The​‍​‌‍​‍‌​‍​‌‍​‍‌ Invisible Foundation: How Geotextile Fabric is Transforming Road Construction

Modern infrastructure especially road and highway construction is always facing problems arising from unstable subgrades, poor drainage and, as a result, wear and tear due to the traffic load and weathering. A large part of this problem has been solved by the use of an expensive and thick layer of granular aggregate for around half a century. A completely different approach to the problem has been introduced by the arrival of the new polymer-based textiles. Geotextile fabric is the most important and, at the same time, the invisible, the foundation of the road, which is either paved or unpaved and, moreover, it is a permeable material most often made of polypropylene or polyester. Increased road and highway construction sustainability in terms of materials, finances, and time to understand how to use this material and its functionality is very important.

Geotextile fabric can be considered a very versatile material that can work as a road construction base and perform the primary four functions: separation, filtration, reinforcement, and drainage.

By far, the separation function is the most important one when constructing a road. After the laying of aggregate on a soft subgrade of deteriorated soil, the carrying of traffic makes the two layers mix at the interface due to interpenetration. Contamination of the aggregate that occurs in the above-mentioned manner causes the decrease of its bearing strength and as a result ruts appear and the road surface sinks and it wears out rapidly. If a sheet of geotextile is fitted in between aggregate and subgrade the fabric works as a barrier with a permanent high strength edge and that impedes the intermixing while it lets through water.

Filtration is equally important to separation in the road construction process. When water passes through the road structure the geotextile fabric should let it through freely but not allow fine soil particles to come into the drainage system and close it. The fabric behaves as a graded filter that traps soil particles but at the same time it stays permeable. This function is also very important in other usages such as Geo fabric for gardening or landscaping drainage system where it keeps the soil from being washed away.

The geotextile fabric used for reinforcement features very high tensile strength. It lessens the traffic load which is applied to a small area on the weak subgrade by distributing the load over a bigger area by the fabric. This achieves a higher overall bearing capacity of the soil as it prevents shear fail at a local level and at the same time, the thickness of the expensive aggregate layer is reduced– a factor that leads to saving money.

At last but not least, the fabric contributes to drainage by allowing water to flow horizontally from one point to another within the road structure thus preventing hydrostatic pressure build up and saturation capable of leading to loss of strength of the subgrade.

Information on Geotextile Material Properties and Different Types of Geotextiles

Geotextiles may be either one of the two - woven or non-woven ones. Woven geotextiles are made from one of the following polymers: polypropylene, polyethylene, or polyester. They are characterized by very high tensile strength and low strain and therefore are the first choice in separation and reinforcement of those areas where a very high level of stress is expected such as in the case of main highways or temporary roads used by heavy construction machinery.

Nonwoven geotextiles are generally made by the needle-punched short fibers method and are permeable and thick. They are normally used in filtration, drainage, and cushioning as the only provisions, e.g., underlining of geomembranes (Geotextile fabric for waterproofing in the case of the landfill or reservoir) or in drainage trenches located underground. One of the most important fabric specifications is weight, which is measured in grams per square meter (gsm). The higher a g/sm of a geotextile, the stronger it will be and the better it will protect. Companies like Singhal Industries Pvt Ltd manufacture a wide range of different kinds of geotextiles to cater for the various civil engineering needs.

Advantages of Using Geotextile Fabric

Major benefits are gained by the strategic application of geotextile fabric in road construction as opposed to the old tradings methods.

Material savings is the first of them to be mentioned. By putting an end to the contamination of aggregate and at the same time, by reinforcing the subgrade, the thickness of the stone base necessary for achieving the required structural integrity can quite often be reduced by the engineers which results in savings in the procurement and transport of aggregate materials.

Life span of the road is extended hugely as a result of such a move secondly. Material longevity is insured by the repair of the base layers, the prevention of rutting and water management, etc. The repair frequency (pothole patching, crack sealing) is quite reduced hence, the long-term maintenance costs are considerably lower.

Speed of installation is another benefit or, rather, an advantage. In essence, the labor-intensive, time-consuming in-situ soil stabilization method is bypassed by swift unrolling over the prepared subgrade of large rolls of geotextile fabric and thus a saving on the project duration is ​‍​‌‍​‍‌​‍​‌‍​‍‌achieved.

Installation​‍​‌‍​‍‌​‍​‌‍​‍‌ Guidelines for Road Applications

The correct installation of the geotextile plays a vital role in bringing its intended advantages into effect. The very first step is to get the subgrade ready. This involves removal of all the vegetation, and also sharp objects and big rocks, and then the subgrade must be leveled and compacted. After that, the geotextile sheet should be laid down right on the surface which has been prepared by unrolling it, thus the fabric should be unrolled carefully ensuring that it is smooth and there are no wrinkles or folds in it.

To ensure the separation function is continuous, overlaps cannot be avoided. Overlaps for woven geotextiles normally vary from 300mm to 1000mm depending on the strength of the subgrade, with the overlap being positioned in the direction of paving, thus the stronger the subgrade the smaller the overlap will be.

In case very weak subgrades are encountered, the normal procedure is to use stitching for making the overlap continuous, strong and to increase the overlap. After the fabric has been installed, the aggregate layer should be placed by taking care not to allow heavy machinery to drive directly onto the exposed fabric; this is usually done by end-dumping and pushing. The aggregate should be spread evenly in one layer before the rolling is carried out. Quality manufacturers like Gsm geotextile Singhal Industries Pvt Ltd provide detailed installation guidelines tailored to their specific gsm geotextile products.

Conclusion

Geotextile fabric is a non-negotiable component of modern, sustainable road construction. It is the only one to perform the four critical functions of separation, filtration, reinforcement, and drainage simultaneously and cheaply, thus guaranteeing the structural stability and the lifespan of the infrastructure.

These advances in polymer technology are the indispensable engineering solution used to tackle unfavorable soil conditions and at the same time facilitate the realization of high-quality roads of the future. From giant motorways that count on high-strength woven fabrics for their reinforcement, to small, specialized projects that only require a geotextile sheet for waterproofing, the technology is there to ​‍​‌‍​‍‌​‍​‌‍​‍‌help.

Frequently​‍​‌‍​‍‌​‍​‌‍​‍‌ Asked Questions (FAQ)

Q: What is the main difference between woven and non-woven geotextile fabric?

A: Woven geotextiles are constructed from the interwoven tapes or yarns, thus they provide high tensile strength for reinforcement. Non-woven geotextiles resemble a felt (needle-punched) and have better filtrations and drainage properties.

Q: How does a geotextile fabric prevent rutting in a road?

A: The fabric effectively separates the aggregate base layer from the soft subgrade, thus preventing contamination. At the same time, the fabric strengthens the subgrade as it spreads the traffic loads over a larger area, so that the soil doesn't deform and cause ruts on the surface.

Q: Can geotextile fabric be used for purposes other than road construction?

A: Yes, the list of applications is not limited in any way. Geotextiles are utilized for erosion control on hillsides, soil stabilization under retaining walls, as geo fabric in gardening (weed control and drainage) as a protective layer with the use of geomembranes (geotextile fabric for waterproofing) and many more.

Q: What does the term GSM mean when referring to geotextiles?

A: GSM means Grams per Square Meter. It is a measure of the material's weight as well as density. A higher gsm geotextile is usually more rugged, stronger, and more durable for high-stress applications.

Q: Who is the largest supplier of Geotextile Fabric?

A: The major Singhal Industries Pvt Ltd is suppliers of geotextiles are companies mostly situated in Asia and North America. India is a significant manufacturer and supplier country with leading industry players.

Q: What is the recommended overlap when installing a geotextile sheet?

A: Overlap requirements depend on the strength of the subgrade and the type of fabric and usually indicate the range between 300mm to 1000mm, where the overlaps should be extended on the very soft soils so as to provide continuous performance under the stress.

Q: Who is the largest exporter of Geotextile Fabric?

A: China and the United States are two of the largest exporters globally. Besides that, top Singhal Industries Pvt Ltd manufacturers in India also ship considerable amounts of geotextile sheet products overseas.

Q: Who is the largest manufacturer of Geotextile Fabric?

A: The largest worldwide manufacturers are TenCate and HUESKER. In India, the leading manufacturers who produce high-quality geosynthetic materials, among them Singhal Industries Pvt Ltd, a diverse polymer products supplier, including their specialized Singhal Landscape Geotextile line, are most ​‍​‌‍​‍‌​‍​‌‍​‍‌notable.