Airfield slabs GOST 25912.0 91

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STATE STANDARD OF THE USSR UNION

REINFORCED CONCRETE PLATES
PRE-STRESSED PAG
FOR AIRPORT COVERINGS

Specifications

STATE CONSTRUCTION COMMITTEE OF THE USSR

Moscow

STATE STANDARD OF THE USSR UNION

Date of introduction 01/01/92

This standard applies to prestressed reinforced concrete slabs PAG with dimensions of 6´2 m, made of heavy concrete and intended for the construction of prefabricated airfield pavements.

1. TECHNICAL REQUIREMENTS

1.1. The slabs are manufactured in accordance with the requirements of this standard and approved by in the prescribed manner technological documentation containing requirements for the manufacture of slabs at all stages production process, according to the drawings given in GOST 25912.1 - GOST 25912.3.

1.2. The slabs must be manufactured in forms that ensure compliance with the requirements for the quality and accuracy of slab manufacturing established by this standard.

1.3. Main parameters and dimensions

1.3.1. Depending on the thickness, the slabs are divided into PAG-14, PAG-18 and PAG-20.

1.3.2. The shape and main dimensions of the slabs must correspond to those indicated in the drawing. 14.

Notes:

1. On the longitudinal edges of the slabs, it is allowed to install recesses with dimensions of 20´100´200 mm to ensure the possibility of lifting the slabs using automatic grippers.

2. In slabs with inclined longitudinal edges, mounting and butt products M1 or M3 (drawings 1 and 3) are installed flush with the plane defining overall size slab width - 2000 mm.

PAG-14 plate

Plates PAG-18 and PAG-20

Options for the profile of the longitudinal edges of the slab (sections 6 - 6)

t- slab thickness

The size for the PAG-14 slab is indicated in brackets

1 - assembly and butt product M1 or M3; t- slab thickness

1 - butt product M2 or M4; 2 - butt product M4a

1.3.3. By agreement with the consumer, it is allowed to manufacture slabs with a profile of longitudinal edges that differ from those shown in the diagram. 2 (sections 6 - 6), with dimensions of openings for assembly-butt products that differ from those shown in Fig. 1 and 3, and with assembly-butt products of a different design, provided that the operational properties of the airfield pavement are ensured.

In PAG-18 slabs, the distance from the end of the slab to the assembly and joint products, as agreed with the consumer, is allowed to be less than 1500 mm.

1.3.4. The slabs are made with the working surface (the upper surface of the airfield pavement) facing up. It is allowed, by agreement with the consumer, to manufacture slabs with the working surface down.

1 - corrugation work surface slabs

The working surface of slabs made with this “up” surface must be rough. The surface roughness is obtained by treating this surface with nylon brushes or tarpaulin tape (after compaction concrete mixture).

The working surface of slabs manufactured with this surface “down” must have corrugation. The corrugated surface is formed by using a form of steel sheet with rhombic corrugation as the bottom of the pallet in accordance with GOST 8568. The sheet on the pallet is positioned so that the large diagonal of the rhombus is perpendicular to the longitudinal axis of the slab (Fig. 5).

The depth of the corrugation must be at least 1.5 mm. By agreement with the consumer, it is allowed to produce slabs with a corrugation depth of 1.2 mm.

1.3.5. Reinforcement of slabs is carried out:

in the longitudinal direction - with prestressed reinforcement;

in the transverse direction - with non-tensioned reinforcement.

1.3.6. As prestressing reinforcement for slabs, bar reinforcing steel of classes At-V, A-V, At-IV, At-IVC and A-IV is used. Prestressed reinforcement should be used in the form of whole bars without joints.

Non-prestressing reinforcement is made from rod reinforcing steel of classes A-III, At-IIIC, A-II and reinforcing wire of class BP-1.

1.3.7. The design of the plates is given:

1.3.8. The slabs are designated by marks consisting of alphanumeric groups separated by a hyphen.

The first group contains the abbreviated letter name of the slab - PAG (smooth airfield slab).

In the second group, the thickness of the slab in centimeters and the characteristics of the prestressed longitudinal reinforcement are given:

IV - for reinforcing steel of classes At-IV, At-IVC and A-IV;

V - for reinforcing steel of classes At-V and A-V.

In the designation of the brand of slabs PAG-14 with prestressed longitudinal reinforcement with a diameter of 12 mm (GOST 25912.1), the number 1 (separated by a hyphen) is additionally given.

Examples symbol slabs:

18 cm thick with prestressed longitudinal reinforcement class At-V:

PAG-18U,

14 cm thick with prestressed reinforcement class At-IVC with a diameter of 12 mm:

PAG-14IV-1.

1.4. Concrete requirements

1.4.1. Slabs should be made of heavy concrete medium density more than 2200 to 2500 kg/m 3 inclusive, meeting the requirements of GOST 26633.

1.4.2. The actual strength of concrete must correspond to the required strength, assigned according to GOST 18105, depending on the standardized strength of concrete (class of tensile strength in bending and class of compressive strength, transfer and tempering strength) and on the characteristics of the actual uniformity of concrete strength.

1.4.3. The slabs must be made of concrete with tensile bending strength class B btb 3.6 and compressive strength class B25. In this case, the actual compressive strength of concrete (clause 1.4.2) should not be lower than 29.4 MPa (300 kgf/cm2).

1.4.4. The normalized transfer strength of concrete is 70% of the concrete class for compressive strength.

1.4.5. The value of the normalized tempering strength of concrete is taken equal to the value of the normalized transfer strength and not lower than 70% of the concrete class for tensile strength in bending.

The supply of slabs with a concrete tempering strength lower than the strength corresponding to its class in terms of tensile strength in bending and class in terms of compressive strength is carried out provided that the manufacturer guarantees that the concrete structure achieves the required strength, determined by the results of testing control samples made from the worker’s concrete mixture composition, stored under conditions in accordance with GOST 18105 and tested at the age of 28 days (GOST 13015.0).

1.4.6. The frost resistance of the concrete of the slabs must correspond to the frost resistance grade of concrete specified in the order of the slabs specified in the design documentation of a particular structure.

The frost resistance grade of concrete is accepted for slabs intended for use in areas with an estimated average monthly air temperature of the coldest month (according to SNiP 2.01.01) not lower than:

up to minus 5 °C incl. - F100;

below minus 5 °C to minus 15 °C inclusive. - F150;

below minus 15 °C - F200.

1.4.7. The concrete mixture used to make slabs must have a water-cement ratio of no more than 0.5.

In a compacted concrete mixture, the volume of entrained air (when using air-entraining additives) should be within 5 - 6%.

1.4.8. To regulate and improve the properties of the concrete mixture and concrete in the manufacture of slabs, plasticizing and air-entraining (gas-forming) chemical additives should be used in accordance with GOST 24211.

1.4.9. The quality of materials used to prepare concrete must ensure compliance technical requirements, established by this standard for concrete slabs.

1.4.10. Portland cement in accordance with GOST 10178, intended for concrete airfield pavements, should be used as a binder.

1.4.11. Coarse and fine aggregates - according to GOST 10268 (grain size of coarse aggregate - no more than 20 mm).

The use of gravel as a coarse aggregate is permitted by agreement with the consumer with an appropriate feasibility study.

1.4.12. Plasticizing and air-entraining (gas-forming) chemical additives used in the preparation of concrete must meet the requirements of regulatory and technical documentation approved in the prescribed manner.

1.5. Requirements for reinforcement and assembly-butt products

1.5.1. The shape and dimensions of reinforcement and assembly-butt products must correspond to those given in GOST 25912.4.

1.5.2. Welded reinforcement and assembly-butt products must meet the requirements of GOST 10922.

1.5.3. Grades of reinforcing steel of classes A-III, A-II and A-I, as well as grades of carbon steel of ordinary quality used for the manufacture of assembly-butt products must correspond to the grades established project documentation specific structure or specified when ordering slabs.

1.5.4. Reinforcing steel must meet the requirements:

rod reinforcing steel classes:

reinforcing wire class VR-1 - GOST 6727.

1.6. Tension of prestressing reinforcement

1.6.1. Tension of the prestressed longitudinal reinforcement of the slab should be carried out mechanically or electrothermally.

1.6.2. The heating temperature of prestressed reinforcement using the electrothermal method of tensioning it should not exceed 450 °C.

1.6.3. Stress values ​​in the prestressing reinforcement, controlled after its tensioning on the stops, for reinforcing steel classes:

At-V and A-V - 590 MPa (6000 kgf/cm 2);

At-IV, At-IVС and A-IV - 530 MPa (5400 kgf/cm 2).

Deviations in stress values ​​in prestressed reinforcement should not exceed ±10%.

1.7. Materials used to lubricate molds should not cause harmful effects on concrete.

Mold release agent should be applied thin layer evenly over the entire surface of the mold tray, removing excess lubricant that has formed in certain places.

1.8. When making slabs, the concrete mixture is placed in a mold with the working surface down (clause 1.3.4) when the temperature difference between the mold tray and the concrete mixture is no more than 20 °C.

The working surface of the slabs made with this surface “up”, leveled after compacting the concrete mixture, is treated with nylon brushes or tarpaulin tape, cleared of hardened cement mortar. Before heat and humidity treatment of slabs, their specified surface must be covered with burlap, plastic film, bituminized paper or other similar materials.

1.9. The mode of heat treatment of the slabs must correspond to that established by the technological documentation in accordance with the instructions of SNiP 3.09.01.

The isothermal heating temperature should not exceed 70 °C.

The relative humidity of the environment during the period of isothermal heating of slabs in pit-type chambers must be at least 98%; in tunnel-type chambers - not lower than 96%.

1.10. The transfer of compression force to concrete (tension release of prestressing reinforcement) should be carried out after the concrete slab reaches the required transfer strength (clause 1.4.2).

1.11. Requirements for the accuracy of plate manufacturing.

1.11.1. Actual deviations geometric parameters slabs should not exceed the limits specified in the table. 1.

Table 1

along the length ±5;

thickness +3;

from the flatness of the working surface 4.

1.11.2. Actual deviations of the thickness of the protective layer of concrete before the reinforcement from its nominal value indicated in the drawings should not exceed ±3 mm.

1.11.3. The ends of the prestressing reinforcement should not protrude beyond the end surfaces of the slabs by more than 5 mm.

1.12. Requirements for the quality of surfaces and appearance of slabs

1.12.1. The working surface of the slabs (clause 1.3.4) should not have cracks.

Shrinkage and technological cracks with a width of more than 0.05 mm and a length of more than 50 mm are not allowed on the non-working surface and side edges of the slabs.

The corrugated surface of the slab should have a clear corrugation pattern without trenches on the edges of the grooves.

1.12.2. Peeling of concrete is not allowed on the working surface of the slabs.

1.12.3. The dimensions of cavities, local sagging and depressions on the concrete surface and around the concrete edges of the slabs should not exceed the values ​​​​indicated in the table. 2.

table 2

1.12.4. Correcting defects on the working surface and sealing around the ribs of the slabs is not allowed.

1.12.5. The side faces of the lower and upper surfaces of the slabs, as well as the open surfaces of the assembly and joint products must be cleared of concrete deposits.

1.13. Marking

1.13.1. Marking of slabs must comply with the requirements of GOST 13015.2 and this standard.

1.13.2. Markings are applied on the side longitudinal edge of the slab.

Markings must contain:

brand of slab (clause 1.3.8);

trademark or short name of the manufacturer;

technical control stamp;

date of manufacture of the slab.

1.13.3. On the longitudinal edges of the slab, at a distance of 1 m from the end, an installation sign “Location of support” is applied.

1.13.4. The manufacturer's mark must be applied to the working surface of the slab, the designation and method of application of which is agreed upon with the customer and specified in the contract for the supply of slabs.

2. ACCEPTANCE

2.1. Acceptance of slabs is carried out in batches in accordance with the requirements of GOST 13015.1 and this standard.

The batch includes slabs of the same type, manufactured by the enterprise using the same technology from materials of the same type and quality within no more than one day.

The batch volume should not exceed 200 pcs.

2.2. Acceptance of slabs is carried out according to the results:

acceptance tests - in terms of concrete strength indicators (classes of tensile strength in bending and compressive strength, transfer and tempering strength), water-cement ratio of the concrete mixture, compliance of reinforcement and assembly-butt products, thickness of the protective layer of concrete to the reinforcement, accuracy of geometric parameters , surface quality and appearance slabs, according to the crack resistance of the lower and upper zones of the slab;

periodic tests - in terms of frost resistance of concrete, in terms of the volume of entrained air in the compacted concrete mixture.

2.3. A batch of slabs in terms of their strength and rigidity is accepted if the requirements established by this standard for a set of standardized and design indicators characterizing the strength of concrete, the thickness of the slab, the diameter and location of the reinforcement, the thickness of the protective layer of concrete to the reinforcement, the main parameters of reinforcement and assembly-butt products are met. , tension of prestressing reinforcement, physical and mechanical properties reinforcing steel, which are checked during the process of incoming, operational and acceptance control in accordance with GOST 13015.1.

2.4. Acceptance control of concrete strength (based on the results of testing concrete samples or non-destructive methods) is carried out in accordance with GOST 18105.

Determination of the tensile strength of concrete in bending, as well as the compressive strength of concrete at the design age (clause 1.4.3) is carried out only from samples.

2.4.1. To control the transfer and tempering compressive strength of concrete non-destructive methods Three slabs are selected from the batch.

Concrete strength control is carried out in five sections of any slab surface - one in the middle of the slab and in each corner at a distance of 30 - 40 cm from its top along a bisector.

2.4.2. In cases where, during inspection, it is established that the tempering strength of the concrete slabs does not meet the requirements specified in clause 1.4.5, delivery of such slabs to the consumer should be made only after the concrete slabs have achieved strength corresponding to the classes of tensile strength in bending and strength for compression (clause 1.4.3).

2.5. Periodic testing based on the frost resistance of concrete slabs, as well as on the volume of entrained air in the compacted concrete mixture, it is carried out at least once every 6 months, as well as when the slab manufacturing technology changes, starting materials and the composition of the concrete mixture used to prepare concrete.

2.6. The water-cement ratio in the concrete mixture is monitored for each batch of concrete slabs.

2.7. Acceptance of reinforcement and assembly-butt products is carried out before installing them in the mold in accordance with GOST 10922 and GOST 23858.

2.8. Acceptance of slabs in terms of accuracy of geometric parameters, thickness of the protective layer of concrete to reinforcement, surface quality, controlled by measurements, should be carried out based on the results of selective one-stage control.

Acceptance of slabs based on the presence of assembly and joint products, cleaning of their open surfaces and slab edges from concrete deposits, the presence of concrete peeling and grease stains on the working surface of the slab, and the correct application of markings and signs is carried out based on the results of continuous inspection.

2.9. When accepting slabs based on the crack resistance of their lower and upper zones, one slab is selected for testing from each batch of slabs, which satisfies the requirements of this standard in other respects.

It is allowed to use for testing a slab that has cavities, local sagging and chips of concrete, the dimensions of which exceed those allowed by this standard (clause 1.12.3) by no more than twice, and other defects that do not affect the strength of the slabs.

The slab is considered to have passed the test if, under the control load specified in clause 3.8.4, no cracks are detected on the surface of the test zone and side edges upon careful inspection through a magnifying glass with fourfold magnification.

If the results of the crack resistance test in at least one zone are unsatisfactory, an additional test of two slabs of this batch is carried out. If at least one of two slabs does not pass the test, then all slabs in this batch are tested.

By agreement with the consumer, testing of slabs for crack resistance may be carried out not from each batch, but from a larger number of slabs and at other times depending on the volume of their production, but at least once a month.

2.10. Based on the acceptance results, a document is drawn up on the quality of the supplied slabs in accordance with GOST 13015.3.

Additionally, the quality document must contain:

concrete grade for frost resistance;

class of reinforcing steel used as longitudinal prestressing reinforcement (At-V, A-V, At-IVC, At-IV, A-IV);

grades of reinforcing steel of classes A-I - A-III and grades of carbon steel of ordinary quality, from which assembly and butt plate products are made.

3. CONTROL METHODS

3.1. The strength of concrete, when tested by samples, is determined according to GOST 10180 on a series of samples made from a concrete mixture of the working composition and stored under conditions in accordance with GOST 10105.

Determination of the actual transfer and tempering compressive strength of concrete when monitoring them using non-destructive methods in slabs (clause 2.4.) is carried out using the ultrasonic method in accordance with GOST 17624, using instruments mechanical action or by the tear-off method with chipping according to GOST 22690.

3.2. Frost resistance of concrete slabs should be determined in accordance with GOST 10060 for concrete airfield pavements .

3.3. The standardized quality indicators of the concrete mixture are checked according to GOST 10181.0 - GOST 10181.4.

3.4. Methods for monitoring reinforcement and assembly-butt products - according to GOST 10922 and GOST 23858.

3.5. Methods for controlling the raw materials used to manufacture boards must comply with established standards or specifications for these materials.

3.6. Measurement of controlled stress in prestressed longitudinal reinforcement - according to GOST 22362.

3.7. Dimensions, deviations from profile straightness, from slab flatness, from perpendicularity adjacent faces, the thickness of the protective layer of concrete to the reinforcement, the position of the assembly and butt products, as well as the quality concrete surfaces and the appearance of the slabs is checked by the methods established by GOST 26433.0 and GOST 26433.1.

3.8. Control of crack resistance of slabs

Scheme A

Scheme B

1 - test plate; wooden beams cross section 10´10 cm; 4 - loading ballast

Note. Dimensions in brackets refer to testing schemes for PAG-18 and PAG-20 slabs.

3.8.1. Testing of slabs for crack resistance of the lower zone should be carried out according to scheme A shown in Fig. 6. Testing of slabs for crack resistance of the upper zone is carried out according to scheme A or B, shown in Fig. 6.

3.8.2. Testing of slabs after heat treatment (with the tempering strength of concrete) should be carried out no earlier than 4 hours and no later than 2 days.

3.8.3. First, the slab is tested for the crack resistance of the lower zone, and then the same slab is tested for the crack resistance of the upper zone. When testing the slab for crack resistance of the upper zone according to scheme A shown in Fig. 6, the slab is turned over after testing the lower zone.

The loading of the slab during testing is carried out in stages. The load share of each stage should be no more than 10% of the reference load, and the last two stages should be no more than 5%.

After applying each stage of the control load, the slab is kept under load for at least 10 minutes, and after applying the full control load - for at least 30 minutes.

3.8.4. The values ​​of the control load for testing the crack resistance of the slab are given in table. 3.

Table3

4. TRANSPORTATION AND STORAGE

4.1. Transportation and storage of slabs should be carried out in accordance with the requirements of GOST 13015.4 and this standard.

4.2. The slabs should be transported and stored in a horizontal position.

UDC 691.328-41:006.354 ZhZZ Group

STATE STANDARD OF THE USSR UNION

REINFORCED CONCRETE LLITS PRESTRESSED PAG FOR AERODROME

COATINGS Technical specifications

Reinforced concrete prestressed slabs PAG for aerodrome pavement.

Date of introduction 01/01/92

This standard applies to prestressed reinforced concrete slabs PAG with dimensions of 6X2 m, made of heavy concrete and intended for the construction of prefabricated airfield pavements.

1. TECHNICAL REQUIREMENTS

1.1. The slabs are manufactured in accordance with the requirements of this standard and duly approved technological documentation containing the requirements for the manufacture of slabs at all stages of the production process, according to the drawings given in GOST 25912.1 - GOST 25912.3.

1.2. The slabs must be manufactured in forms that ensure compliance with the requirements for the quality and accuracy of slab manufacturing established by this standard.

1.3. Main parameters and dimensions

1.3.1. Depending on the thickness, the slabs are divided into PAG-14, PAG-18 and PAG-20.

1.3.2. The shape and main dimensions of the slabs must correspond to those indicated in the drawing. 1-4.

Notes:

1. On the longitudinal edges of the slabs, it is allowed to install recesses with dimensions of 20x10x2x0 mm to ensure the possibility of lifting the slabs using automatic grippers.

2. In slabs with inclined longitudinal edges, mounting and butt products Ml or M3 (drawings 1 and 3) are installed flush with the plane that determines the overall dimension of the slab width - 2000 mm.

Official publication ★ ★

© Standards Publishing House, 1991

This standard cannot be reproduced, replicated or distributed in whole or in part without permission from the USSR State Standard.

Plate G1A G-14

ki

PA G-18 slabs

Options for the profile of the longitudinal edges of the slab (sections, 6-6)

The size for the PAG-14 slab is indicated in brackets

/ - mounting and butt product Ml or M3; / - slab thickness

In parenthesis to the pa is indicated for the plate PA g-no.

I - butt product M2 or M4; 2 - butt product M4a

1.3.3. By agreement with the consumer, it is allowed to manufacture slabs with a profile of longitudinal edges that differ from those shown in the diagram. 2 (section 6-6), with opening sizes for assembly and butt products that differ from those shown in Fig. 1 and 3, and with assembly-butt products of a different design, provided that the operational properties of the airfield pavement are ensured.

In PAG-18 slabs, the distance from the end of the slab to the assembly and butt products, as agreed with the consumer, is allowed to be less than 1500 mm.

1.3.4. The slabs are made with the working surface (the upper surface of the airfield pavement) facing up. It is allowed, by agreement with the consumer, to manufacture slabs with the working surface down.

/ - corrugation of the working surface of the plate

The working surface of slabs made with this “up” surface must be rough. The surface roughness is obtained by treating this surface with nylon brushes or tarpaulin tape (after compacting the concrete mixture).

The working surface of slabs manufactured with this surface “down” must have corrugation. The corrugated surface is formed by using a steel sheet with rhombic corrugation in accordance with GOST 8568 as the bottom of the pallet. The sheet on the pallet is positioned so that the large diagonal of the rhombus is perpendicular to the longitudinal axis of the plate (Fig. 5).

The depth of the corrugation must be at least 1.5 mm. By agreement with the consumer, it is allowed to produce slabs with a corrugation depth of 1.2 mm.

1.3.5. Reinforcement of slabs is carried out:

in the longitudinal direction - with prestressed reinforcement;

in the transverse direction - with non-tensioned reinforcement.

1.3.6. Bar reinforcing steel of classes At-V, A-V, At-IV, At-TVC and A-IV is used as prestressing reinforcement for slabs. Prestressed reinforcement should be used in the form of whole bars without joints.

Non-prestressing reinforcement - from rod reinforcing steel of classes A-III, At-ShS, A-P and reinforcing wire of class BP-b

1.3.7. The design of the plates is given:

PAG-14 - in GOST 25912.1;

PLG-18 - in GOST 25912.2;

PAG-20 - in GOST 25912.3.

1.3.8. The slabs are designated by marks consisting of alphanumeric groups separated by a hyphen.

The first group contains the abbreviated letter name of the slab - G1AG (smooth airfield slab).

In the second group, the thickness of the slab in centimeters and the characteristics of the prestressed longitudinal reinforcement are given:

IV - for reinforcing steel of classes At-IV, At-IVC and A-IV;

V -- for reinforcing steel of classes At-V and A-V.

In the designation of the brand of slabs PAG-14 with prestressed longitudinal reinforcement with a diameter of 12 mm (GOST 25912.1), the number 1 (separated by a hyphen) is additionally given.

Examples of tile symbols

18 cm thick with prestressed longitudinal reinforcement class At-V:

14 cm thick with prestressed reinforcement of class At-IVC with a diameter of 12 mm:

1.4. Concrete requirements

1.4.1. The slabs should be made from heavy concrete with an average density of more than 2200 to 2500 kg/m 3 inclusive, meeting the requirements of GOST 26633.

1.4.2. The actual strength of concrete must correspond to the required strength, assigned according to GOST 18105, depending on the standardized strength of concrete (class of tensile strength in bending and class of compressive strength, transfer and tempering strength) and on the characteristics of the actual uniformity of concrete strength.

1.4.3. The slabs must be made of concrete with a tensile bending strength class B^b 3.6 and a compressive strength class B25. In this case, the actual compressive strength of concrete (clause 1.4.2) should not be lower than 29.4 MPa (300 kgf/cm2).

1.4.4. The normalized transfer strength of concrete is 70% of the concrete class for compressive strength.

1.4.5. The value of the normalized tempering strength of concrete is taken equal to the value of the normalized transfer strength and not lower than 70% of the concrete class for tensile strength in bending.

The supply of slabs with a concrete tempering strength lower than the strength corresponding to its class for tensile strength in bending and class for compressive strength is carried out on the condition that

if the manufacturer guarantees that the concrete structure achieves the required strength, determined by the results of testing control samples made from a concrete mixture of the working composition, stored under conditions in accordance with GOST 18105 and tested at the age of 28 days (GOST 13015.0).

1.4.6. The frost resistance of the concrete of the slabs must correspond to the frost resistance grade of concrete specified in the order of the slabs specified in the design documentation of a particular structure.

The frost resistance grade of concrete is accepted for slabs intended for use in areas with an estimated average monthly air temperature of the coldest month (according to SNiP 2.01.01) not lower than:

up to minus 5 °C incl. - F100;

below minus 5°С to minus 15°С inclusive. - F150;

below minus 15 °C - F200.

1.4.7. The concrete mixture used to make slabs must have a water-cement ratio of no more than 0.5.

In a compacted concrete mixture, the volume of entrained air (when using air-entraining additives) should be within 5-6%

1.4.8. To regulate and improve the properties of the concrete mixture and concrete in the manufacture of slabs, plasticizing and air-entraining (gas-forming) chemical additives should be used in accordance with GOST 24211.

1.4.9. The quality of materials used to prepare concrete must ensure compliance with the technical requirements established by this standard for concrete slabs.

1.4.10. Portland cement in accordance with GOST 10178, intended for concrete airfield pavements, should be used as a binder.

1.4.11. Coarse and fine aggregates - according to GOST 10268 (grain size of coarse aggregate - no more than 20 mm).

The use of gravel as a coarse aggregate is permitted by agreement with the consumer with an appropriate feasibility study.

1.4.12. Plasticizing and air-entraining (gas-forming) chemical additives used in the preparation of concrete must meet the requirements of regulatory and technical documentation approved in the prescribed manner.

Water - according to GOST 23732.

1.5. Requirements for reinforcement and assembly butt products

1.5.1. The shape and dimensions of reinforcement and assembly-butt products must correspond to those given in GOST 25912.4.

1.5.2. Welded reinforcement and assembly-butt products must meet the requirements of GOST 10922.

1.5.3. Reinforcing steel grades classes A-Sh, A-P and A-1> as well as grades of carbon steel of ordinary quality used for the manufacture of assembly-butt products must correspond to the grades established by the design documentation of a particular structure or specified when ordering slabs.

1.5.4. Reinforcing steel must meet the requirements:

rod reinforcing steel classes:

At-V, At-IVC, At-IV and At-IIIC - GOST 10884;

A-V, A-IV, A-Sh, A-P and A-I - GOST 5781;

reinforcing wire class VR-1 - GOST 6727.

1.6. Tension of prestressing reinforcement

1.6.1. Tension of the prestressed longitudinal reinforcement of the slab should be carried out mechanically or electrothermally.

1.6.2. The heating temperature of prestressed reinforcement using the electrothermal method of tensioning it should not exceed 450 °C.

1.6.3. Stress values ​​in the prestressing reinforcement, controlled after its tensioning on the stops, for reinforcing steel classes:

At-V and A-V - 590 MPa (6000 kgf/cm 2);

At-IV, At-IVC and A-IV - 530 MPa (5400 kgf/cm 2).

Deviations in stress values ​​in prestressed reinforcement should not exceed ±10%.

1.7. The materials used to lubricate the molds should not have a harmful effect on the concrete.

Mold lubricant should be applied in a thin layer evenly over the entire surface of the mold tray, removing excess lubricant that has formed in some places.

1.8. When making slabs, the concrete mixture is placed in a mold with the working surface down (clause 1.3.4) when the temperature difference between the mold tray and the concrete mixture is no more than 20 °C.

The working surface of the slabs made with this surface “up”, leveled after compacting the concrete mixture, is treated with nylon brushes or tarpaulin tape, cleared of hardened cement mortar. Before heat and humidity treatment of the slabs, their specified surface must be covered with burlap, plastic film, bituminized paper or other similar materials.

1.9. The mode of heat treatment of the slabs must correspond to that established by the technological documentation in accordance with the instructions of SNiP 3.09.01.

The isothermal heating temperature should not exceed 70 °C.

Relative humidity of the environment during the isothermal period

heating of slabs in pit-type chambers should be at least 98%; in tunnel-type chambers - not lower than 96%.

1.10. The transfer of compression force to concrete (tension release of prestressing reinforcement) should be carried out after the concrete slab reaches the required transfer strength (clause 1.4.2).

1.11. Requirements for the accuracy of plate manufacturing

1.11.1. Actual deviations of the geometric parameters of the slabs should not exceed the limits indicated in table L

Table 1

The dimensions of the slabs in millimeters should not exceed: length ±5; thickness +3;

from the flatness of the working surface 4.

1.11.2, Actual deviations of the thickness of the protective layer of concrete before the reinforcement from its nominal value indicated in the drawings should not exceed ±3 mm.

1.11.3. The ends of the prestressing reinforcement should not protrude beyond the end surfaces of the slabs by more than 5 mm.

1.12. Requirements for the quality of surfaces and appearance of slabs

1.12.1. The working surface of the slabs (clause 1.3.4) should not have cracks.

On the non-working surface on the side faces of the slabs, shrinkage and technological cracks with a width of more than 0*05 mm and a length of more than 50 mm are not allowed.

The corrugated surface of the slab must have a clear corrugation pattern without edges around the edges of the grooves.

1.12.2. Peeling of concrete is not allowed on the working surface of the slabs.

1.12.3. The dimensions of cavities, local sagging and depressions on the concrete surface and around the concrete edges of the slabs should not exceed the values ​​​​indicated in the table. 2.

table 2

1.12.4. Correcting defects on the working surface and sealing around the ribs of the slabs is not allowed.

1.12.5. The side faces of the lower and upper surfaces of the slabs, as well as the open surfaces of the assembly and joint products, must be cleared of concrete deposits.

1.13. Marking

1.13.1. Marking of slabs must comply with the requirements of GOST 13015.2 and this standard.

1.13.2. Markings are applied on the side longitudinal edge of the slab.

Markings must contain;

brand of slab (clause 1.3.8);

trademark or short name of the manufacturer;

technical control stamp;

date of manufacture of the slab.

1.13.3. On the longitudinal edges of the slab, at a distance of 1 m from its end, an installation mark “Location of support” is applied.

1.13.4. The manufacturer's mark must be applied to the working surface of the slab, the designation and method of application of which is agreed upon with the customer and specified in the contract for the supply of slabs.

2. ACCEPTANCE

2.1. Acceptance of slabs is carried out in batches in accordance with the requirements of GOST 13015.1 and this standard.

The batch includes slabs of the same type, manufactured by the enterprise using the same technology from materials of the same type and quality within no more than one day.

The batch volume should not exceed 200 pcs.

2.2. Acceptance of slabs is carried out according to the results:

acceptance tests - in terms of concrete strength indicators (classes of tensile strength in bending and compressive strength, transfer and tempering strength), water-cement ratio of the concrete mixture, compliance of reinforcement and installation-butt products, thickness of the protective layer of concrete to the reinforcement, accuracy of geometric parameters , surface quality and appearance of the slabs, crack resistance of the lower and upper zones of the slab;

periodic tests - in terms of frost resistance of concrete, in terms of the volume of entrained air in the compacted concrete mixture.

2.3. A batch of slabs in terms of their strength and rigidity is accepted if the requirements established by this standard for a set of standardized and design indicators characterizing the strength of concrete, the thickness of the slab, the diameter and location of the reinforcement, the thickness of the protective layer of concrete before the reinforcement, the main parameters of reinforcement and assembly joint products, the tension of the prestressing reinforcement, physical and mechanical properties of reinforcing steel, which are checked during the process of incoming, operational and acceptance control in accordance with GOST 13015.1.

2.4. Acceptance control of concrete strength (based on the results of testing concrete samples or non-destructive methods) is carried out in accordance with GOST 18105.

Determination of the tensile strength of concrete in bending, as well as the compressive strength of concrete at the design age (clause 1.4.3) is carried out only from samples.

2.4.1. To control the transfer and tempering strength of concrete in compression using non-destructive methods, three slabs are selected from the batch.

Concrete strength control is carried out in five sections of any slab surface - one in the middle of the slab and in each corner at a distance of 30-40 cm from its top along a bisector.

2.4.2. In cases where, during inspection, it is established that the tempering strength of the concrete slabs does not meet the requirements specified in clause 1.4.5, delivery of such slabs to the consumer should be made only after the concrete slabs have achieved strength corresponding to the classes of tensile strength in bending and strength for compression (clause 1.4.3).

2.5. Periodic tests on the frost resistance of concrete slabs, as well as on the volume of entrained air in a compacted concrete mixture are carried out at least once every 6 months, as well as when the slab manufacturing technology changes, the source materials and the composition of the concrete mixture used for preparing concrete change.

2.6. The water-cement ratio in the concrete mixture is monitored for each batch of concrete slabs.

2.7. Acceptance of reinforcement and assembly-butt products is carried out before installing them in the mold in accordance with GOST 10922 and GOST 23858.

2.8. Acceptance of slabs in terms of accuracy of geometric parameters, thickness of the protective layer of concrete to reinforcement, surface quality, controlled by measurements, should be carried out based on the results of selective one-stage control.

Acceptance of slabs based on the presence of assembly and joint products, cleaning of their open surfaces and slab edges from concrete deposits, the presence of concrete peeling and grease stains on the working surface of the slab, and the correct application of markings and signs is carried out based on the results of continuous inspection.

2.9. When accepting slabs based on the crack resistance of their lower and upper zones, one slab is selected for testing from each batch of slabs, which satisfies the requirements of this standard in other respects.

It is allowed to use for testing a slab that has cavities, local sagging and chips of concrete, the dimensions of which exceed those allowed by this standard (clause 1.12.3) by no more than twice, and other defects that do not affect the strength of the slabs.

The slab is considered to have passed the test if, under the control load specified in clause 3.8.4, no cracks are detected on the surface of the test zone and side edges upon careful inspection through a magnifying glass with fourfold magnification.

If the results of the crack resistance test are unsatisfactory in at least one zone, additional testing is carried out.

testing two slabs of a given batch. If at least one of two slabs does not pass the test, then all slabs in this batch are tested.

By agreement with the consumer, testing of slabs for crack resistance may be carried out not from each batch, but from a larger number of slabs and at other times depending on the volume of their production, but at least once a month.

2.10. Based on the acceptance results, a document is drawn up on the quality of the supplied slabs in accordance with GOST 13015.3.

Additionally, the quality document must contain:

concrete grade for frost resistance;

class of reinforcing steel used as longitudinal prestressing reinforcement (At-V, A-V, At-IVC, At-IV, A-IV);

grades of reinforcing steel of classes A-I-A-III and grades of carbon steel of ordinary quality, from which assembly and butt plate products are made.

3. METHODS of control

3.1. The strength of concrete, when tested by samples, is determined according to GOST 10180 on a series of samples made from a concrete mixture of the working composition and stored under conditions in accordance with GOST 18105.

Determination of the actual transfer and tempering compressive strength of concrete when testing them using non-destructive methods in slabs (clause 2.4) is carried out using the ultrasonic method in accordance with GOST 17624, mechanical devices or the peeling method in accordance with GOST 22690.

3.2. The frost resistance of concrete slabs should be determined in accordance with GOST 10060 for concrete airfield pavements.

3.3. The standardized quality indicators of the concrete mixture are checked according to GOST 10181.0-GOST 10181.4.

3.4. Methods for monitoring reinforcement and assembly-butt products - according to GOST 10922 and GOST 23858.

3.5. Methods for controlling the raw materials used to manufacture boards must comply with established standards or specifications for these materials.

3.6. Measurement of controlled stress in prestressed longitudinal reinforcement - according to GOST 22362.

3.7. Dimensions, deviations from the straightness of the profile, from the flatness of the slab, from the perpendicularity of adjacent edges, the thickness of the protective layer of concrete to the reinforcement, the position of assembly and joint products, as well as the quality of concrete surfaces and

the appearance of the slabs is checked by the methods established by GOST 26433.0 and GOST 26433.1.

3.8. Control of cracked bone slabs

I - tested slab; 2 - load over the entire width of the slab; 3 - wooden beams with a section of 10X10 cm; 4.- load-bearing baluster

Note. Dimensions in brackets refer to testing schemes for PA G-18 and PAG-20 slabs.

3.8.1. Testing of slabs for crack resistance of the lower zone should be carried out according to scheme A shown in Fig. 6. Testing of slabs for crack resistance of the upper zone is carried out according to scheme A or B, shown in Fig. 6.

3.8.2. Testing of slabs after heat treatment (with the tempering strength of concrete) should be carried out no earlier than 4 hours and no later than 2 days.

3.8.3. First, the slab is tested for the crack resistance of the lower zone, and then the same slab is tested for the crack resistance of the upper zone. When testing the slab for crack resistance of the upper zone according to scheme A shown in Fig. 6, the slab is turned over after testing the lower zone.

The loading of the slab during testing is carried out in stages. The share of the load of each stage should be no more than 10% of the control load, and the share of the last two stages should be no more than 5%.

After applying each stage of the control load, the slab is kept under load for at least 10 minutes, and after applying the full control load - for at least 30 minutes.

3.8.4. The values ​​of the control load for testing the crack resistance of the slab are given in table. 3.

Table 3

Test load. kN (kgf), according to the tested strength of the slabs with the strength of the slab, which complies with it

4. TRANSPORTATION AND STORAGE

4.1. Transportation and storage of slabs should be carried out in accordance with the requirements of GOST 13015.4 and this standard.

4.2. The slabs should be transported and stored in a horizontal position.

4.3. The height of the stack of slabs during their transportation is set depending on the carrying capacity of the vehicles.

and permissible loading dimensions, but not more than the height of the stack of slabs during their storage (clause 4.8).

4.4. Loading of slabs and their fastening during transportation on open railway rolling stock (gondola cars, platforms) should be carried out in accordance with the requirements of the Rules for the carriage of goods and Technical specifications loading and securing of cargo approved by the USSR Ministry of Railways.

The approximate consumption of wire with a diameter of 6 mm for fastening slabs on a train is 1.2 kg per 1 m 3 of transported slabs.

Transport marking - according to GOST 14192.

4.5. Loading, transportation, unloading and storage of slabs should be carried out in compliance with measures to prevent the possibility of damage to the slabs.

The slabs should be transported securely fastened to vehicles, eliminating longitudinal and transverse displacement of the plates, as well as their mutual collision and friction during transportation.

4.6. During transportation and storage, the lower slabs should be supported on wooden supports, and spacers should be placed between the slabs along the height of the stack. Pads and gaskets should be placed at a distance of 1 m from the end of the slab, perpendicular to its long side and vertically one above the other.

The thickness of wooden linings with a rigid base must be at least 50 mm, and with a soil base - at least 100 mm. The thickness of the gaskets is at least 20 mm.

4.7. Loading and unloading operations involving gripping assembly-butt products should be carried out one slab at a time. It is prohibited to lift two or more slabs by grasping the mounting joints of the lower slab.

When using special rigging devices that operate without gripping assembly-butt products, the number of plates in the lifted package should not exceed three,

4.8. The slabs should be stored in warehouses in stacks, sorted by brand and batch.

It is allowed to stack no more than 10 slabs in height.

INFORMATION DATA

1. DEVELOPED by the USSR Ministry of Defense

Research, design and technological institute of concrete and reinforced concrete (NIIZhB) of the USSR State Construction Committee

Ministry of Transport Construction of the USSR DEVELOPERS

B. I. Demin, Ph.D. tech. Sciences (topic leader); K. D. Zhukov; V. A. Dolinchenko, Ph.D. tech. sciences; V. E. Anisimov, Ph.D. tech. sciences; N. B. Vasiliev, Ph.D. tech. sciences; V. A. Kulchitsky, Ph.D. tech. sciences; V. V. Vakhrushev; S. L. Nerubenko, Ph.D. tech. sciences; L. B. Pchelkina; N. I. Shkinin; A. A. Galchenko; I. A. Vavilov; G. I. Berdichevsky, Doctor of Engineering. sciences; N. A. Mar-karov, Doctor of Engineering. sciences; V. Ya. Yakushin, Ph.D. tech. sciences; A. M. Sheinin, Ph.D. tech. sciences; E. R. Pinus, Ph.D. tech. sciences; V. M. Skubko; V. I. Denshchikov INTRODUCED by the USSR Ministry of Defense

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the State Construction Committee of the USSR dated March 12, 1991 No. 8

3. INSTEAD GOST 25912.0-83

4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

GOST 25912.0-91. “Prestressed reinforced concrete slabs PAG for airfield pavements.”

The current standard for the production of highly critical products is road slabs for covering airfields, runways, high-tonnage transport routes, sites of large industrial facilities and logistics centers. PAG slabs are produced in a single size of 6x2 m, differing in thickness of 14.18 and 20 cm. These are prestressed slabs that have a safety margin of up to 75 tons. Rectangular slabs, depending on the type of reinforcement and thickness, are used in various objects. Aviation concrete slabs undergo a number of tests, the methods of which are confirmed GOST25912.0-91. The maximum control load on PAG-20 slabs is 8800 kgf. The cost of a PAG slab directly depends on the reinforcement, mass, thickness and consumption of materials.

GOST 25912.0-91 consists of several subparts that more specifically describe the design, reinforcement and inspection methods of products.

• GOST 25912.0-91 Prestressed reinforced concrete slabs PAG for airfield pavements.

• GOST 25912.1-91
• GOST 25912.2-91 Prestressed reinforced concrete slabs PAG-18 for airfield pavements.
• GOST 25912.3-91 Prestressed reinforced concrete slabs PAG-14 for airfield pavements.
• GOST 25912.4-91 Reinforcement and assembly-butt products reinforced concrete slabs for airfield pavements.

Besides, GOST 25912.0-91 establishes that PAG-18 slabs are suitable for use in various climatic conditions, at design temperatures up to – 60 C. Production airfield slabs PAG-14 is made from the most high-strength concrete grades M300-M400. These are dense concretes of 2200-2500 k/m3, which provide the slab covering with durability and resistance to abrasive wear. The surface of the slab is rough, corrugated, and has a diamond pattern with a depth of at least 1.5 mm. The thickness of the protective layer of concrete up to the reinforcement GOST25912.0-91 not less than 27-32 mm. Finished products are tested for strength, rigidity and crack resistance.

The PAG-14, PAG-18 and PAG-20 slabs are expected to have special endurance and resistance to constant and short-term loads. Such slabs require significant rigidity, which is ensured by placing reinforcing bars and meshes of prestressed reinforcement into the base of the slab. It is these parts that provide the slab coating with resistance to bending, tearing, and cracking. In addition to mechanical strength, airfield slabs must be resistant to systematic temperature changes, freezing, humidity and chemical reagents, for this purpose PAG-14 slabs are produced from resistant concrete with a high level of frost resistance F100-F200 and water resistance W4 or more.

PAG slabs are reinforced with stressed reinforcement from rods with a diameter of up to 12 mm, types steels A-V, A-IV, At-IVC. Meshes made of reinforced non-stressed steel A-III and wire BP-I are also used. Modern manufacturers provide high level quality of airfield slabs, you can buy them using our directory of reinforced concrete products. Slab reinforcement is considered in detail GOST 25912.4-91. You can purchase smooth airfield slabs with delivery throughout Russia. The company "Complex-S" offers minimum prices for residents of the country's regions and an optimal logistics system for the delivery of reinforced concrete products.

The need to construct a highly stable road surface contributes to the popularity and spread of PAG-18 slabs. Today, many builders across the country are trying to buy airfield slabs, perhaps this is due to the poor quality of modern asphalt pavements, or maybe because the service life of PAG-20 slabs is so high that after use they can be safely resold. But only the new PAG-14 slabs can provide maximum reliability and stability; they are produced at a number of flagship reinforced concrete factories, where technologists strictly monitor the production of slabs of a high degree of responsibility.