When building a foundation, builders are faced with a situation where it is necessary to strengthen the ground. These works can be done in several ways, but the simplest is the use of geotextiles. It is a special material used in the construction of buildings and structures, as well as strengthening road surfaces.
With the help of geotextiles it is possible to strengthen slopes and slopes. It is made on the basis of polyester and polypropylene fibers, and the production methods are based on needle punching and hydrobonding. The technology includes heat-setting and calendering, which provides water resistance and increased durability.
Basic Features
Geotextile for the foundation has certain properties, among them should be highlighted:
- moisture resistance;
- mold immobility;
- high strength;
- ability to maintain original weight.
In progressoperation, the material is resistant to aggressive chemicals, it is not exposed to fungus, it is not afraid of insects and rodents, which simply do not show interest in the lining canvases. Geotextiles are resistant to punctures, tearing and stretching, which is very convenient when it is necessary to protect the building from plant roots, which can seriously damage the base without proper protection. The material does not absorb moisture, therefore, even under appropriate conditions, the rolls retain their original weight, as well as all the specified properties.
Main Specifications
Geotextiles for the foundation are selected according to several parameters, for example, the thickness and width of the web, the filtration coefficient, the tensile load, and also the surface density. The geotextile can be non-woven and woven, the former is quite widely used in construction. Thickness is not such an important characteristic, because it depends on density. This parameter can be changed from 0.8 to 1.8 and from 2.4 to 3.8 mm.
If you want to choose a geotextile for the foundation, then you should pay attention to one of its main characteristics - surface density. It is measured in g/m2 and can be equal to the limit from 80 to 1000, as for the needle-punched geotextile. If you have a thermally bonded material in front of you, then its maximum surface density can reach a value of 600 g/m2, while the minimum value is 100. A larger numerical value indicates a more impressivestrength.
Need to use geotextile
Quite often, novice home craftsmen wonder if geotextiles are needed for the foundation. The answer to this question will be an unequivocal “yes”. The soil under the foundation must be strengthened. There are many ways to do this today, but the most effective and simplest is the use of geotextiles. The materials at the base of the foundation require protection from negative factors in the form of moisture and exposure to chemicals.
Cloths are able to reinforce weak soils when there is a need to redistribute the load at the base of the embankment. If you carry out the correct laying of the material under the sand cushion, this will eliminate the mixing of sand with the ground. Once you have decided which geotextile to use for the foundation, it is important to consider another of its functions - drainage.
Even a foundation that does not go too far into the ground is constantly exposed to groundwater, which negatively affects the strength of the structure. The use of geotextiles allows you to install a drainage system that prevents the formation of perched water and diverts water away from the building.
How to choose geotextile depending on density
When choosing a geotextile, you need to decide on the type of material in the base. If it is a needle-punched lining, then its density should vary from 350 to 600 g/m2, which will depend on the parameterssoil and building mass.
Thermobonded geotextile is produced by heat treatment and fiber soldering, resulting in improved elongation at break and modulus of deformation. Such a fabric is stronger than needle-punched and has a longer service life. In order to protect the base, it is necessary to purchase a heat-set geotextile, the density of which is 200 g/m2. This is true for a residential building.
Choice of geotextiles according to other parameters
When choosing a geotextile for the foundation, you can pay attention to the hydro-punching material made of polypropylene monofilament. It is great for building technology. Rarely used today are polyester needle-punched endless filament geotextiles. Woven staple modifications do not have sufficient strength, so it is better not to use them in construction.
If there is soil prone to swelling on the territory, it is better to choose geotextiles designed for non-metallic soil. In this case, the density should not be higher than 300 g/m2, so it is recommended to use polypropylene monofilament fabrics in this case.
When it is planned to lay geotextile under the foundation cushion, which must be protected from freezing and getting wet, you should purchase a material of medium density, which varies from 100 to 150 g/m2. This option is budgetary and helps to increase the resource of the structure.
Laying technique: ground preparation
In order to achieve maximum efficiency in the operation of the geoweb, you should adhere to the technology of its installation. It includes surface preparation. Soil irregularities must be eliminated, cracks repaired and soil layers well leveled, forming drainage. If this is difficult to achieve, it is necessary to add sand and compact it well.
Laying the web and connecting the layers
Laying geotextiles under the foundation involves rolling out rolls and spreading them on the surface of the material so that the canvases overlap each other with an overlap of 30 cm. Each new layer is placed on the aligned previous one. Otherwise, you will run into a material shifting problem, which will make it difficult to bond the segments together.
Geotextiles, the properties and characteristics of which were presented above, must be fastened at the joints with metal or plastic staples by sewing. However, it is more economically feasible to connect the layers by welding, because the overlap in this case can be equal to only 10 cm. In this case, the seam is more durable. For this, the edges are heated with a burner, and a second segment is superimposed on top. The seam is pressed down for a while. Under the influence of thermal force, the material will not lose its properties.
Backfill and compaction
The next step is towill cover with soil or sand geotextile. If the bulk layer is planned to be formed using special equipment, it is important to control that the sheets do not catch on the wheels. The material must not be displaced. The final step will be surface leveling and tamping to secure the geotextile and prepare it for further construction work.
Geotextile cost
The price of geotextile will vary depending on its characteristics and the size of the web. By purchasing Dornit non-woven material with a density of 300 g/m2, you will pay 35.4 rubles. per square meter. In this case, we are talking about a canvas with dimensions equal to 3x50 m.
If the parameters increase to 3x100 m, and the density decreases to 200 g/m2, then you will have to pay 24.2 rubles for the material. per square meter. Technohaut Geo non-woven geotextile, whose density is 60 g/m2, costs 756 rubles. for one roll, the dimensions of which are 1.6x43.75 m. You may also be interested in the price of geotextile, the density of which is 130 g/m2, and the dimensions of the roll are 1.6x43.75 m. Cost - 1554 rubles. per piece.
Conclusion
Geotextiles today are widely used in laying the foundation. This material has many positive features, among them it is necessary to highlight moisture resistance and resistance to mold and fungus. The material is resistant to aggressive environments, does not absorb moisture, and, if necessary, allows you to strengthen weak soils.
The canvases laid under the foundation perform a reinforcingfunction, retain large fractions that could damage the waterproofing, and also do not allow water to accumulate in places where it could damage the structure. As a result of the use of geofabric, it is possible to lay a foundation that is highly reliable and especially dense.
