Geotextile specifications, models and main parameters (detailed description)

Geotextiles are a major topic of discussion. Every time this difficult problem is brought up, it feels like there's never enough to talk about it. Firstly, its classification is very broad, and it's an ambiguous name. Secondly, each different classification of geotextiles is creating many other specifications and models. And people mainly talk about two types of geotextiles that are common in engineering projects.

Geotextiles are divided into short-fiber geotextiles and long-fiber geotextiles. Both are respectively produced from polyester staple fiber polyester and polyester plastic particles through unique processing techniques. Their specifications and models range from 100g/㎡ to 1000g/㎡. Take 100 grams of national standard short-filament fabric and polyester filament fabric as examples. The tensile strength of the national standard short-filament fabric is 2.5KN, while that of the polyester filament fabric is 4.5KN, which is much stronger than that of the short-filament fabric.

Geotextiles are roughly divided into four types, namely woven type, nonwoven type, synthetic type and composite type. Among them, woven fabrics can be further classified into hand-woven type, machine-woven type and knitted type according to their production process flow. Geotextile, simply put, is a new type of composite decorative building material. This kind of decorative building material is mainly produced by using relevant composite decorative building materials. It can have strong durability and also has a certain effect of preventing water from getting wet. Therefore, it has been very well applied in many places, especially in some civil engineering fields Among them, all have the most common applications. Geotextiles are used in geological engineering, solving many problems that were previously unmanageable in engineering projects and providing simple new solutions for many problems.

Geotextiles have excellent filtration functions, drainage functions, protective functions, reinforcing functions and safety protection functions.

1. Strong resistance to microbial strains: It is not damaged by microbial strains or insects.

2. Good water absorption: There are gaps between the flat filaments, so it has excellent water leakage characteristics.

3. High strength: Due to the application of plastic flat filaments, it can maintain sufficient strength and length even in wet conditions.

4. Convenient construction: Due to the light and flexible nature of the material, transportation, installation and construction are all convenient. Geotextile model and specification (performance parameters // inspection index values)

5. Corrosion resistance: It can resist corrosion for a long time in soil and water with different ph levels.

The specifications and models of long-fiber geotextiles and short-fiber geotextiles are generally calculated by weight. The geotextiles produced by small mechanical equipment are mostly between 80g and 380g. Nowadays, some well-developed companies in China can generally produce short-fiber geotextiles and long-fiber geotextiles ranging from 100g to 1500g.

The main parameter index values of geotextiles:

Take nonwoven long-fiber geotextiles as an example: How to measure the quality of geotextiles? The key is to look at the following several performance indicators, namely elongation at break, elongation rate, and CBR puncture strength, etc. For instance, the elongation at break of a 400g/㎡ long-fiber geotextile is 20kn/m, the elongation rate is 40-80%, and the CBR puncture strength is 0.56KN.

There are numerous models and specifications of geotextiles. Geotextiles are classified into different types in various ways, but most of the specifications and models of geotextiles are measured in grams per square meter. For example, 300 grams per square meter, 380 grams per square meter, 450 grams per square meter, etc. Geotextiles are mostly made of plant fibers or flat filaments through needling or hand weaving. Due to the diversity of their raw materials, it is impossible to precisely measure their thickness, that is to say, the measurement of thickness is not accurate enough. At present, the standard is based on weight per gram. In the future, the standard will be based on the allowable tolerance breaking strength. The height that can be understood as weight per gram will no longer be dominant. The hard truth of strength.

Overall, even if the classification of geotextiles is as good and detailed as possible, most of them are measured by strength, especially after the implementation of the 2017 standard for short-fiber geotextiles, this has become even more prominent. That is, the weight per unit area in the old national standard has been abandoned, and instead, the allowable breaking strength is used to measure the index value of geotextiles.

Can non-woven geotextile be waterproof

The basic non-woven geotextile (hereinafter referred to as "geotextile") is undoubtedly not waterproof. Its functions are water permeability, reverse filtration and reinforcement. In engineering projects, it is crucial to protect against various chemical substances. Water can seep down while solid substances are isolated on top. In the middle of the waterproof geotextile, there is a layer of anti-seepage geotextile membrane. Before purchasing, it is essential to make sure this is clear; otherwise, it won't be very good to get the right product.

Geotextiles are produced through a unique processing technique using polyester staple fiber polyester or polypropylene fabric and polyester chips as raw materials, and are formed by three-dimensional needling with soil. They belong to a type of polymer geosynthetic material. Due to its fabric-like processing technology, geotextile is also known as non-woven geotextile or permeable geotextile, and is commonly called non-woven fabric. It has strong corrosion resistance and anti-corrosion ability by itself. Moreover, by adding antioxidant auxiliary materials to the raw materials, its UV resistance can be improved. In addition, geotextile has excellent flexibility and tensile elongation performance, making it an environmentally friendly geosynthetic material.

Generally speaking, when people talk about geotextiles, they mean non-woven fabrics. Perhaps in a strict sense, geotextiles can be divided into non-woven fabrics and woven fabrics. Non-woven fabric includes short-fiber non-woven geotextile and polyester fiber non-woven geotextile, all of which are formed through continuous needling processing by fabric-like mechanical equipment. However, woven fabrics include both woven geotextiles and hand-woven geotextiles, all of which are hand-woven by equipment.

The difference in appearance between non-woven geotextile and waterproof geotextile is that waterproof geotextile is fabric, while waterproof board is granular and much thicker than geotextile. Waterproof geotextile refers to the geotextile anti-seepage raw material made by combining plastic film as the anti-seepage board with non-waterproof fabric. In engineering projects, geotextiles are commonly laid out as geotextile mud walls to achieve the actual effect of water outages. Waterproof boards are a kind of anti-seepage material made from high molecular materials and polymers as the basic raw materials. They can not only prevent liquid seepage but also prevent gas evaporation. Due to its high physical and structural mechanical performance indicators such as compressive strength, tear resistance, and puncture resistance, the product features high compressive strength, good expansion performance, large deformation strain rate, corrosion resistance, anti-aging, and excellent impermeability. It can take into account the civil engineering needs such as water conservancy projects, municipal projects, engineering construction, transportation, subway stations, tunnel construction, and anti-seepage, protection, reinforcement, and anti-cracking structure reinforcement in construction projects.

The anti-seepage characteristics of non-woven geotextiles and waterproof geotextiles (anti-seepage geotextiles) are exactly the opposite. They have the properties of water permeability, reinforcement and reverse filtration, and can be used in combination to complement each other's strengths and weaknesses, jointly forming the anti-seepage cushion layer structure of the anti-seepage main body, ensuring the safety and stability of all environmental protection technologies. It can be said to be "low cost, big effect".

Non-woven geotextiles have many advantages:

1) Ventilation

2) Filtering property

3) Heat insulation and heat preservation performance

4) Water absorption capacity

5) Water resistance

6) Elasticity

7) Not messy

8) It has a good touch and is soft

9) Gentle

10) It is malleable and reducible

11) There is no specificity of the fabric

12) Compared with textile fabrics, it has higher productivity and faster production and manufacturing

13) They are cheap and can be produced in large quantities.

The drawbacks are: 1. Compared with textile fabrics, its compressive strength and performance in use are relatively weak; 2) It cannot be cleaned like other fabrics. 3) Plant fibers are arranged in a certain orientation, so they are very prone to cracking at the top corner. Therefore, the key to the recent improvement of production and manufacturing methods lies in the improvement to avoid disintegration.

People often have a misconception about waterproof geotextiles. Their surface looks basically the same as that of geotextiles. If you touch and feel them, you can understand that there is also a layer of anti-seepage membrane on the inside. It is precisely because of the existence of such anti-seepage membranes that geotextiles truly have the function of waterproofing. This point is often overlooked by everyone, and sometimes it is often confused during the entire purchasing process.

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