RU205993U1 - GEOCOMPOSITE GEOTEXTILE FOR REINFORCEMENT OF ROAD STRUCTURES - Google Patents

Abstract

The utility model relates to the field of construction, namely, to the arrangement of the subgrade and the bases of road pavements, and can be used as a reinforcing multifunctional layer. from interlaced tape and multifilament polypropylene threads, and a bottom layer impregnated with a hydrophilic solution based on organosilicone, which is a nonwoven needle-punched fabric with a density of 300-500 g / m2, and a middle layer, which is an adhesive adhesive based on a polymer melt, which is dotted applied to the facing surfaces of the upper and lower layers for the possibility of their bonding with the formation of a geocomposite, while the ratio of the thickness of the upper layer to the lower one lies in the range 1: 2-1: 4. The technical result is the creation of a geotextile geocomposite for embankment reinforcement it, which, due to the woven structure of the geotextile, provides high strength to strengthen road bases and embankments, as well as effective redistribution of the load on a weak base while simultaneously performing drainage, waterproofing and capillary-interrupting functions.

Description

Technology area

The utility model relates to the field of construction, namely, to the arrangement of the subgrade and the bases of road pavements and can be used as a reinforcing multifunctional layer for:

reinforcing the foundations of road pavements and embankments on soft soils in difficult soil-geological conditions, including peat bases, subsiding and plastic clay soils;

flat drainage devices at the base of road cuts and low embankments with unsecured drainage;

devices for waterproofing and capillary interruption of the roadbed in areas with the third type of terrain for moistening and silty, clayey soils of the base without the device of additional drainage layers;

ensuring the stability of slopes of increased steepness or when using local soils with low strength characteristics.

State of the art

Currently, the use of geotextiles in construction is widely known for its use, in particular, as drainage systems, reinforcing layers, geotubes.

Known reinforcing geocomposite material, including a web of needle-punched non-woven material (geotextile), bonded with a polymer material, while the material contains the main layer of geotextile, on which a woven polymer material is applied by a needle-punched method, and in this form has a water-permeable ability (see patent for a useful model RU 127382

A geoplatform for reinforcing a road embankment is known, containing geogrid modules fastened to each other, the cells of which are filled with filler and on top of which an additional filler layer is located, the geogrid modules are placed on woven geotextile webs, while the geotextile webs are located in the transverse direction relative to the axis of the roadway, and the edges of the webs wrapped on each side onto the surface of an additional layer of filler (see utility model patent RU 122100 U1,

Known high-strength composite fabric for excavation, containing the main layer of fabric in the form of a woven geotextile, which is the top layer and non-woven material, which is the bottom layer. The disclosed nonwoven fabric uses a needle punching technique to combine with one another with a woven geotextile, placing a plurality of nonwoven reinforcing materials on the disclosed base fabric layer on the top surface. The lower surface of the fabric is covered with a thin layer of polyethylene film (see utility model patent CN 203331508 U, 11.12.2013).

A similar solution is known from utility model patent CN 203449688 U, 02/26/2014). The solution refers to a kind of composite subgrade, and contains the main layer of fabric in the form of woven geotextile, which is the top layer and non-woven material, which is the bottom layer. The disclosed nonwoven fabric uses a needle punching technique to combine with one another with a woven geotextile, placing a plurality of nonwoven reinforcing materials on the disclosed base fabric layer on the top surface. On the described base fabric layer of the upper surface, spaces are formed to accommodate a plurality of nonwoven reinforcing materials, and the lower surface is provided with a thin layer of plastic foil.

Known drainage geocomposite according to the utility model patent RU 98428 U1, 20.10.2010, containing a geogrid with a two-level structure of placement of its elements, forming cells, and two layers of geotextile, used as an alternative to traditional drainage systems from crushed stone. Due to its low strength, this geocomposite does not provide a reinforcing function in conditions of high traffic loads when erecting embankments on a weak foundation. As a result, construction in conditions of weak and waterlogged soils requires more material-intensive and labor-intensive methods of strengthening the base and ensuring the operational reliability of road structures.

Known reinforcing geotextile material according to patent RU 127382 U1, including a web of needle-punched non-woven material (geotextile), bonded to a polymer material, characterized in that it contains a main layer of geotextile, on which a woven polymer material is applied by a needle-punched method, and in this form has a water permeability ... The disadvantage of this technical solution is that the proposed material does not have reinforcing properties in soil structures under high loads for the following reasons: the connection of the woven polymer material is made using a needle-punched method, in which the needles pierce the threads of the woven structure and its strength indicators are significantly lost by 40-70% ; with insufficient strength of the woven material and low resistance to mechanical damage under a heavy load from the weight of an earth embankment built on a weak foundation, and under the action of heavy road construction equipment, the material will deform with a loss of strength necessary to create a reinforcing effect. In addition, the woven polymeric material made of polyester is short-lived and decomposes under conditions of use in swamps and peat soils, which are characterized by an acidic reaction of the environment (pH 3.0-5.0). To impart waterproofing properties to the reinforcing geocomposite, a polymer waterproof film is added from the side of the woven layer with fixation by the method of thermal bonding. In this case, the composite is heated, which can reduce its strength characteristics. The use of film materials for waterproofing requires the use of special protective technological layers to exclude damage by large-fraction inclusions along the contact boundary. For these reasons, the material cannot be used as a reinforcing layer to strengthen road embankments built on weak unstable bases with an acidic environment, subject to high loads, without a protective layer of fine sand.

This source can be taken as the closest analogue.

Disclosure of the essence of the utility model

The technical problem to be solved by the present solution is an increase in the service life and operational reliability of road structures built on weak waterlogged foundations, as well as a reduction in the time and cost of construction by reducing the consumption of building materials and paving on the roadbed until it is stabilized. ...

The problem posed is solved due to the fact that the multilayer geocomposite, according to the utility model, is made of three interconnected layers: the upper one, which is a woven geotextile with a filtration coefficient of 20 m / day, made of interlaced tape and multifilament polypropylene yarns, and impregnated hydrophilic solution based on organosilicone, the lower layer, which is used as a non-woven needle-punched fabric with a density of 300-500 g / m ² , and the middle layer, which is an adhesive adhesive based on a polymer melt, which is pointwise applied to the facing surfaces of the upper and lower layers for the possibility of their gluing with the formation of a geocomposite, while the ratio of the thickness of the upper layer to the lower lies in the range 1: 2-1: 4.

High-flow polypropylene, polyethylene, calcium carbonate and UV stabilizer are used as polymer melt.

The technical result is the creation of a geotextile geocomposite for reinforcing embankments, which, due to the woven structure of the geotextile, provides high strength to strengthen road bases and embankments, as well as effective redistribution of the load on a weak foundation while simultaneously performing drainage, waterproofing and capillary-interrupting functions.

Implementation of the utility model

Below will be presented a preferred embodiment of the utility model, which, as it is understood by a person skilled in the art, does not limit other possible embodiments arising from the essence of this utility model.

Geotextile geocomposite consists of high-strength woven geotextile, impregnated with a permanent hydrophilic solution based on organosilicone to increase its permeability and filtration, and non-woven geotextiles, interconnected, for example, by lamination or adhesive composition.

Geotextile geocomposite performs a combined function of reinforcement, waterproofing and drainage in a road structure under a traffic load. When reinforced with geocomposite, an increase in the modulus of elasticity of soil layers and a uniform distribution of static and dynamic transport loads on a weak foundation are achieved, which leads to the possibility of reducing the requirements for the calculated degree of its consolidation. The reinforcing effect, depending on soil conditions, can be increased by 15-50% when installing a closed-type reinforced soil cage or geoplatform at the base of the road embankment to limit the lateral movement of the soil. Due to the drainage properties of the geocomposite, the interruption of the movement of moisture from the lower waterlogged horizons to the upper ones is achieved, which improves the moisture regime of the subgrade in the freezing zone and reduces the frost heaving of the structure. The drainage and culvert function of the geocomposite is doubled due to the use of woven geotextile and its impregnation with a hydrophilic solution.

The filtration coefficient must be at least 20 m / day in accordance with the requirements of road standards for geosynthetic materials that perform a drainage (drainage) function. At lower values of the coefficient, the geomaterial cannot be used as a drainage layer. The geocomposite uses high-strength woven geotextile with technical characteristics:

longitudinal and transverse tensile strength, not less than 50 kN / m; relative elongation, no more than 15%;

resistance to aggressive soil media pH = 3-11, not less than 90%.

The geotextile layers are joined by lamination or adhesive bonding, which ensures the preservation of the high strength of the woven structure of the geotextile and provides high resistance to damage by large-fraction inclusions of the structural layers.

Multifilament yarns provide the filtering ability of the geocomposite, ribbon filaments are necessary to ensure the strength of the geocomposite. The organosilicone-based impregnation is designed to increase the permeability of woven geotextiles.

The choice of a needle-punched fabric with a density of 300-500 g / m ² is due to the provision of drainage in thickness - across the material. Tests have been carried out, material with different density options.

In particular, materials with a density of 150 g / m ² , 250 g / m ² , 300 g / m ² , 450 g / m ² , 500 g / m ² were taken. Tests have shown that at a density of less than 300 g / m ² , the required filtration is not provided (the material, in fact, does not fulfill its filtering function). Material in the range of 300-500 g / m ² met the regulatory requirements for filtration, and more than 500 g / m ² gives excess thickness and material consumption.

Thus, the optimal density range was established empirically.

The choice of the ratio of the thickness of the upper layer to the lower one lies in the range 1: 2-1: 4 associated with the use of needle-punched geotextiles with a density of 300-500 g / m ² , the thickness of which exceeds the thickness of the woven material by 2-4 times. The indication of the thickness ratio emphasizes the structure of the material, since at the same density, needle-punched geotextiles can have different thicknesses. A decrease in thickness at an equal density leads to a decrease in the filtration coefficient - the fibers of the material are placed too close to each other; as the thickness increases, the cultivation capacity increases, but at the same time the resistance to cyclic loads decreases - such materials, as a rule, are not used in road construction.

Geotextile geocomposite, when bonded by lamination, has a ratio of polymer melt components: wt. %:

high flow polypropylene 60-70 low-pressure polyethylene 15-20 special grinding calcium carbonate 10-15 UV stabilizer 2-5

The woven geotextile is impregnated with a permanent hydrophilic solution based on organosilicone, for example, Silastol GF16, Finalux 1600.

These are the best known organic lubricants for hydrophilic finishing for temporary hydrophilicity of nonwovens and Silastol PHP 32 and PHP 26 for permanent hydrophilicity. These products can be used to make both spunlaid nonwovens and staple fibers.

As a UV stabilizer, for example, Tosaf UV6639PP or Lightform 120601 SB are used. UV stabilizers for polymers are used to protect the surface from damaging light exposure. Under the sun's rays, polyethylene, polypropylene, PVC fade, turn yellow, paint. Cracks appear on the product, into which moisture and dust penetrate. They are added to the original mixture or applied to the surface of the product. They include: spatially hindered organic compounds, which have a complex branched structure, slow down the movement of radicals, as well as antioxidants, which prevent the destruction of the material under the action of the released oxygen. The use of light stabilizers allows you to absorb light by dissipating heat, slowing down the decomposition processes and reacting with already formed products. The service life of a quality UV stabilizer is up to 10 seasons.

In this application, as examples, only trade names are given for the use of possible hydrophilic solutions based on organosilicone, as well as UV stabilizers without specific disclosure of their compositions, which are not subject to protection, and with which full-scale tests of the claimed coating were carried out.

A comparative analysis of the main indicators of geocomposites is presented in Table 1.

Using a geocomposite according to this solution will allow:

increase the service life of road objects by increasing the strength and performance characteristics and durability of the geocomposite as a result of the use of high-strength woven geotextiles made of polypropylene yarns;

reduce the construction time of embankments on weak unstable foundations by 1.5-3.0 times by reducing the total settlement of the embankment and eliminating uneven deformations associated with heterogeneous soils;

to increase the culvert capacity of drainage systems by 1.5-2.5 times, exposed to loads from the weight of road building structures and transport;

to increase the bearing capacity of the road structure and the modulus of elasticity by 1.3-2.0 times due to the reinforcement of structural layers;

to reduce the cost of construction by reducing the thickness of structural layers of inert materials up to 25% and the total consumption of building materials;

- to ensure the reliability and safety of the operation of the subgrade in areas with a high level of groundwater and seasonal flooding due to waterproofing, capillary interruption and drainage of excess water from the waterlogged subgrade.

The proposed geotextile composite has high-strength reinforcing properties and versatility, since, depending on the conditions of use, it can be produced with drainage and waterproofing properties. The composite material has a high resistance to damage by large-fraction inclusions under the influence of loads of construction equipment and the weight of the subgrade.

As follows from the above Table 1, as well as the tests carried out, the claimed multilayer geocomposite, with the given characteristics, has, in comparison with the existing level of technology, high reinforcing strength when strengthening road bases and embankments, as well as effective redistribution of the load on a weak base while simultaneously performing drainage, waterproofing and capillary interrupting function.

Claims (2)

1. Multilayer geocomposite for reinforcing embankments, characterized by the fact that it is made of three layers: the upper one, which is a woven geotextile with a filtration coefficient of 20 m3 / day, made of interlaced tape and multifilament polypropylene threads, and impregnated with a hydrophilic solution based on organosilicone the lower layer, which is a non-woven needle-punched fabric with a density of 300-500 g / m ² , and the middle layer, which is an adhesive adhesive based on a polymer melt, which is pointwise applied to the facing surfaces of the upper and lower layers for the possibility of gluing them to the formation of a geocomposite, while the ratio of the thickness of the upper layer to the lower lies in the range 1: 2-1: 4. 2. Geocomposite according to claim 1, characterized in that a composition containing high-flow polypropylene, polyethylene, calcium carbonate and a UV stabilizer is used as a polymer melt.