Non-woven material used in road construction. Geosynthetic materials: application in road construction. Transportation and storage of Armicet-SL geogrid

They are made using the following materials:

• Polyester (PET).
• Basalt roving.
• Polypropylene (PP).
• Glass roving.
• Polyvinyl alcohol (PVA) and so on.

Their use makes it possible to significantly increase the strength and service life of various structures.

The modern Russian geosynthetics market, in which PTK United Resources occupies one of the leading positions, is developing more and more actively. More and more construction organizations implement modern technologies, based on the use of the materials in question. And they have already appreciated all the benefits of widespread use geosynthetic materials.

Geosynthetics for road repair and construction

Geosynthetics in construction can not only increase the durability of structures, but also simplify and reduce the cost of the production process itself. Such material will be an excellent basis for any construction project, because it has:

• Excellent resistance to natural conditions.
• Excellent tensile strength.
• Resistant even to aggressive chemical compounds.

Add to this the low weight, which simplifies transportation and the relatively low cost, and the economic benefits become obvious.

Geosynthetics have been used in road construction around the world since the late 1960s. In Russia, such technologies were initially reluctant to take root due to high cost materials that until recently were produced only in Europe. But in last years, thanks to the launch domestic production, they began to be very actively used in our country.

Geosynthetics buy

The geosynthetics we offer (the price on our website is indicated directly from the manufacturer Makhina-TST LLC) complies with all necessary GOST standards and has been certified in Germany. In the catalog you will find:

• ASPHALTEX geogrids and DUALTEX geocomposites, which are used to reinforce asphalt concrete layers ().
• Geogrids GRUNTEX and STRADEX for reinforcing the lower layers of road pavement ().
• DACRON GEO non-woven geofabric used to separate different layers of road pavement ().
• High-strength woven geotextile STABBUDTEX, used for reinforcing fragile bases () and other names.

We guarantee that the cost of geosynthetics from our organization is very affordable!

Geosynthetic materials for road construction are an innovative building material based on polymers (polyethylene, polyamide, polypropylene, etc.), which have been widely used over the last 10 years in Russia. Its use ensures a high level of design solutions and environmental requirements, and also increases the service life of the roadway.

Functions of geosynthetic materials

The main functions performed by geosynthetic materials for road construction:

• Reinforcement (geogrids, geogrids). The material redistributes weight loads, thereby strengthening the road surface.
• Filtration (geocomposites, geotextiles). Composites and textiles allow water to percolate without moving into the base of the roadway.
• Drainage (geocomposites, geogrids). Installed to drain water.
• Strengthening the strength of asphalt concrete layers (geogrid, geogrid). Redistribution of tensile loads and mechanical influences.
• Prevention and control of soil erosion (geomat, geocell). The material slows down erosion, heaving and other soil deformations due to climatic influences.
• Strengthening weak soil (geocomposites, geotextiles). Strengthening the bearing capacity of the soil foundation.
• Separation of fabric layers (geocomposites, geotextiles). Prevent road cake layers from caking.
• Waterproofing (geomembranes, geocompositions). Reduces the flow of liquid media to the subgrade.
• Protection from mechanical damage (geosets, geomats, geotextiles).

Depending on the purpose of the material and the individual characteristics of the soil, geosynthetics can perform one or more functions.

Properties of geosynthetic materials for road construction

Geosynthetics have a number of unique properties:

• Resistant to chemicals and aggressive environments.
• Durability (service life reaches up to 100 years).
• Resistant to high and low temperatures, environmental differences.
• Low material consumption.

Reference. Thanks to the combination of versatility, durability and sustainability, modern projects using geosynthetic materials for road construction can reduce repair time by 2-3 times and reduce consumption building materials. In addition to solving a number of technical problems, geomaterials lead to a tangible economic effect!

Classification and types of geosynthetic materials

When choosing a geomaterial great importance has its type, which is selected based on the assigned construction tasks.

Depending on the function, materials can be of several types of permeability: gas-tight, draining, filtering, insulating.

Based on their structure, geosynthetic materials are divided into the following types:

• geotextiles;
• geogrids;
• geogrids;
• geocomposites;
• geomats;
• geocameras;
• geomembranes.

Geogrids, geogrids

This is a rolled or modular mesh material made from synthetic or polymer threads. It is made on the basis of polyamide, polyethylene, polyester, polypropylene, fiberglass, etc.

Geogrids are larger in thickness and cell size than geogrids. They are actively used to prevent erosion retaining walls, strengthening ravines, road slopes, in the arrangement of automobiles, railways on soft soils. The material also has good reinforcing properties. It is used in road bases, load-bearing platforms, and also to strengthen bridge abutments. Concrete of the minimum grade M200, crushed stone, sand, and soil are used as cell fillers. The maximum effect is achieved due to the adhesion of the cells to the filler. The installation temperature ranges from -40 to +60 degrees. The cell diagonal can be 0.2m, 0.3m, 0.4m. Dimensions range from 2 to 3 m (width), from 5.5 to 12 m (height). Module thickness is from 0.05 to 0.2 m. Tape thickness min 1.5 mm. The tensile load of the weld is from 50% of the strength of the tape.

Geogrid is a durable and at the same time lightweight flexible material. It is available in rolls. The main purpose of the mesh is to avoid interpenetration of layers, reinforcement, alignment and strengthening. Geomaterial is laid in soil or asphalt concrete pavements, including upper asphalt layers. Mesh size from 2.5 to 40 mm. Service life over 50 years.

Based on the method of forming the mesh weave, a distinction is made between double-axle and single-axle mesh. Single-axle geosynthetics involve balancing high long-term loads in one direction. She has flat view with long narrow sections. A biaxial geogrid distributes loads in the transverse and longitudinal directions. Has cells square shape with rigid connections of nodes.

Geotextiles

Geotextiles are roll (sometimes sheet) material made from polypropylene or polyester. High flexibility, strength characteristics, water resistance allow it to be used in many construction work.

In road construction, the material serves to filter moisture, preventing soil from mixing with crushed stone, which prevents the road surface from deforming. Its use reduces the appearance of cracks by 3 times. An important criterion in the choice of geotextiles is density.

In road construction, geotextiles with a density of:

• 200-300 g/m2. Used in the construction of parking lots for passenger vehicles, roads for small vehicles or light traffic.
• 300-400 g/m2. For roads with high loads (freight transport, high traffic intensity).
• 450-500 g/m2. The material is used for temporary roads as a separator between layers of crushed stone.

Based on the texture and method of weaving the threads of the material, they are distinguished:

• Non-woven geotextile. Arrangement of fibers without systemic weave. The fabric is impregnated with special compounds. The material stretches well, but has low strength. Reduces loads on the road base.
• Woven geotextiles. In a woven material, the fibers are interwoven as in a fabric, perpendicular to each other. In this case, two or more strips of threads are used. Woven is more durable and is used in pavement layers. It significantly reduces the load on the roadway.
• Knitted. Consists of connected special scheme fibers Used for media distribution and drainage.

Geocomposites

Geocomposite is a two-, three- and multi-layer structure of geomaterial compositions that combines all the characteristics and properties of the layers used. The main purpose of the material is drainage and filtration. The material is used in the construction of vertical edge drainages of highways and drainages of retaining walls.

On construction market The following combinations occur:

• Geotextile geogrid. For example, a combination of a non-woven filter and a mesh with diamond-shaped cells made from low- and high-density polyethylene compositions;
• Geomembrane-geotextile. In this case, the geotextile acts as a filter, and the geomembrane acts as a waterproofing layer and provides a gap for water to flow out.

The main technical parameters of the material are layer thickness and density.

Geomembranes

Membranes are a continuous moisture-resistant synthetic fabric for insulating layers. Membranes for road construction are characterized by a high-strength polyethylene composition with a layer thickness of 1 to 4 mm. The main difference between membranes and other geosynthetics is their tensile strength, which reaches over 600%. The material is produced in rolls or sheets of many sizes, which allows you to install the flooring with minimal joints.

Advice! A profiled geomembrane is applicable for road construction. If the level of the canvas embankment is high, it is better to lay the membrane at a depth of 0.5 to 1 m from the edge.

Area of ​​application in road construction – silty soils, soils with underground rivers, humid climatic zones. The membrane layer prevents frost heaving and rupture of asphalt layers. Placements for installation can be tunnels, bridges, bridge supports, particularly wet sections of roads.

Reference. For the best effect, manufacturers recommend using geomembranes in combination with geogrid, lattice or geocomposite.

Geomats

Geomat is lightweight material three-dimensional fibrous structure with a cellular structure, providing fixation of the root system of plants and trees. Unlike a grid, its cells are very small and arranged in a chaotic manner. Its shape allows the roots of plants and trees to intertwine with their own fibers. Used to prevent and reduce soil erosion.

The material is produced in mats and overlapped at the bases of retaining walls, slopes and slopes.

Geocameras

Geocameras are applicable in the field of innovative construction, for the construction of hydraulic structures. They are used as a form for filling bulk and medium fraction materials. They differ in height and cell sizes. The material allows moisture and water to pass through well, increases the resistance of the structure to deformation, and is not subject to destruction under the influence of heat, frost, or ultraviolet rays.

The use of geosynthetic materials in road construction in Russia is actively growing. A significant increase in the range and assortment provides a high level of solutions to all kinds of design problems, which gives impetus to improving the quality of the fabric and reducing the use of natural resources.

There is a need to prevent the destructive effect of natural factors on river banks, there is a desire to use wetlands as a support for the foundation, to build several levels of highway interchanges, or you don’t know how to turn the roof of a house into a luxurious garden and solve the issue of purifying groundwater? There is an answer! Geosynthetic materials will help you forget about such problems for a long time.

A huge advantage is the use of high-quality materials, the latest developments this area in the construction of road routes. Achieving any goals you set for yourself becomes possible only with the use of innovative technologies that reduce the cost of financial resources and ensure quality at a high level. The use of geosynthetic materials opens up new horizons in solving the most complex problems of transport construction.

What advantages do geosynthetics have over already known and widely used building materials? How productively and in what area can they be used? These issues are becoming more relevant and acute in the domestic construction industry.

History of creation

More than three thousand years ago, the Sumerians built the Ziggurat Tower. To enhance its strength, reed fibers were added to the brick. Tamarisk branches strengthened the Great Wall of China, made in places of clay and gravel, which was completed in 200 BC. era. The Romans built embankments reinforced with reeds along the bed of the Tiber River.

Natural materials were used to strengthen embankments in Ancient Rus'. Usually these were bushes or trees. They learned to use metal in a later period, but it had short term services.

In the sixties of the twentieth century, old and short-lived materials were replaced by geosynthetics with an ultra-long service life of 120-150 years.

What are geosynthetics?

Modern materials, the creation of which uses natural or artificial polymers, used to increase the reliability of soil or other building structures, are called geosynthetics or geosynthetics.

Polyethylene (PE), polyamide (PA), polypropylene (PP), polyester (PET), polyaramid are organic substances necessary in the production of geosynthetic materials.

Main areas of use:

• protection of overpass cones and slopes from the erosive action of natural factors
• construction of embankments and slopes with great steepness
• strengthening fragile foundations of railways and roads
• creating vertical retaining walls from soil.

There are many options for using geosynthetics in road construction, and each of them involves the use of many different types of geosynthetics. This includes geogrid, geogrid, and geotextiles, which are necessary to increase the strength of foundations. One of the main advantages over commonly used materials is interchangeability and complementarity.

We have managed to accumulate certain experience in the use of each type of geosynthetic materials, depending on the direction of activity and the assigned tasks. A collection of three-dimensional or flat geometric shapes They are geosynthetics and are marketed as geogrids, geotextiles, geogrids, geomembranes, and geomats.

Geotextiles are water-permeable, flat, knitted, non-woven or woven materials made from natural or synthetic polymers that are necessary for use in construction work with soil or other materials and in geotechnical engineering. Knitting is used to connect filaments, threads, fibers and other constituent elements to create knitted geotextiles.

Structure of nonwoven materials

Woven and nonwovens made from polymer bases. By means of thermal bonding of each constituent element, nonwoven materials necessary for separation or filtration are produced as interlayers. In the production technology of non-woven geotextiles - a water-permeable material made from synthetic or natural polymers - a thermal or mechanical adhesive method is used to secure threads, fibers, and filaments.

High elongation and low strength characterize nonwoven materials. To prevent soil mixing, non-woven geotextiles are used as layers for separation or for filtration in drainage systems, since the percentage of elongation at break is seventy. As protection components waterproofing against mechanical damage they are used, for example, in the construction of waste disposal facilities or protecting geomembranes of screens that prevent filtration.

The constituent elements of the structure of woven geotextiles or geofabrics are tapes or threads that are intertwined in mutually perpendicular planes. Geotextiles are used mainly for soil reinforcement.

Geotextiles are permeable to water, practically do not change their shape and volume, and have the highest strength. Hundreds of kilonewtons per meter of width equal the tensile strength of geotextiles, and elongation at break reaches a maximum of 15 percent. That is why, to enhance the load-bearing capacity and increase the strength of soil foundations, geotextiles are used as reinforcing components.

Where are geotextiles not used? These include protective screens that prevent filtration, and landfills for storing and recycling waste, and various designs, serving as the basis for the construction of which soil is used. It is possible to construct volumetric closed devices that are filled with soil, such as geocontainers and geotubes, using woven geotextiles intended for strengthening banks and constructing dams.

Types of geosynthetic products

• Materials that are permeable to water, have a flat or three-dimensional shape, created from polymer bases, but are not related to geotextiles, are called geotextile-like, which include geogrids, geogrids, and geomats.
• Consisting of geotextiles and natural clays, the filtration coefficient of which is very low, as well as materials produced in factories, are called geosynthetic clay mats. You can hear the second name - bentonite mats. They can be used as an alternative to landfills, or screens made from clay, or in the production of anti-filtration curtains or ponds.
• Materials in rolls made from threads or ribbons of polymers and having a cellular structure are called geogrids. They are designed for reinforcing asphalt or soil. Some types have non-woven materials in their structure, these are the so-called composite geogrids.
• Materials, main structural element of which the cell is made of polymer ribbons held together by seams arranged in a checkerboard pattern are called geogrids. They are used both for reinforcing foundations to strengthen them, and for protecting slopes from erosion.
• Volumetric materials, produced in rolls, designed to achieve various purposes and having a different structure from each other, are called geomats. Among the produced geomats there are both for strengthening drainage structures and for protecting against erosion and landscaping slopes and banks.
• Materials used to solve various engineering problems in environmental geotechnics as insulating agents consisting of sheet-shaped polymers are called geomembranes. These are polymer materials in rolls, produced for the purpose of insulating underground structures from steam, gas and water, as well as in the construction of various protective screens, artificial ponds, evaporators, settling tanks, and so on.

Application area

The use of geosynthetic materials has been known in international construction for over thirty years. High rates of development characterize the production of geosynthetics. Today, more than 380 types of them are supplied to the international market. For temperature insulation, an incredible variety of various types of geofibers, geogrids, geotextiles, geoplates, geocells, and geogrids are presented to the attention of everyone who is interested. And each of the materials presented above differs from each other in the production mechanism, components, purpose and scope of application, volume, length, characteristics, properties, and so on.

Every year, geosynthetics are proposed to be used in more than one hundred thousand different construction projects around the world.

There are two main reasons for its widespread use.

1. The economic side is associated with cheaper, less costly and, as a result, more profitable construction, repair and maintenance of various highways, roads, and railways. In light of the environmental aspect, geosynthetic materials are considered as an opportunity to reduce the amount of natural resources used and thereby have a beneficial effect on the environment.
2. Also, when using geosynthetics as complementary materials in construction, it is possible to increase the service life of constructed structures and achieve the highest level of work performed, thereby reducing the percentage of defects and defects, increasing the cultural side of production.

In the CIS countries, there is an acute question about the possibility of using the latest scientific achievements in the field of road construction and nature conservation. Today this is one of the most pressing and pressing problems. Among which are unfavorable climatic conditions with a large interval in temperature values, the difficult geological conditions of these places, roads created more than four decades ago, many of which have long been in unusable condition, are the main ones. With today's increase in the number road transport, and the ever-increasing load on roadways, the problem of increasing the reliability and durability of the roadway, its resistance to cracks and resistance to shear, is becoming increasingly urgent. The bulk of roads are designed only for small loads, no more than six vehicles per axle. However, modern conditions dictate the need to produce cars that exert up to 10 tons of load on the road axle.

Often, heavier vehicles can be found in traffic. The level of traffic flow is also increasing every day and already now amounts to 45-50 thousand vehicles in certain areas, which in turn are designed for a load of no more than 6 thousand units. Therefore, many road surfaces are very worn out, are not suitable for performing their functions and require frequent repair work.

Modern market relations involve the use of construction means and forces to greater advantage. If, for example, asphalt is reinforced using geogrids made from glass roving, this will reduce the thickness of the latter by 20 percent.

Construction of roads with geotextiles

Geosynthetics are used in many areas of road construction: the construction of drainage structures, the breakdown of the road surface into separate layers, the strengthening of embankments, the reinforcement of asphalt pavement, the construction of walls that serve as support, and the creation of slopes with high steepness. Volumetric geogrids, geogrids, geotextiles are used, if reinforcement is necessary, for the purpose of constructing structures from soil or creating slopes with increased steepness. An undoubted proof of the preferable choice of geosynthetic materials over the traditional construction of concrete retaining walls, sheet pile fencing structures, or simple soil replacement is the economic side of the issue. You can use dispersed reinforcement of asphalt, which includes the use of fibers from polymers, geogrids and composite materials made on their basis.

Construction of underground structures

For reservoir and wall-type drainage structures, geomats are used, which help solve problems such as hydro- and vapor barrier of the part of the building located underground, elimination of hydrostatic pressure exerted groundwater, and when concreting walls, it also serves as formwork. For the purpose of hydrological insulation of underground structures, geomembranes are used, which have increased resistance to various physical and chemical influences and better elasticity in comparison with commonly used materials.

Construction in the field of nature conservation

Geosynthetic materials can be used as soil erosion control agents, or for landscaping and protective function shores. To do this, you can use anti-erosion mats, the use of which is more profitable than traditional stones, concrete and wood. Geomats promote the rapid development of the root system and protect the soil from erosion even before the vegetation cover appears. When constructing structures for waste disposal and storage, it is necessary to provide insulation from gases and water, build drainage systems, ensure sustainability - geosynthetic materials, which are widely used in this area, will help with all this.

Hydraulic engineering

For the construction of screens providing waterproofing protection

• reservoirs,
• ponds,
• reservoirs,
• curtains,

In order to prevent seepage, dams and dams have successfully used geosynthetic materials such as bentonite clay geomats and geomembranes. Guaranteed protection for long years Geomembranes will protect against the destructive effects of water factors, even in extreme conditions.

But these are not all areas of application of geosynthetic materials; with their help, you can plant trees on any plot of land, build a garden on the roof of your house, or make a sports ground.

Before giving preference to any type of geosynthetic material, it is important to understand that the properties of each of them depend on the structure of the polymers used for their production. And this, in turn, determines such characteristics as

• resistance to temperature changes,
• strength,
• reliability,
• durability,
• ability to withstand any aggressive environmental factors.

It is impossible to achieve success in the use of geosynthetic materials if you do not strictly follow all the instructions and rules for their use.

• Geosynthetics must be laid on a strictly flat surface.
• Subsidence is directly related to providing the required tension.
• Also very important point is to comply with all the rules and regulations for the connection of geosynthetic materials and the formation of an overlap between them, as a result of which a single fabric should be obtained.
• In order not to deteriorate the quality and get satisfaction from the expected, it is necessary to follow all the recommendations.

Market situation

With greater confidence, geosynthetic materials are conquering modern market. The high pace of development of the construction industry predetermines the use of scientific and technological progress and innovative technologies, which are what geosynthetics are. More details about the current situation at Russian market sales read our publication

The use of geosynthetics in construction already has its own history, albeit a short one. Geosynthetics in the form of geotextiles have been used abroad since the late 1960s. The production of these materials in the world has developed rapidly, and currently the world market offers a large number of different types of geotextiles, geogrids, geogrids and geocells, geothreads, as well as geoplates used as thermal insulators.

They all differ in their purpose, the composition of the feedstock, production technology, polymer consumption, physical and mechanical characteristics, width of the webs, etc.

In particular, geotextiles (non-woven fabrics of needle-punched or glue method production) are made from synthetic fibers: polyester (lavsan), polypropylene, polyamide (nylon); geogrids - made of polyester or polypropylene threads increased strength, glass rovings; geoplates - based on polystyrene.

The Russian experience in using geosynthetics began in the mid-70s, first with the purchase of these materials abroad, in particular in Hungary and Czechoslovakia, then with intensive scientific research in industry research institutes and own developments of manufacturing enterprises.

Currently, approximately 380 different types of geosynthetic materials are produced in the world. Geosynthetics are used in transport, hydraulic engineering and civil construction.

They are designed to create additional layers:
- reinforcing layer - strengthens road structures for transport purposes (slopes, embankments, parking lots, foundations, etc.), at the base of which layers of bulk materials;
— protective layer- slows down erosion, prevents interpenetration of contacting layers, thereby solving the problem of mirror cracks, which is characteristic of old roads;
— filter layer - slows down the penetration of soil particles into drainages;
— drainage layer - accelerates water removal;
— waterproofing layer- reduces, and in some cases eliminates, the flow of water into the working layers.

Often, to counteract erosion phenomena on roads that run along the banks of rivers, canals, and seas, slopes are strengthened with concrete, asphalt, stone filling is made, and expensive biological engineering work is also carried out. Over the past 30 years, geosynthetics have been used for these purposes.

The advantages of geosynthetic mats include their durability (service life up to 100 years), tensile strength and elongation, flexibility, low weight and low construction costs. In general, the technological and operational advantages of geosynthetic reinforcing elements compared to traditional methods of constructing roads, slopes, and foundations are as follows:

— immediately after excavating the natural soil, it is possible to build a foundation on a protective layer;
— a non-freezing base under the structure is not required, since the reinforced soil structure does not feel deformation;
— by increasing the load-bearing capacity of the subgrade under the connection paths, soil or crushed stone can be saved;
— the costs of transporting geosynthetic reinforcing elements are significantly lower than the costs of delivering concrete or additional soil, crushed stone, sand.

The use of geosynthetics is envisaged in projects of more than 100 thousand different structures annually all over the world. The reasons for this are based on two main factors:
- economic - the use of geosynthetic materials can significantly reduce capital investments in the construction, repair and maintenance of highways;
- environmental - the use of geosynthetic materials is beneficial to the environment (consumption is reduced natural materials, the volume of preparatory geotechnical work is reduced).

Additionally, the use of geosynthetics allows:
— increase the durability of subgrade structures and road pavements;
— improve the quality of work;
- reduce the amount of rework ( additional work);
— improve production standards.

The relevance of introducing innovative technologies in road construction and environmental protection measures today is obvious and indisputable. This is the continental nature of the climate of individual regions with a large temperature difference, and the presence of territories with complex geological conditions, and the very condition of the roads, most of which were built 40-60 years ago and are designed for lower loads and traffic intensity.

The conditions of a market economy and economic independence force builders to count money. For example, the use of geogrids made from glass roving to reinforce asphalt concrete makes it possible to reduce the thickness of the latter by up to 20%.

Road construction is one of the earliest applications of geosynthetic materials. Geotextiles, geogrids and meshes have been successfully used for their ability to separate, filter, drain and reinforce soils in the construction and reconstruction of both paved and non-paved roads.

The use of geosynthetic materials in road construction provides engineers with a variety of design solutions that can improve road performance from an economical perspective. Geosynthetics can be used in the construction and reconstruction of paved roads for reinforcement, separation, filtration and drainage. They are also used as structural component, providing control over damage caused by construction equipment.

The effectiveness of using geotextiles as a separating layer in the construction of buildings and structures in the foundations of structures and on temporary roads has been proven. The reduction in construction costs according to the estimate is 20% due to a reduction in construction time and transport and operating costs. Today, the geomaterials market in our country is considered the most promising and dynamically developing of all construction materials markets.

n1.docx

FEDERAL EDUCATION AGENCY

Federal state budget educational institution

higher professional education

"TYUMEN STATE OIL AND GAS UNIVERSITY"

INSTITUTE OF TRANSPORT

Department: "TTS"

on the topic: “The use of geosynthetic materials in road construction”

Completed: art. gr. MSO-07-1

Mikurov I.S.

Checked by: Yarkin A.V.

Tyumen 2011

Introduction

Geosynthetic materials have become quite widespread in the strengthening of highways; otherwise it is called: “Reinforcement of highways.”

The scope of geosynthetics is very wide, and their use is effective. Geosynthetic materials have been used in Europe for several decades, having practically revolutionized road, civil and special construction. Economic efficiency and wide range of application of geosynthetics, incl. in areas where they are practically irreplaceable, we can talk about them as very promising materials.

The use of geosynthetics in road construction already has its own history, although not a very long one. Geosynthetics in the form of geotextiles have been used abroad since the late 60s.

The production of these materials in the world has developed rapidly, and currently the world market offers a large number of different types of geotextiles, geogrids, geogrids and geocells, geothreads, as well as geoplates used as thermal insulators. They all differ in their purpose, the composition of the feedstock, production technology, polymer consumption, physical and mechanical characteristics, width of the webs, etc. In particular, geotextiles (non-woven fabrics using a needle-punched or adhesive production method) are made from synthetic fibers: polyester (lavsan), polypropylene, polyamide (nylon); geogrids - made of polyester or polypropylene threads of increased strength, glass rovings; geoplates - based on polystyrene.

1. History of the development of the use of geosynthetic materials in the Russian Federation

The Russian experience in using geosynthetics began in the mid-70s, first with the purchase of these materials abroad, in particular in Hungary and Czechoslovakia, then with intensive scientific research in industry research institutes and the own developments of manufacturing enterprises. Currently, approximately 380 different types of geosynthetic materials are produced in the world. The use of geosynthetics is envisaged in projects of more than 100 thousand different structures annually all over the world.

The reasons for this are based on two main factors: economic - the use of geosynthetic materials can significantly reduce capital investments in the construction, repair and maintenance of highways; environmental - the use of geosynthetic materials is beneficial for the environment (the consumption of natural materials is reduced, the volume of preparatory geotechnical work is reduced, etc.).

Additionally, the use of geosynthetics allows:

• 
  increase the durability of subgrade structures and road pavements;
• 
  improve the quality of work;
• 
  reduce the amount of rework (additional work);
• 
  improve production standards.

And finally, the conditions of a market economy and economic independence force builders to count money. For example, the use of geogrids made from glass roving to reinforce asphalt concrete makes it possible to reduce the thickness of the latter by up to 20%.

2. Geosynthetics

Geosynthetics (geosynthetics) are a group of synthetic materials that are widely used in road and civil construction; the use of geosynthetics opens up new opportunities for solving a variety of problems in the design and construction of roads, as well as complex engineering structures.

Geosynthetics are polymer materials designed to change the natural properties of soils. The change, as a rule, concerns the filtration properties of the soil (usually the filtration coefficient of too loose soil is reduced), or its strength characteristics (for example, the strength of weak soils is increased using geogrid reinforcement).

Specialists from the geosynthetics department of the Euroizol company offer the following definition of these materials: “Geosynthetics is a material in which at least one of the components is made of a synthetic or natural polymer in the form of a canvas, tape or three-dimensional structure, which is used in contact with the soil and other construction materials. materials. The combination of soil with GS should be considered as the formation of a new composite material, which combines the functions of both soil and synthetic material."

The qualitative and chemical-physical characteristics of geosynthetics are determined by the properties of the polymers used for their production. Thus, qualities such as water and frost resistance, corrosion resistance, low weight, high tensile strength are the “merit” of polymers. At the same time, disadvantages polymers (rapid aging under the influence of UV radiation, loss of strength at a temperature of + 80 -120°C, flammability) are leveled out by the specific application of GS. Materials are used in structures, the vast majority of the volume of which is soil or bulk rocks, protecting polymers from light and temperature influences.

Geotextiles are considered the progenitor of geosynthetic materials. The same foreign standards were originally created for these materials.

Depending on the area of ​​application in soil structures, geosynthetics in general can perform the following functions:

• 
  reinforcement to improve the shear resistance of granular materials;
• 
  separation, to maintain the structural integrity of the granular layers;
• 
  filtration, for the passage of liquid and retention of soil particles;
• 
  drainage for collecting and draining liquid outside the structure;
• 
  Erosion control, when preventing soil erosion due to water or wind;
• 
  protection, to prevent damage to the structural layer, such as insulation around artificial structures in subgrade when filling them;
• 
  insulation to prevent migration of liquids and gases.

The first biaxial geogrid was produced in the 1980s by extruding a polyethylene or polypropylene web, perforated after stretching. regular network template holes. Such extruded and oriented geogrids are called inelastic (rigid) geogrids. Biaxial geogrids are widely used in the construction of roads, airfields, container sites, parking lots, etc. on weak and heterogeneous soils.

The basic principle of operation of biaxial geogrids is to eliminate the interpenetration of structural layers and fix the filler due to the wedging of its particles in the geogrid cells. When filling and compacting geogrid cells with inert material, particles of the material are fixed in the cells, and a “mechanical stabilization” effect is created. Biaxial geogrid has high rigidity, which allows it to withstand high loads at low deformations.

Rice. 2.1. Biaxial geogrid

Advantages of use:

• 
  increasing the bearing capacity of the base of the fortified area;
• 
  separation of non-cohesive layers, protection against penetration of coarse-grained material into the lower layers;
• 
  reduction of deformations due to frost heaving;
• 
  allows you to avoid increasing the thickness ballast prism on soft soils;
• 
  reduction in the rate of foundation settlement;
• 
  increasing the speed limit (railway base).

SSNP geogrids are geosynthetics made from impregnated thread-stitched glass meshes. They are used in the construction or repair of hard road pavements with asphalt concrete pavement. The use of geogrids in road construction allows us to solve a number of existing problems.

Geogrids SSP - Neftegaz geosynthetics designed for reinforcement, stabilization of soft soils, construction of temporary roads, ensuring local stability of slopes and slopes.

Rice. 2.2. Geogrid

Glass geogrid brand SSNP-34BT produced by JSC STEKLONiT (Ufa) is a mesh of two layers of roving, fastened together with a stitching thread and impregnated with a binder to increase strength and adhesion to asphalt concrete. Let us consider the mechanism of interaction between the SSNP grade geogrid and the asphalt concrete layer. Asphalt concrete is an ideal material for constructing non-rigid pavements, since, due to the high viscosity of the asphalt binder and the roughness of the aggregate grains, it has high resistance to short-term loads.

Tests of samples - beams made of two-layer asphalt concrete (top layer 3 cm thick, bottom layer - 4.5 cm), reinforced with a road mesh located between the layers of asphalt concrete, and control - unreinforced ones - showed that reinforcing asphalt concrete with SSNP brand mesh slightly increases ultimate force and relative bending deformation. However, it was also revealed that to destroy asphalt concrete samples with a road grid, 2.85 times more is required energy costs, and, consequently, the rate of crack formation in asphalt concrete slows down by the same amount. Thus, the SSNP mesh increases the elastic properties of asphalt concrete, increases its distributing capacity, as a result of which the stresses from the car wheels are distributed over a larger area, which helps reduce stress concentration and, therefore, slows down the process of crack formation. In addition, the mesh increases the resistance to tearing of the road surface by ice, which is important for regions with harsh climatic conditions.

In terms of their operational characteristics, the road nets of JSC STEKLONiT are not inferior to the corresponding foreign materials and can significantly increase the transport and operational performance of coatings, increase the time between repairs, and in general free up material resources for other types of work and objects. SSNP grids have proven their exceptional qualities in a number of projects. Fiberglass meshes of JSC STEKLONiT were used when laying roads in St. Petersburg, Moscow, Astana, and during the reconstruction of airports in Nizhnevartovsk and Khanty-Mansiysk.

Geotextile high-strength stabilex

Geotextile Stabitex (geofabric) - belongs to the section of geosynthetics and is a woven fabric made of high-strength polyamide threads. Used for the construction of embankments of increased steepness from bulk materials construction of retaining walls; protection of territories from landslide phenomena; separation of soil layers; strengthening the foundations of railways and highways, stabilizing soft soils. High-strength geotextile Stabitek is an analogue of the following materials: geolon, polyfelt, typar, kortex.

Rice. 2.3. Geotextile (geotextile)

Geotextiles (dornit)

Geotextile (dornit) – geosynthetic material is a needle-punched or spunbond non-woven fabric made from polyester fibers. Excellent physical and mechanical characteristics of Dornit geotextiles, as well as the widespread use of it in the most different areas, allow us to assert that Dornit geotextiles are the leader among geosynthetics in terms of the range of applications both in construction and in everyday life.

Rice. 2.4. Geotextiles (dornit)

Application of geotextile dornite:

• 
  geotextiles are used as a separating layer (filter) between the soil and aggregate (sand, crushed stone, etc.);
• 
  prevents the penetration of soil particles into drainage systems (drainage of basements, flat roofs);
• 
  During the construction of tunnels, geotextiles protect the insulating coating from damage and form drainage layer, removes soil and storm water to drainage;
• 
  dornite geotextile acts as a filter under the coastal fortification;
• 
  High-density geotextiles can be used as a reinforcing layer on weak-bearing soils;
• 
  used to strengthen the bottom of settling tanks treatment facilities, simultaneously acting as a filter, replacing the layer of sand;
• 
  used as heat and sound insulation;
• 
  when laying pipelines as ballast.

One of the promising structures for volumetric soil reinforcement is the geotechnical grid (geogrid). Geogrid is a geosynthetic material that is a flexible compact module consisting of interconnected plastic tapes, forming in an extended position a spatial cellular structure with given geometric combinations and dimensions. Geogrids are resistant to ultraviolet radiation, fresh and salt water, chemical exposure to soil and aggressive environments. And most importantly, the material is durable, non-toxic and environmentally friendly. The combination of these factors determines the technological effect of using geogrids.

Wide application is due to high physical and mechanical properties: strength, low material consumption to the effects of weather, climatic and hydrogeological factors, durability and environmental safety.

Depending on the construction conditions, reinforcement using geogrids can be either single-layer with a horizontal layer of geotextile, or multi-layer, ensuring uniform reinforcement of the entire massif of the earthen embankment.

Rice. 2.5. Geogrid volumetric

Application of geogrids:

• 
  strengthening slopes and slopes, increasing the overall stability of slopes;
• 
  railway construction. Strengthening the ballast prism;
• 
  development of construction sites with minimal costs;
• 
  strengthening pipeline protective structures;
• 
  the use of geogrid makes it possible to use local materials during construction;
• 
  reduction of direct costs by replacing traditional load-bearing, protective and insulating types of reinforcement by up to 20% of their cost;
• 
  during the construction of airfields.

Rice. 2.6. Geogrid volumetric

Geomembrane

HDPE geomembrane is a rolled waterproofing geosynthetic material made from polyethylene. high density. Reliably protecting, ensuring waterproofing and absence of dampness in buildings is one of the main tasks of modern construction design. Those who understand how important it is to ensure the reliability and safety of buildings and structures are no longer satisfied with the currently existing waterproofing systems; That's why the HDPE geomembrane was developed.

The geomembrane is characterized by high strength and resistance to various substances; This is a product that, thanks to its numerous protrusions, allows the surfaces to be protected to be ventilated and moisture to be removed from them.

Applications of HDPE geomembranes:

• 
  waterproofing and strengthening of slopes;
• 
  during the construction of reservoirs and irrigation canals;
• 
  protection of the outside of the walls;
• 
  protection of retaining walls;
• 
  replacement of lean concrete (pillars under the foundation);
• 
  ventilation and drainage of internal walls;
• 
  ventilation and restoration of old premises (protection inside walls);
• 
  protection and double waterproofing;
• 
  drainage, waterproofing and root protection;
• 
  strengthening, thinning and insulation;
• 
  waterproofing and erosion protection;
• 
  waterproofing and load distribution (during tunnel construction).

Rice. 2.7. Geomembrane

3. Geosynthetic materials in road construction

The intensification of road construction, as operators of the geosynthetics market hope, will have a positive effect on sales volumes of these materials. Firstly, this segment is one of the main consumers of geosynthetics. Secondly, domestic road construction enterprises are increasingly turning to the use of more modern materials and technologies, which, of course, include geosynthetics.

In this segment, geosynthetic materials are used to construct slopes of increased steepness, retaining walls, and strengthen the bases of road embankments. In addition, geosynthetics are used to protect overpass cones, reinforcement asphalt pavements, separating the structural layers of the road “pie” as elements of drainage systems.

In road construction, various types of geotextiles, both woven and non-woven, are mainly used. In this case, their more or less pronounced characteristics are taken into account - mechanical, filtering.

In addition to geotextiles, geogrids are widely used to strengthen (reinforce) slopes or road surfaces. The use of geogrids makes it possible to achieve significant savings in building materials: for example, reinforcing a layer of crushed stone in a road construction system “gives” 60-70% savings in the same crushed stone.

The use of geosynthetics is economically more effective than traditional technologies such as the construction of concrete retaining walls and soil replacement during construction on weak foundations. In railway construction, geosynthetics are mainly used for reinforcing railway tracks and embankments (geotextiles, geogrids).

Moreover, it is almost impossible today to carry out high-quality construction of runways and bridges without geosynthetics that meets all requirements, as experts note. Often these objects are built on weak soils, and therefore require reliable and durable reinforcement.

4. Application of geosynthetic materials

When constructing roads (from pedestrian to railway) and parking lots, crushed stone is usually used. But over time, ruts form on the road on a weak foundation (clay, peat or waterlogged soils), or the crushed stone generally “sinks.” Geotextiles help solve these problems by preventing the crushed stone backfill from mixing with the base and maintaining the original thickness of the backfill, which, in combination with the significant elastic modulus of the geotextile itself, allows:

• 
  significantly increase bearing capacity such a design;
• 
  ensure an increased degree of compaction during the construction phase, preventing crushed stone from being pressed into the soft substructure;
• 
  reduce road damage caused by frost. Trapped tiny particles (fine inclusions) act like a sponge, absorbing water and expanding when frozen;
• 
  prevent rutting.

• 
  reduction in installation costs (reducing the use of crushed stone to achieve the same load-bearing capacity);
• 
  reduction of construction time due to faster and better compaction;
• 
  cost reduction Maintenance and increasing the service life of the structure.

Geotextiles are also widely used in the construction of paths and platforms from paving slabs. Soft (without concrete screed) laying paving slabs is much lower in price (the difference in the cost of concrete and reinforcement and work reaches 70%), it prevents sand from being washed out, mixing it with crushed stone or soil base, increases the rigidity of the structure and significantly reduces the likelihood of subsidence. You get an excellent result, the possibility of easy repairs and redevelopment with significantly lower material, labor and time costs.

Embankment reinforcement

Rice. 4.1. Reinforcement scheme

Used to reinforce fine-grained, cohesive soil.

• 
  Prevents slope collapse.
• 
  Reduces increased pore pressure of the soil.

Firstly, their use makes it possible to optimize economic costs and ensure high quality construction work on reinforcement and waterproofing of structures and structures, the basis of which is loose rocks - soil, sand, gravel mixtures, etc.

In global construction practice, geosynthetic materials have made significant changes in many aspects of transportation and civil engineering practice in less than 30 years. If in the 70s of the 20th century there were only 5-6 hydrocarbons on the world market, then in 2000 their number was about 600. The volume of use is 1 trillion square meters. m per year for a total amount of about 1.5 billion USD. Such growth rates and volumes indicate the extremely wide application and effectiveness of HS in construction due to their properties and functions in structures. In many cases, the use of GS can significantly increase safety margins, durability and reliability, improve performance and reduce cost compared to traditional design solutions.

Thus, according to experts in the field of geosynthetics, the use of geosynthetics in road construction, for example, geotextiles to combat “reflected cracks” Polyfelt PGM 14 and PGM G (repair of asphalt concrete pavements of highways) reduces stresses in areas of old cracks by up to 40% due to the absorption of deformations between the old and new coating. And the overall effect of the use of these materials is a significant slowdown in crack formation, a threefold increase in the time between repairs, savings on road operation, regular routine and extensive repairs and reinforcement of the pavement. Secondly, the area of ​​effective use of geosynthetics is not just wide. The materials work great where the use of other solutions does not provide such a reliable and durable result. Domestic construction production, in contrast to the West, geosynthetic materials began to be “considered” directly from the perspective of widespread use relatively recently, and the list of problems associated with the use of this material is quite standard. There is no official Ukrainian classification of these materials, which stems from a completely traditional situation - the lack of standards. And awareness of the properties and advantages of GS customers still leaves much to be desired.

Conclusion

The use of geosynthetic materials in road construction makes it cheaper and makes it much stronger. The use of geosynthetics is economically more effective than traditional technologies such as the construction of concrete retaining walls and soil replacement during construction on weak foundations. The use of geotextiles significantly increases the bearing capacity of the road; provides an increased degree of compaction during the construction phase; reduces road destruction caused by frost; prevents rutting.

With the use of geosynthetic materials, the cost of maintenance is reduced and the service life of the structure is increased.

Geosynthetic materials are used in all branches of construction. These are the materials of the future. Their development must increase.

Their use improves both the construction itself and its operation. The service life of structures using geosynthetic materials increases. We need to use more geosynthetics.

Bibliography

1. SNiP 2.05.02-85. Highways/Gosstroy USSR.-M.: CITP Gosstroy USSR, 1986.

2. Educational and methodological manual to the implementation of abstracts on the disciplines "Engineering Geology" and "Engineering and Construction Karstology" / ed. Mulyukova E.I. USNTU, 2009. 29 p.