RU205501U1 - WOVEN POLYPROPYLENE GEOTEXTILE FOR DRAINAGE SYSTEMS - Google Patents

Abstract

The utility model relates to the field of construction and can be used for the construction of drainage systems of various types, the device of protective-filtering and reinforcing layers in embankments on soft soils and in difficult soil-geological conditions and the bases of road pavements, anti-erosion protection and strengthening of slopes, bridge cones and overpasses, dams and banks of water bodies, manufacturing geotubes as containers for dewatering and drying various types of water-insoluble solids and industrial waste, manufacturing geotubes for the construction of breakwaters, dams, breakwaters and artificial islands in hydraulic engineering, as protective shells for ground piles .Geotextile woven filtering, characterized by the fact that it is made in the form of a cloth with a plain and twill weave of polypropylene threads with a melt flow rate of 3-5 g / 10 min with the addition of an antifibrillating additive of calcium carbonate and a UV stabilizer; whether with a linear density of 700-6000 denier and a width of 4-12 mm with a high degree of fibrillation, and flat threads with a linear density of 1000-4000 denier and a width of 1-4 mm are used on the basis, while the filtration coefficient of geotextiles is 40 m / day at a pressure of 100 -200 kPa. The technical result achieved by the declared utility model is to increase the culvert capacity of the drainage system by 1.5-2.5 times, on which it is installed. 3 C.p. f-ly.

Description

Technology area

The utility model relates to the field of construction and can be used for the construction of drainage systems of various types, the device of protective-filtering and reinforcing layers in embankments on soft soils and in difficult soil-geological conditions and the bases of road pavements, anti-erosion protection and strengthening of slopes, bridge cones and overpasses, dams and banks of water bodies, manufacturing geotubes as containers for dewatering and drying various types of water-insoluble solids and industrial waste, manufacturing geotubes for the construction of breakwaters, dams, breakwaters and artificial islands in hydraulic engineering, as protective shells for ground piles ...

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), fastened to 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, 27.04.13).

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 the 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, 010, 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, 04/27/2013, 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 such form has a water-permeable ability. 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 by the 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 degrades 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 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 patent was chosen as the closest analogue.

Known in construction, woven geotextiles and geocomposite materials based on them, when they perform the function of reinforcement, have low filtration and culvert capacity of the woven structure, which limits the scope of their application and reduces the efficiency of geotextiles as part of drainage systems operating under pressure from the weight of road building structures in soil layers and structural layers.

Disclosure of the essence of the utility model

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

The problem is solved due to the fact that the filter woven geotextile, according to the utility model, is made in the form of a fabric with a plain and twill weave of polypropylene threads with a melt flow rate of 3-5 g / 10 min with the addition of an antifibrillation additive of calcium carbonate and a UV stabilizer, at the same time on the weft used threads with a linear density of 700-6000 denier and a width of 4-12 mm with a high degree of fibrillation, and on the basis of used flat threads with a linear density of 1000-4000 denier and a width of 1-4 mm, while the filtration coefficient of the geotextile is 40 m3 / day at a pressure of 100-200 kPa.

The edge of the geotextile is made of embedded, cut and fused with a thermal or ultrasonic method.

The edge of the geotextile is made of the "Leno" type.

The type of thread on the warp is flat double or triple or quadruple.

The technical result achieved by the claimed utility model is to increase the culvert capacity of the drainage system by 1.5-2.5 times, on which it is installed.

This technical result is ensured by:

- improving the filtration of woven geotextiles from the value of the filtration coefficient (water permeability) of 10-20 m / day to the value of 40 m / day due to the type of polypropylene yarns, flat doubled or tripled on the warp and fibrillated in a special way on the weft;

- increasing the service life of geotextiles by increasing resistance to UV radiation, chemical resistance in acidic and alkaline environments, frost resistance (the service life of geotextiles is not less than 50 years, ensuring the required drainage properties in the structures used, taking into account a gradual decrease due to silting of the material with clay particles).

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.

Geotextiles are made of polypropylene yarns on circular and flat-weaving equipment of plain and twill type of weaving with different rapports.

The threads are made of polypropylene with a melt flow rate of 3-5 g / 10 min with the addition of an anti-fibrillating calcium carbonate additive and a UV stabilizer.

The choice of the melt flow rate (MFR) is determined by the required viscosity of the thermoplastic. The higher the MFR of the thermoplastic, the lower its viscosity. Thus, this range was chosen as the optimum between high and low viscosity.

Woven geotextile has the following ratio of components, wt. %:

polypropylene 90-97 special grinding calcium carbonate 2-8 UV stabilizer (Tosaf UV6639PP or Lightform 120601 SB) 1-2

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 influence 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 of the use of UV stabilizers are given without specific disclosure of their compositions, which are not the subject of protection, and with which the in-situ tests of the claimed coating were carried out.

In weft-woven geotextiles, threads with a high degree of fibrillation are used, for which the threads are passed through a rotating fibrillator with the following technological parameters:

fibrillation frequency (number of needles) 7-10 needles / cm fibrillator shaft rotation speed 150-230 m / min force of pressing the thread to the fibrillator shaft 10-15 N

angle of thread pressure to the fibrillator shaft 30-45 °

filament temperature 110-140 ° C

The linear weft yarn density is 700-6000 denier with a width of 4-12 mm with a high degree of fibrillation.

On the basis of used flat threads with a linear density of 1000-4000 denier and a width of 1-4 mm.

The choice of the density and width of the threads is due to the following factors.

Due to the fact that woven geotextiles are used in structural layers of highways of all technical categories, certain strength requirements are imposed to ensure its effective operation under load, which affects the density of threads, namely:

I category of roads - 4000-6000 denier, II category - 3000-4000 denier, III category - 2000-3000 denier, IV-V - category 700-2000 denier.

Depending on a particular density, the width of the thread is selected. Thus, the density of the thread and its width are in direct proportion to each other, in accordance with the specific application of the geotextile.

The choice of the width of the weft thread is based on experiments and is selected empirically, and which directly affects the strength and filtering ability of the geotextile as a whole.

In this case, as is known to the specialist, due to the strength of the warp threads are thinner than the weft threads, which are made thicker (wider). This explains the type of warp yarns, which are preferably triple twisted. However, in other embodiments, it can be a flat type of filaments, as well as with a double or quarter-type twisting of the filaments.

The choice of a filtration coefficient of at least 40 m / day is explained by the practical advantages of geotextiles:

the pace of construction of soil embankments on peat and waterlogged foundations is increasing due to the acceleration of the consolidation and stabilization processes, as well as the reduction in the time required for the dewatering and drying of various types of water-insoluble solids and industrial waste by increasing the filtration capacity of geotextiles made of geotextiles by 30% ...

- reduction of deformation of the pavement bases from frost heaving due to the prevention of excessive moisture;

- increasing the operational reliability of road sections in places where during operation it is possible to increase the moisture content of the subgrade or underlying soil with excess water from the waterlogged subgrade;

However, for lower values of the filtration coefficient, these advantages are not provided.

The pressure of 100-200 kPa is due to the fact that geotextiles can work in structures under high pressure from the weight of road-building structures more than 5 m high.At this pressure, various types of geotextiles are significantly compressed and reduce the cultivation capacity, this explains a wide range of pressures.

To prove the achievement of the claimed technical result, a comparative analysis of the main indicators of geotextiles of the existing state of the art and according to the declared solution was carried out, which is presented in Table 1:

As follows from the table, as well as the tests carried out, the claimed filtering geotextile, with the above characteristics, has, in comparison with the existing state of the art, in addition to high reinforcing strength, the declared increased culverting capacity of the drainage system by 1.5-2.5 times, which confirms the achievement the declared technical result.

Claims (4)

1. Geotextile woven filtering, characterized by the fact that it is made in the form of a cloth with a plain and twill weave of polypropylene threads with a melt flow rate of 3-5 g / 10 min with the addition of an antifibrillating additive of calcium carbonate and a UV stabilizer, while threads are used for weft with a linear density of 700-6000 denier and a width of 4-12 mm with a high degree of fibrillation, and on the basis of flat threads with a linear density of 1000-4000 denier and a width of 1-4 mm, while the filtration coefficient of the geotextile is 40 m / day at pressure 100-200 kPa. 2. Geotextile according to claim 1, characterized in that the edge of the geotextile is made with embedded, cut off and fused with a thermal or ultrasonic method. 3. Geotextile according to claim 1, characterized in that the edge of the geotextile is made of the "Leno" type. 4. Geotextile according to claim. 1, characterized in that the type of thread on the basis of flat double or triple or quadruple.