensured.

Taking into account this requirement, when constructing the frame of one-story industrial and other buildings, it is recommended to follow the following order: the first to be installed at each site (capture) are the structures between which the connections are located (vertical, horizontal, etc.). Each next structural element is connected to the previously installed one with connecting elements provided for by the project: crossbars, braces or temporary struts and braces.

Prefabricated elements of multi-storey buildings in each section (section) are mounted in the following sequence. First, the columns and crossbars of the frame are installed in the stiffening cell or starting from the end of the building (section) along its entire width and on all floors of the tier. After aligning the position of the columns and crossbars and securing them, connections or tie panels and spacer floor slabs are installed between the columns. Then the internal panels are installed staircase, landings and flights, external wall panels of the staircase, ventilation blocks, sanitary cabins, wall panels of external walls and partitions. After assembling the elements of one section and securing them by welding, the crane is moved to the next section, and the welding work is completed on the assembled section, the joints are sealed, and the floor slabs are installed. Installation work is carried out in the same sequence in all subsequent sections of the tier.

The installation of the second tier begins only after alignment of the installed structures, welding of all installation joints of the first tier and monitoring with geodetic instruments of the correct installation of the structures and the layout of the axes and marks for the subsequent installation of the structures.

Before starting the installation of structures on each tier, which may include two or three floors (depending on the cutting of the columns along the height of the building), the main alignment axes of the building are marked on the floor or column heads, the installation horizon is determined, and axial and other installation risks are marked. The axle marks are measured each time from the main alignment axes and checked mutual arrangement adjacent axes.

The most common multi-storey residential, public and industrial frame buildings are with frame cells of 6 x 6 and 9 x 9 m; other spans are also possible, for example 12 m and intermediate ones. Floor height 3; 3.3; 3.6; 7.2 m. The width of buildings is most often 12; 18; 24 and 36 m. B upper floors There can be halls up to 10.8 m high, spanning the entire width of the building or part of it, including with or without overhead cranes. The length of the building is a multiple of the cell parameter.

For load-bearing frames, columns are used for one, two, three floors. Depending on the space-planning decisions, buildings are built with transverse or longitudinal arrangement of crossbars, along which floor slabs are laid, respectively, in the longitudinal or transverse direction.

Assembling a building frame is an interconnected process of installing columns, crossbars, stiffening diaphragms, tie-down and interfloor floor slabs. The elements are installed in a sequence that ensures the rigidity and spatial immutability of the frame. The installation sequence in each specific case is determined by the work plan and the set of installation equipment that will be used for installation and alignment of structures: individual (single) or group devices.

Installation using individual mounting equipment.

In construction, individual installation equipment is most often used, with the help of which structures are aligned and temporarily secured. The sets of individual installation equipment for the installation of multi-story frames include (see diagram below, pos. a... c): wedges and liners, support beams, anchor devices, clamps, struts and horizontal struts, conductors. Unlike group ones, individual products are more versatile and easy to use (Fig. 1).

Rice. 1 - Schemes for installing multi-storey columns using a set of individual installation equipment: a - arrangement of columns and devices, b - securing the column with struts, c - clamp for securing the struts to the column; 1 - foundation glass, 2 - inventory beam, 3 - column, 4 - clamp, 5 - strut, 6 - strut tow bar, 7 - wedges, 8 - anchor device, 9 - crimp rope

Wedges and wedge liners are used for alignment and fastening of columns in foundation glasses.

The support beams consist of two channels connected by strips and have loops in the upper part for attaching struts, and in the lower part - end stops for fastening to the foundation glasses (see diagram above, pos. a, b).

Anchor devices 8 are a U-shaped frame with holes in the upper part through which a gripping hook passes, moved by a tension nut.

The clamp (see diagram above, item c) for attaching the strut to the column is made in the form of an angular stop, which is secured to the column using a rope with a tension device.

The struts 5 consist of telescopically connected pipes with tensioning towbars 6 and gripping devices at the ends for fastening to the loops or eyes of the clamp and loops of support beams or other structures.

Conductors are designed for temporary fastening and alignment of columns that are joined in height to the heads of previously installed columns.

The columns of the first assembly tier are installed using the same methods as when installing one-story buildings. However, in this case, struts and spacers are installed to hold the columns in such a way that they do not interfere with the laying of crossbars and tie plates between the columns. Before the installation of the columns begins, support beams 2 are laid on the grip (see diagram above) and secured to the foundation loops using anchor devices. Support beams are not laid in those places where frame stiffening diaphragms are installed.

A clamp 4 is put on the assembled column in the warehouse and two struts 5 are hung on it, after which the column is slung and lifted by a crane. The column submitted for installation is installed in the foundation shell and temporarily secured using wedge liners (wedges) 7 and two struts 5. After this, the column is slinged and aligned. The column is installed in a vertical position using theodolites along two axes. As installation proceeds, the columns are embedded in the foundation cups. The struts are removed from the columns after the frame has been secured with crossbars and slabs at a level of two lower floors.

The crossbars are mounted after the columns (see diagram below, pos. a... c). Before installation, the crossbars are cleaned, the reinforcement outlets are straightened, the embedded parts are straightened, and the crossbars are supported dry on the column consoles. On each structural cell of the building, first the lower and then the upper crossbars are installed. The installers' workplace is on the inventory sites.

The work is performed in the following sequence. A 3rd category installer rigs the crossbar and gives the command to the crane operator to lift. The driver moves the crossbar with a crane to the installation site. A 5th category installer supervises the operation of the crane. Installers of the 4th and 3rd categories, being on the adjustable scaffolding platforms, take the crossbar, lay it on the shelves and check it.

In the transverse direction, the crossbars are installed in the design position, aligning their axes (upper reinforcement outlets) with the axes (reinforcement outlets) of the columns; in the longitudinal direction, maintaining equal support areas for the ends of the crossbar on the column console (the difference in the support areas for the ends of the crossbar on the console should not exceed ± 5 mm).

After aligning the crossbars, their supporting embedded parts are tack welded to the embedded parts of the column consoles and the crossbar is slinged (Fig. 2).

Rice. 2 - Installation of the crossbar: a - applying an axial mark to the column, b - installation of the crossbar, c - straightening the crossbar during alignment

Having made sure that the columns and crossbars in the assembled cell are in the design position, the installers finally secure the crossbars by bath welding the fittings, welding embedded parts, and grouting the joints (after completion according to the welding report). Then the frame stiffening diaphragms are mounted (see diagram below, pos. a, b) with a shelf replacing the crossbar (Fig. 3).

Rice. 3 - Installation of internal walls - stiffening diaphragms - in a frame building: a - installation, b - temporary fastening; 1 - strut, 2 - diaphragm with a shelf replacing the crossbar, 3 - universal sling, 4 - adjustable clamp with stand

For temporary fastening and alignment of diaphragms, adjustable clamps 4 are used. Frame stiffening panels without a shelf replacing the crossbar are mounted before installing the crossbar in this span. In this case, instead of temporary fastenings of the frame at the installation site of the diaphragm, equivalent fastenings are installed on the other side of the column, for example, horizontal bracing braces. The organization of the workplace and the sequence of operations are shown in the diagram below, pos. a, b.

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USSR STATE COMMITTEE FOR CONSTRUCTION (GOSSTROY USSR)

SNiP III-16-80

BUILDING REGULATIONS

Part III

RULES FOR PRODUCTION AND ACCEPTANCE OF WORK

Chapter 16

CONCRETE

AND PREFABRICATED REINFORCED CONCRETE STRUCTURES

Approved

by resolution of the USSR State Committee for Construction Affairs

MOSCOW STROYIZDAT 1981

3.9. The installation of structures should begin, as a rule, with a spatially stable part of them: a bracing panel, a stiffening core, etc.

Installation of building structures and structures long distance or heights should be made in spatially stable sections (spans, tiers, floors, temperature blocks, etc.).

EVIL. Installation of the structures of each overlying floor (tier) of a multi-story building must be carried out after the concrete (mortar) of the cast-in-place joints of load-bearing structures reaches the strength specified in the work plan.

Until this strength is achieved, conductors and other devices that temporarily secure structures should not be removed.

3.11. In cases where the strength and stability of assembled structures under the influence of installation loads are ensured by welding of installation joints, it is allowed, with appropriate instructions in the project, to carry out work on the installation of structures of several floors (tiers) of a building without embedding the joints. In this case, the project must provide the necessary instructions on the procedure for installing structures, welding joints and embedding joints.

3.12. Installation of structures of multi-storey buildings, the stability of which during the installation period is ensured by fastening to brick or block walls, must be carried out simultaneously with the construction of the walls or provided that the laying of the walls lags behind the installation of the frame by no more than one floor; the strength of the mortar in the joints of the masonry walls at the time of installation of the structures of the overlying floor must be indicated in the project.

In winter, the stability of such a frame can be ensured by temporary installation connections, if they are provided for in the project; These connections may be removed only after the walls have been erected on a given floor, the frame structures have been attached to the walls, and the mortar in the wall seams has achieved the strength specified in the design.

With appropriate economic justification, it is allowed in agreement with the design organization

use temporary installation connections also when installing structures in the summer.

3.13. The use of temporary connections is also allowed in cases where permanent connections do not ensure the stability of structures during installation or the installation of these connections is impossible until the verification of the mounted structures is completed.

3.14. The combined installation of structures and equipment must be carried out according to work plans containing interconnected diagrams of installation tiers and zones, and lifting schedules for structures and equipment.

3.15. Before lifting structures you should:

clean the lifted, as well as previously installed adjacent structures from dirt, debris, snow, ice, and metal parts- from deposits of concrete and rust, in this case it is not allowed to remove ice with hot water, steam, sodium chloride solution, it is prohibited to use a fire method to remove ice from the surface of panels that have thermal insulation liners and contain combustible materials; It is recommended to remove ice using hot air, scrapers, wire brushes, etc.;

check the conformity of the design markings of structures;

check the position and presence of embedded parts and installation marks;

equip structures with installation scaffolds and ladders in accordance with the requirements of the work project and prepare the workplace for receiving structures, checking the availability at the workplace connecting parts and necessary auxiliary materials;

check the correctness and reliability of securing the load-handling devices.

3.16. When slinging and lifting structures, the following rules must be observed:

at. When slinging with steel ropes, inventory pads should be installed under them to avoid damage to the concrete and rope;

when lifting, lifting devices should be used

swarms that ensure uniform transfer of loads to the structures being lifted and slings.

Slinging should be done using inventory slings or special gripping devices with semi-automatic devices for remote slinging.

3.17. Slinging of structures must be carried out in the places specified in the design and ensure the lifting and supply of elements to the installation site (laying) in a position close to the design one. If, due to installation conditions, it is impossible to sling structures in the places specified in the project, changing the slinging locations must be agreed upon with the design organization. It is prohibited to sling structures in arbitrary places, as well as behind reinforcement outlets. Load-handling devices and the slinging scheme for enlarged flat and spatial blocks must ensure that the geometric dimensions and shape of these blocks remain unchanged during lifting and delivery to the installation site.

3.18. The use of installed structures for attaching cargo pulleys, outlet blocks and other load-lifting devices to them is permitted only in accordance with the work plan agreed upon with the organization that developed the building (structure) design.

3.19. Lifting of structures should be done smoothly, without jerking, swinging or rotating the elements being lifted, usually using guy ropes. For guy ropes, hemp (according to GOST 483-75 *) or nylon (according to GOST 10293-77) ropes with a diameter of 19-S-24 mm should be used. When lifting vertical rod structures, one guy rope is used, horizontal and plane ones - at least two.

3.21. Installation of structures in the design position must be carried out according to accepted guidelines (marks, pins, stops, edges, etc.). Structures that have special mortgages or other fixing devices are installed using these devices.

3.22. Unslinging the installed const.

Handlings are permitted only after they are securely secured with permanent or temporary connections. Temporary fastening of installed structures should ensure their stability and unchangeable position until permanent fastening is performed.

3.23. Before performing permanent fastening of structures, the compliance of their location with the design and the readiness of the mounting interfaces for welding and sealing of joints must be checked; the results of the inspection are recorded in the installation log.

3.24. The brand and mobility of solutions used during the installation of structures are established by the project. The use of a solution whose setting process has already begun is not permitted. Structures displaced from the mortar bed during the hardening period of the mortar must be lifted and, after cleaning the supporting surfaces of the old mortar, reinstalled on fresh mortar.

3.25. The maximum deviations of the actual position of the mounted structures from the design one should not exceed the values ​​​​given in clause 6.3. When installing structures, the position of which may change during their permanent fastening and installation of subsequent structures, the specified maximum deviations must be assigned in the work design based on calculation of accuracy depending on design solutions, installation devices, sequence of work, welding technology, etc. keeping in mind not to exceed the values maximum deviations given in clause 6.3.

3.26. During installation, structures must be protected from damage. Damaged structures must be replaced or repaired in agreement with the design organization.

Installation of foundations, columns and frames

3.27. The installation of prefabricated foundations should be carried out by combining the marks marked on them with landmarks fixed to the foundations, or control

ensuring correct installation using geodetic instruments.

3.28. Foundation glasses and supporting surfaces must be protected from contamination.

3.29. Installation of prefabricated foundations on foundations covered with water or snow is not permitted.

3.30. Installation of prefabricated strip foundations should begin with lighthouse elements installed at the intersection of the axes of the building walls. Ordinary elements are mounted after instrumental verification of the position of the lighthouse elements in plan and height.

3.31. Columns and frames should be installed by combining the marks indicating the geometric axes in the lower section of the mounted structure with the marks:

alignment axes - when installing columns in foundation glasses;

geometric axes of the structures below - in all other cases.

Note If there are embedded fixing devices, the installation of columns (frames) is carried out using these devices.

8.22. Alignment of the design position and temporary fastening of columns and frames in the foundation glasses, as a rule, should be done using inventory mechanical devices that ensure the specified installation accuracy and high labor productivity. The use of wedges is permitted as an exception with appropriate justification in the work project.

3.33. The design elevations of the bottom of columns when they are installed in foundation glasses should be ensured by the use, if necessary, of reinforced concrete underlays, the strength of which is determined by the design.

3.34. Preparation of the bottom of the foundation cups for the installation of columns manufactured with increased precision for their non-alignment installation must be ensured by molding a concrete mixture placed on the bottom of the foundation cup, with special devices and methods provided for by the work project. The forming surfaces of these devices must ensure the slope of the supporting surfaces of the bottom of the cup

foundation from the horizontal or design plane no more than 1/1250.

Deviations of the actual elevations and dimensions of the molded bottom of the foundation cups from the design ones during unaligned installation of columns should not exceed:

5 mm for the displacement of devices or parts that fix the position of the places where columns are supported in the foundation glasses in plan relative to the alignment axes;

3 mm in deviation of the bottom marks of the glasses in the places where the columns support.

3.35. Bringing the top of columns or frames into the design position should be done relative to the alignment axes along two mutually perpendicular vertical planes.

In cases where during installation it is necessary to ensure full contact of the ends of the joined columns, the methods for their alignment must be indicated in the project.

3.36. When installing buildings using systems of group mounting devices (rigid or articulated conductors, etc.), special attention should be paid to the accuracy of installation and the rigidity of fixing the base elements.

3.37. Removal (rearrangement) of mounting devices should be done after permanent fastening of columns and frames in nodes and installation of connecting elements.

3.38. Installation of structures on columns resting on glass-type foundations is allowed only after the columns have been grouted in glasses and the concrete has reached the strength specified in the project, and in the absence of such instructions, not less than 70% of the design grade for compressive strength.

Note In some cases, it is allowed to install overlying structures on columns and frames before they are embedded in foundation cups, provided that the strength and stability of the columns and foundations from temporary and installation loads is ensured in accordance with the work design.

Installation of beams, crossbars, trusses and slabs

3.39. The design position of trusses, beams and crossbars must be ensured by combining the marks applied to the mounted and supporting structures.

3.40. Crane beams should be installed with temporary fastening, ensuring their subsequent alignment within the individual spans of the building.

3.41. Before bridging, trusses and beams must be aligned and secured to supporting structures in accordance with the design or secured with temporary ties (braces) provided for by the PPR.

3.42. Covering slabs should be laid after installing each next beam or truss and the connections provided for by the design.

Note. In some cases, due to the peculiarities of design solutions or specific construction conditions, the work plan may provide for a different installation sequence.

3.43. The order and direction of laying the slabs must be indicated in the work design and ensure the stability of the erected structure and the possibility of welding the slabs to load-bearing structures in accordance with the project.

3.44. When laying floor slabs, it is necessary to ensure the dimensions of the areas for supporting the slabs on the supporting structures specified by the design and to level the front surfaces of the slabs.

3.45. When laying slabs along the upper chords of beams, crossbars and trusses, you should especially control the position of the supporting ribs of the slabs relative to the centers of the truss nodes along their chords and the dimensions of the support areas.

3.46. Covering slabs should be secured to rafter structures after installing each slab.

3.47. When laying floor slabs in multi-storey buildings, spacer slabs should be installed and secured first.

Installation of wall panels

3.48. When installing wall panels (partitions) of buildings with single-row cutting, the edges of the elements or the installation marks on them must be aligned with the reference marks placed from the alignment axes on the reference planes. When cutting multiple rows, the panels of the first row from the overlap should be installed

similar to the installation of panels during single-row cutting, and the panels of subsequent rows, combining the edges of the installed panel with the edges of the underlying one.

3.49. If there are sinking or protruding parts (loggias, bay windows) on the facade of the building, the installation of panels of external load-bearing and self-supporting walls should be carried out according to templates.

3.50. When installing panels of external walls of buildings below ground level (basement walls), they should be aligned along the inner plane of the wall.

3.51. The position of the wall panels in height should be adjusted by beacons (support tables) or by the marks of elevation marks. Control of the verticality of wall panels should be carried out along the longitudinal edge.

3.52. Installation of wall panels and partitions, as a rule, should be done using group mounting devices. Bringing these structures into the design position and temporarily securing them must be carried out using fixing devices included in the fixtures. Special attention it is necessary to pay attention to the rigidity of the base element.

3.53. Installation of wall panels and partitions that have special embedded fixing devices (pins, plates with cutouts, etc.) should be carried out using these devices.

3.54. When installing panels with smoke and ventilation ducts, the combination of these channels must be ensured. Do not allow solution or other foreign objects to enter the channels. Vertical channels should be protected from clogging and precipitation immediately after installing the panel.

Installation by lifting floors and floors

3.55. When constructing buildings using the method of lifting floors (floors), the presence of design gaps between columns and slab collars, between slabs and walls of stiffening cores throughout their entire height, as well as the cleanliness of the holes for lifting rods provided by the design must be checked.

3.56. Before lifting begins, lifting equipment, communication and signaling equipment must be installed and tested, conductors for building up columns, towers and scaffolds for servicing lifts and temporarily securing the slabs being lifted must be prepared, and means of protecting electrical wiring must be installed.

3.57. The equipment used must ensure uniform lifting of floor slabs relative to all columns. The deviation in the marks of individual support points on the columns during the lifting process should not exceed 1/300 of the span and be no more than 20 mm, unless other values ​​are specified by the project.

3.58; Raising floors (floors) should be carried out after the concrete slabs reach the strength specified in the project.

3.59. Slabs raised to design level must be secured with permanent fastenings; at the same time, acts of intermediate acceptance of completed structures are drawn up.

3.60. Before lifting completely finished floors, the joints of all structures, except for the joints in places adjacent to the stiffening core and columns, must be welded and cemented with the installation of sealants. The sealant is laid in the upper horizontal seams of the walls before the last rise of the floors to the design position.

4. WELDING AND ANTI-CORROSION COATING OF EMBODIED AND CONNECTING ELEMENTS

4.1. Welding of structures should be carried out in accordance with the Instructions for welding connections of reinforcement and embedded parts of reinforced concrete structures according to the work project technological process* establishing the sequence of assembly and welding work, welding methods, the order of seams, welding modes, diameters and grades of electrodes and wire, requirements for other welding materials.

4.2. Connections of reinforcement with round plates and flat elements made of rolled steel, beyond

inclusion of parts with anti-corrosion coating may be carried out in accordance with current regulatory documents without developing special technology.

4.3. Welding must be carried out by electric welders who have certificates establishing their qualifications and the nature of the welding work for which they are authorized.

4.4. All welding materials must be tested before use input control, in which it is necessary to check the availability of certificates from manufacturers, as well as the compliance of the materials themselves with the project and their suitability.

4.5. The types of electrodes and brand of welding wire are indicated in the project. In the absence of such instructions, welding materials should be used for welding in accordance with the Instructions for welding reinforcement joints and embedded parts of reinforced concrete structures. It is allowed to use other welding materials that meet the requirements of GOST 10922-75.

4.6. Welding materials must be stored in conditions that protect them from moisture, contamination and mechanical damage.

Before starting welding work, electrodes, flux-cored wire and flux must be calcined according to the conditions specified in the technical specifications and data sheets and stored separately from undried and non-calcined ones. The welding wire must be cleaned of rust, grease and other contaminants.

4.7. Calcined electrodes, flux-cored wire and flux should be supplied to the workplace in quantities necessary for the welder to work during one shift. At the workplace, welding materials must be kept in conditions that prevent them from getting wet.

Storage and transportation of calcined welding materials must be carried out in closed, moisture-proof containers.

4.8. The structural elements to be welded must first be cleaned to bare metal on both sides from the edges to at least 10 mm from mortar, concrete deposits, bitumen, paint, rust, grease stains and other contaminants and dried.

UDC "ODCL"<ШЛ5)

SNnP Sh-16-80. Prefabricated concrete and reinforced concrete structures./Gosstroy of the USSR. - M.: Stroyizdat, 1981 - 32 p.

This 1st chapter was developed by the TsNIIOMTP Institute of the USSR State Construction Committee with the participation of VNIPI PromstadBKonstruiyashchia of the USSR Ministry of Installation and Special Construction. With the entry into force of this chapter, Chapter* SNiP III-16-73 “Prefabricated concrete and reinforced concrete structures” and “Instructions for the installation of prefabricated reinforced concrete structures of industrial buildings and structures” (SN 319-65) become invalid.

Editors - nj. EL V" Bakonin (Gosstroy USSR), candidates of technical sciences. Sciences V. N. Sverdlov and Sh, L. Machabeli (TsNIIOMTP Gosstroy USSR), engineers V. Ya. Glikin and B. Ya. Moizhes (VNIPI’ Promstalkonstruktsiya Mshshentazh-special construction of the USSR)

WITH--. Instruction standard, \ issue, -1.9-80. 3201000000

© Stroyizdat, 1981

If necessary, immediately before welding, cleaning of the parts to be welded should be repeated.

4.9. Before welding, structures must be checked to determine the correctness of their assembly and preparation of joints for welding.

4.10. The cutting of edges and the size of gaps in structural elements assembled for welding must be carried out in accordance with the requirements of GOST 14098-68 and the Instructions for welding reinforcement joints and embedded parts of reinforced concrete structures.

The outlets of rods and other elements to be welded must be coaxial and free of bending.

4.11. Tack work on assembled parts must be carried out by electric welders or assembly workers who have the right to carry out welding work in accordance with clause 4 3, using welding materials of the same type and quality as the main seams of welding joints.

4.12. When installing transverse rods (clamps) at joints, it is not allowed to use tack welding and welding at the intersection of these elements with longitudinal reinforcement made of steel of classes A-P and A-Sh.

4.13. During the welding process, the joints being welded must be protected (using tents, screens) from precipitation and wind.

4.14. Manual and semi-automatic arc welding of structures at temperatures down to minus 30° C should be carried out using conventional technology, but the welding current should be increased by 1% when the temperature drops below 0° C for every 2.5-3° C. Welding at temperatures below minus 30°C is not allowed.

4.15. At the end of welding, the welded joints must be cleaned of slag and splashes of molten metal.

4.16. On critical welded joints, the welder's number or mark (stamp) must be stamped or punched in the places indicated on the drawing.

4.17. The performance of welding work must be documented with inspection reports for hidden work.

4.18. Quality control of welded joints should be carried out:

USSR State Committee for Construction Affairs (Gosstroy USSR)

I. GENERAL PROVISIONS

1.1. The rules of this chapter must be observed during the production and acceptance of installation work of prefabricated concrete and reinforced concrete structures of buildings and structures. When installing structures, the requirements of the chapters of SNiP on the organization of construction production and safety precautions in construction, state standards for reinforced concrete and concrete products, fire safety rules during construction and installation work and other regulatory documents approved or agreed upon by the USSR State Construction Committee must also be observed.

1.2. When installing structures of hydraulic structures and bridges, as well as structures of buildings and structures erected on permafrost and subsidence soils, undermined areas and in seismic areas, the relevant requirements of other chapters of SNiP and special requirements of the project must, in addition, be met.

A. When performing work on the installation of prefabricated concrete and reinforced concrete structures, in order to ensure the required quality of work at all stages, production control must be carried out as provided for by the chapter of SNiP on the organization of construction production.

1.4. Projects for the installation of structures must include: the sequence of installation of structures; measures to ensure the required installation accuracy, spatial immutability of structures during their enlarged assembly and installation in the design position, as well as the stability of the building (structure) during the installation process; the procedure for combining the installation of structures and technological equipment, as well as additional requirements for the performance of general construction work, installation of technological and engineering equipment and the manufacture of structural elements related to local peculiarities of installation conditions.

1.5. In all cases, confirmed by relevant technical and economic calculations, installation methods with spatial self-fixation of structures, using group installation equipment systems and with preliminary enlargement of mounted structures should be used, ensuring increased labor productivity and installation accuracy.

1.6. The order for structures should, in agreement with the manufacturer, include additional technical requirements for the manufacture of non-standard structures, justified by accepted installation methods, in terms of:

dividing structures into sending elements depending on the load-carrying capacity of the installation mechanisms adopted in the work production project;

installation of additional embedded parts in structural elements, as well as making holes for fastening mounting devices (links, clamps, etc.) and scaffolding attachments. These parts or openings should be located so as to ensure unloading, storing and installation of structural elements without compromising their strength;

position of structural elements when loading them onto vehicles;

location of installation connections, which should be installed in places accessible for embedding and electric welding;

interfaces of structures manufactured at the factory in the form of individual elements with subsequent enlargement

on the installation site, which does not require tilting of structures;

locations of installation marks;

manufacturing structures with increased precision for non-alignment installation.

Additional technical requirements must be agreed upon by the installation organization with the organization that completed the working drawings for the construction part of the project.

1.7. Before installation begins, work must be carried out on setting up and accepting installation mechanisms and equipment, arranging assembly scaffolds, circles, stands, racks, supports, rolling tracks, load-handling devices, etc.

1.8. When checking the correct choice of types of cranes, installation devices, equipment and installation methods, one should proceed from the number, dimensions and weight of the installed structural elements, the configuration and dimensions of the buildings and structures being erected, the temperature and climatic conditions of the construction area, as well as the requirements for ensuring the stability of the cranes.

1.9. Installation should, as a rule, be carried out directly from vehicles or with preliminary layout of structures in the operating area of ​​the installation mechanism. The placement of structures on vehicles must ensure the installation sequence specified by the design.

The construction of on-site warehouses is permitted subject to an appropriate feasibility study.

1.10. In all cases justified by the work design, structures should be mounted in flat or spatial blocks, including technological, sanitary and other engineering equipment.

1.11. Delivery of structures to the construction site must be carried out subject to the concrete strength meeting the tempering strength, which is established on the basis of state standards by the manufacturer in agreement with the consumer and the design organization.

1.12. Data on installation work must be

must be entered daily into the logs of installation work (Appendix 1), welding work (Appendix 2), anti-corrosion protection of welded joints (Appendix 3), concreting joints (Appendix 4), and also recorded during installation on as-built diagrams.

1.13. During installation work, hidden work on reinforcing joints and assemblies, welding of fittings and embedded parts, protecting steel parts from corrosion, as well as other work are subject to inspection and acceptance in the manner established by the head of SNiP on the organization of construction production.

Subject to intermediate acceptance are foundations, supports, structures that have undergone enlarged assembly, and other critical structures in accordance with the list given in the project.

2. TRANSPORTATION AND INPUT QUALITY CONTROL OF STRUCTURES

2.1. When loading structures onto vehicles and unloading them, the scheme for slinging and arrangement of structures on vehicles and storage areas given in the project must be observed.

2.2. When transporting and temporarily storing structures in the installation area, the following requirements must be observed:

structures should, as a rule, be in a position close to the design (beams, trusses, slabs, panels, etc.), and if this condition cannot be met, in a position convenient for transportation and transfer for installation (columns, frames and etc.);

structures must be supported by inventory pads and rectangular gaskets located in the places specified in the design; the thickness of the linings and gaskets must be at least 30 mm and at least 20 mm higher than the height of the sling loops and other protruding parts of the structures. When multi-tiered loading and storage of similar structures, linings and gaskets should be located on the same vertical along the line of the lifting devices.

swarms (loops, holes) or in other places indicated in the working drawings;

structures must be reliably strengthened to protect them from overturning, longitudinal and lateral displacement, mutual impacts between themselves or against the structure of vehicles. Fastenings must ensure the possibility of unloading each element from vehicles without disturbing the stability of the others;

textured surfaces must be protected from damage and contamination;

reinforcement outlets, threads of anchor bolts, embedded and welded parts must be protected from damage;

factory markings must always be available for inspection;

Small parts for assembly connections should be attached to shipping items or sent simultaneously with structures in boxes, which should be provided with tags indicating the brands of parts and their quantities. These parts should be stored under cover.

2.3. Transportation of large-sized structures by road, as well as structures that require special transportation conditions, should be carried out using specialized vehicles: panel trucks, truss trucks, slab trucks, etc.

2.4. Transportation of structures by rail should be carried out in accordance with the “Technical conditions for loading and securing cargo” approved by the Ministry of Railways in 1969.

2.5. When carrying out incoming inspection of prefabricated concrete and reinforced concrete structures delivered to the construction site, one should check the presence of a passport, marks and marks provided for in the working drawings, protection from moisture for structural elements made of lightweight and cellular concrete, open areas of insulating layers of wall panels, as well as the absence of damage during loading and unloading operations and transportation.

2.6. When carrying out incoming inspection of structures delivered to the construction site, it is necessary

check their completeness, including the presence of steel parts necessary for installation connections.

2.7. Structural elements during storage should be stacked as follows: wall panels, trusses and rafter beams - in cassettes in a vertical position; floor and coating slabs - horizontally, in stacks no more than 2.5 m high; crossbars and columns - horizontally, in stacks up to 2 m high.

2.8. During temporary storage, structures must be sorted by grade and laid out taking into account the order of installation.

2.10. Transportation and temporary storage of standardized concrete and reinforced concrete structures (products) should be carried out in accordance with the requirements of state standards for specific types of products.

3. INSTALLATION OF STRUCTURES General instructions

3.1. The enlarged assembly of reinforced concrete structures should be carried out on stands that allow the position of the elements to be recorded and their careful alignment and straightening to be carried out during the assembly process. You should first check the dimensions of the structural elements being enlarged, the presence and correct location of embedded parts.

3.2. By the beginning of installation, the strength of the mortar (concrete) at the joints of enlarged structures must be no lower than the release strength of the mortar (concrete) in these structures, unless otherwise specified in the project.

3.3. Maximum deviations of the actual dimensions of enlarged structures from the design ones should not exceed the values ​​​​established by the relevant state standards or technical specifications for these structures.

3.4. The assembly of structures that have reinforcement outlets at the joints must be carried out by checking the correct installation of the elements and the alignment of the reinforcement outlets; in this case, measures must be taken to ensure that the outlets are not bent.

If necessary, adjustments to reinforcement outlets should be made without violating the design position of the rods and preventing damage to the concrete. Joining bent rods and linings, unless specifically specified by the project, is prohibited.

3.5. Installation of structures is permitted only after acceptance of foundations and other supporting elements, including geodetic verification of compliance of their planned and altitude position with the design one, with the drawing up of an as-built diagram.

3.6. When installing structures, constant geodetic assurance must be carried out to ensure the accuracy of their installation with determination of the actual position of the mounted elements. The results of geodetic control after the final fastening of the structures of individual sections and tiers must be documented in an as-built diagram.

3.7. Until the completion of the alignment and complete fastening of the structures in the design position, it is not allowed to support the overlying structures on them, if such support is not provided for in the work design.

In cases justified by the work design, it is allowed to install overlying structures with temporary or incomplete fastening of the underlying ones, while temporary or incomplete fastening of structures must be justified by calculation of their weight, wind, snow and installation loads.

3.8. During installation, the strength and stability of structures must be ensured under the influence of their own weight, installation loads, snow and wind, which is achieved by observing the installation sequence provided for by the PPR, observing the design dimensions of the support platforms and mates, as well as timely installation of permanent or temporary connections and fastenings provided for by the project .

The main purpose of reinforced concrete structures is to serve as the supporting frame of a building. The longevity and reliability of the structure depends on how correctly and efficiently they are installed.

The slightest errors in the assembly and installation of this element of the building are fraught with the most serious consequences. Therefore, such work should be carried out by professional and experienced specialists, armed with the necessary equipment. The types and methods of installation of steel and reinforced concrete structures are different, but the ultimate goal is the same - to give the structure maximum stability.

Classification of reinforced concrete structures

Installation of reinforced concrete structures

Installation of metal and reinforced concrete structures depends on the purpose and their design features. According to the criterion of purpose, structures are divided into:

• Foundations;
• Beams;
• Farms;
• Columns;
• Plates.

The first serve as a support for the entire building, the rest - as floors and load-bearing structures, to support frame elements and transfer force from one structure to another.

Based on manufacturing features, structures are divided into:

• Monolithic;
• Prefabricated;
• Prefabricated monolithic.

Monolithic structures are the most durable and reliable. They are used in cases where a large load is expected on the load-bearing element. Prefabricated structures are not as durable, are too dependent on weather conditions and can be used where special reliability is not required.

But they are easy to install and convenient for transportation. Prefabricated monolithic structures have fairly high strength and in this indicator are not much inferior to monolithic ones. Therefore, they are often used in the construction of bridges and in the floors of multi-story buildings.

Types of work during installation of structures

Installation of reinforced concrete structures is mainly a matter for professionals

Installation of metal and reinforced concrete structures is divided into the following types of work:

• Foundation installation;
• Installation of walls in the basement of the building;
• Installation of structural elements of the building frame;
• Installation of ventilation elements and blocks;
• Installation of internal building elements.

Each of these types of work requires adherence to special technology and the use of those steel and reinforced concrete structures that correspond to the assigned tasks.

Initial stage of construction

Before installation, preparatory work should be carried out. Since these structures have considerable weight, it is necessary to consider access to the construction site for vehicles and special equipment (for example, cranes).

Next, geodetic work is carried out to tie the axes of the structure to the terrain. It is also determined which structures and in what quantities should be used. Surveying the area and preliminary calculations allow you to avoid cost overruns and loss of time for reworking incorrectly installed structures.

After transportation to the assembly site, the structures are laid out in the required order. This is a very important and responsible part of the work, because a truss, beam or slab is not a match, and it is very difficult to pull it out from under other structures. The basic rule of layout: if structures are stacked on top of each other, the elements that are installed first should be on top, the bottom row or especially heavy structures should be laid on wooden substrates, free access of equipment to each structure should be provided and the possibility of grasping the part with a crane boom, as well as convenience rafters.

Installation of foundations

The laying and installation of reinforced concrete structures in the pit is carried out according to a pre-drawn diagram, in which the location and order of assembly of all components is precisely marked. Lighthouse blocks are initially laid in the pit. This is the name given to reinforced concrete structures that are located at the corners of the foundation and at the intersections of the axes of the structure.

Monolithic strip foundation

Then cushion blocks are laid, between which technological gaps are left (for example, for passing cables or pipelines). Strip foundation blocks should be located on a sand bed.

Next, the foundation walls and basement floors are installed. The floor panels are welded to the embedded parts in the cushion blocks, and the joints between the panels are filled with cement mortar. Installation of reinforced concrete foundation structures requires constant alignment of the walls with a level, both vertically and horizontally.

Upon completion of installation, an installation horizon is installed - a cement layer along the top of the walls to reach the design mark and level the top edge. After this, the basement is built, and the basement is covered with slabs that form its ceiling and at the same time the floor of the lower floor.

Precast concrete foundations are installed in a slightly different order. First, a slab is laid on the bottom of the pit, onto which the glass block is welded. It is placed on a kind of “bed” consisting of a cement solution. Block foundations are installed by crane, and they are placed in the correct position by weight.

Installation of columns

Before installation, marks indicating the axes are applied to the four sides of the columns, top and bottom. The columns are laid out in front of the installation site in such a way that the crane makes a minimum of movements, and it is convenient for workers to inspect and secure the structures. The column is installed in a glass mounted on the foundation.

• The column is attached to the crane hook in such a way that when lifted it stands vertically;
• The crane places the column in a vertical position. Depending on the weight of the column, different lifting methods are used - rotary, sliding rotation. For stringing columns, friction or pin grips are used;
• Lowering onto the foundation and aligning the position. The column must not be removed from the crane until its correct position has been clearly determined using a level and theodolite.

The column must stand strictly vertically without the slightest tilt. Temporary fastening of the column for its adjustment is carried out using wedge liners.

The next stage is securing the column in the foundation glass. It is produced by injecting concrete mortar into the joints of the column (usually with a pneumatic blower). Once the concrete has reached 50% of its design strength, the wedge liners can be removed. Further work related to the load on the column, as well as the laying of beams, is carried out only after the mixture has completely hardened.

Installation of beams and roof trusses

Reinforced concrete structures

Beams and roof trusses are installed either simultaneously with the roof slabs or separately. Installation of metal and reinforced concrete structures of the main part of the building is carried out depending on the design requirements.

Before installing the trusses, all support areas are aligned and cleaned and axle marks are marked. After this, the structures are delivered to the installation site, slinging and lifting are performed. When placed on a support, the truss or beam is temporarily secured by spacers made of metal pipes, which are attached before lifting begins.

After this, the truss is adjusted and checked for stability and correct installation according to the applied risks. The truss or beam must be positioned so as not to violate the geometry of the building and not to shift relative to the axes of the frame.

Only after a complete check is the element finally secured. The embedded parts are welded to the base plate or column head, as well as to previously installed trusses. The washers of the anchor bolts should also be welded. Only after the beams and trusses are completely installed can they be unfastened.

After the frame is erected, a horizontal stiffening belt is installed, which is a monolithic reinforced concrete beam running along the upper ends of the load-bearing walls. Its task is to ensure the horizontal rigidity of the structure.

Installation of slabs

Like any installation of reinforced concrete structures, installation of slabs requires preliminary preparation. Scaffolding or fencing must be installed on span trusses. There are two main ways of installing slabs - longitudinal and transverse. In the first case, the crane moves along the span, in the second - across the span. Coating slabs are stacked between columns to be delivered to the coating site.

Building a house

The first slab is laid in a place previously marked on the farm, the rest are placed close to it. If the building is framed, the floor slabs are laid after installing the crossbars, purlins and spacer slabs, and if it is frameless, after the walls are built. When laying the slab on the surface, a “bed” is made from the mortar. Excess solution is squeezed out by the plate itself. The first plate must be welded to the truss in four nodes, the subsequent ones in three. Inter-joint seams are sealed with a solution of cement and sand.

Installation of wall panels

Wall panels are installed after the building frame has been erected and the floors have been laid. Before lifting, the panels are grouped into cassettes. With this storage method, the installation of metal and reinforced concrete structures intended for the construction of walls is the most rational. Cassettes can be located between the wall and the tap, behind the tap, as well as in front of it.

The panels are installed by installers only from the inside of the building. Wall panels are placed along the entire height of the building with a section between two columns. Therefore, one cassette must contain such a number of panels to cover the entire area along its entire height.

The panel is accepted by installers at the junction of this structure with the column. To do this, it is necessary to provide workers with access to these points in advance. If there is no transverse overlap, you will have to install cradles, scaffolds or a lift.

The installation of the first row of panels is of particular importance, so their position and compliance with the applied risks is checked especially carefully. External panels perform not only support and protective, but also aesthetic functions. Therefore, the seams between the panels must be sealed not only carefully, but very carefully and not exceed the established standards.

Internal wall panels are installed before the installation of the upper floor slabs. The panels are fastened to the columns with clamps, and to the floor slabs with struts. The final fastening of the wall panels is carried out by welding them to the elements of the building frame.

When installing buildings, structures and technological equipment, cranes are used to deliver elements to their installation site. When installing building structures they use stationary assembly machines that allow work to be carried out in a strictly defined space: assembly booms, assembly masts, chevres (a type of mast), portal hydraulic and cable lifts, screw mast-jib cranes, rigid-legged mast-jib cranes, attached tower cranes. Mobile installation machines are capable of moving from parking lot to parking lot under their own power: crawler, wheeled and tower cranes.

Load-handling devices are shown in Fig. 9.1 and 9.2.

Depending on the height of the structure, there are various methods of installation of structures: by building up, growing, turning with sliding, turning, sliding, etc. The sequence of installing elements in the design position determines the following installation methods: element-by-element, differentiated, complex and mixed. Installation of structures can be carried out from an object warehouse or directly from vehicles (“installation from wheels”). For the installation of pipelines from individual pipes or their short sections, self-propelled jib cranes are used on caterpillar, automobile and pneumatic wheels. For the installation of pipes from long sections and strings, the main machines are pipe-laying cranes with a side boom and a folding counterweight.

Selection of assembly cranes. The selection of a tap is usually carried out in two stages. At the first stage, the minimum possible operating parameters of the crane required for the given conditions and accepted installation work schemes are determined - hook reach, lifting height (depth of lowering into the trench) of the hook and lifting capacity. At the second stage, technical and economic indicators are calculated for each of the selected cranes and the most economical one is determined from them.

Rice. 9.1.1 - carabiner;

• 2- hook; 3- traverse; 4 - cable; 5- electric grip; 6- thimble;
• 7 - lightweight sling; 8- universal sling; 9- linings;
• 10- column; 11 - suspension; 12- grip cheeks; 13- frame;
• 14- lever; 15- movable shaft; 16- pressing shoes;
• 17- safety chains

Calculation of operating parameters for selecting a crane. First, the minimum hook reach is determined - the smallest distance from the axis of rotation of the crane's turntable (for pipe-laying cranes - from the outer caterpillar) to the axis of the pipeline in the trench. The required reach of the hook T to the installation crane, depending on the adopted pipeline installation scheme (Fig. 9.3), can be determined using the following formulas and dependencies.

When laying pipelines from single pipes in trapezoidal trenches according to the scheme shown in Fig. 9.3, A, b k = 0,5(b + B cr) + 1.2 tk, Where b- width of the trench along the bottom, m; B cr - crane base width, m; 1.2 TI - the distance from the base of the excavation slope to the tracks (wheels or outriggers) of the crane (the free berm must be at least 1 m); T- laying slopes; /? - trench depth, m.

Rice. 9.2. Load-handling devices used in the construction of pipelines: a - slinging of pipes with a universal sling with a device for slinging; b - semi-automatic lanyard “noose”; V - slinging the pipe with this sling; g, d- two- and four-leg slings with end grips for pipes; e - slinging a steel pipe with a two-legged sling; and - articulated end grip for asbestos-cement pipes; h- mounting bracket for reinforced concrete pipes; And - the same for ceramic ones; 1 - cable; 2- latch-lock; 3- cheeks; 4- base plate;

• 5 - finger; 6 - cable (sling); 7 - pipe; 8 - bracket; 9 - capture; 10 - thimble; 11 - earring; 12- soft pads; 13- suspension device;
• 14 - mounting bracket

When installing pipelines from single pipes in rectangular trenches with fasteners (Fig. 9.3, b), the hook extension is determined in a similar way.

For the installation of pipelines from large assembly blanks (up to 18-24 m in length), the hook extension is taken as minimal as possible, but so that the operating conditions of the crane are most favorable (Fig. 9.3, c), b k = 0,5b + 1,2 tk + s1 n + 1 + 0.5B cr, where With! And - the outer diameter of the pipes being laid, and for socket pipes - the diameter of the socket, m.

In deep trenches, as well as in soft soils, pipes are laid with a large hook reach. Moreover, if the distance from the axis of rotation of the crane to the center of gravity of the pipe section is less than the hook reach required by calculation (b 2 then the installation diagram is left the same (Fig. 9.3, V), and if Ts >b K, then the crane is moved away from the section to the side at a distance of at least 1 m and moved forward by an amount b 2 -b k, further carrying out installation at the estimated hook reach (determined by the above formula). During the installation process, in this case, guy ropes are applied to the ends of the pipe section to prevent it from turning during lifting. When such a displacement is impossible due to local or other conditions, the installation is carried out and the crane is selected with a hook extension equal to b 2 b K = b 2 = 0.5 4r. s + 1.5 + / gab, where / trs is the length of the pipe section; 1.5 m - the clear distance between the end of the section and the overall dimensions of the crane (according to safety conditions); 4.6 - the distance between the axis of rotation of the crane platform and the front edge of its chassis.

When installing pipes from vehicles (Fig. 9.3, G) The hook extension is determined using a formula similar to the one given above and checked according to the condition: b^=/)+ 1 + B a, where D. r is the distance between the axes of movement of the crane and vehicles; /) - radius of rotation of the tail part of the crane platform; B a - width of the vehicle base.

This simultaneously determines the installation location of the vehicles in relation to the crane. Distance between the axis of rotation of the crane and the center of gravity of the delivered pipe (section) (b rp):

Laying of insulated braided steel pipelines in the field is usually carried out using pipe-laying cranes. Based on the condition of preventing the collapse of the trench wall, the distance from the edge to the pipe-laying crane must be at least 2 m. The required hook reach of the pipe-laying crane b K -0.5b + tI + 2 m.

If the laying of isolated strands is carried out using jib cranes on caterpillar or pneumatic wheels, then they are placed on the other side of the strand (counting from the trench), and the required reach is then b k = 0,5b + mI + 4„1 + With! and +/ br2 + 0.5B cr, where / br1, / br2 are, respectively, the distance from the edge of the trench to the pipe string and from it to the tap. Usually they take /brb = 1 m, and /br2 = 0.5-1 m.

Crane capacity calculated based on the maximum load that the crane must lift with the required hook reach b k.

It is determined by the mass of the installed pipes or their sections and strands, taking into account the mass of load-handling devices. Using reference books, the appropriate types and brands of cranes are selected. When two cranes are operating, calculations are carried out on one of them. The main technical and economic indicators are: duration and complexity of installation; cost of installation work per unit of structure.

Rice. 9.3. Scheme for determining the hook extension when laying pipes: a - laying single pipes in trapezoidal trenches; b - the same in trenches with fastenings; V - the same for links longer than 12 m;

d- when installing “from wheels”

The selection of lifting devices (slings, grips, brackets, traverses, suspensions, etc.) for lifting, moving and laying pipes is carried out based on the fact that they meet the following basic requirements: ensuring the necessary load capacity; strength; reliable fastening (slinging) of the pipe; inadmissibility of damage to both the pipe itself and its insulating coating; simplicity of design and use.