23 April 2018
Geotextile to prevent road cracks
Reflective cracking – cracking from an existing crack – on roads is common on Indian roads. It decreases the life of asphalt roads. Vehicle tyres experience more friction due to these cracks. At times, this can even lead to accidents. Reflective cracking is costly in terms of fuel and lives.
Image by Bidgee via Wikimedia Commons
An overlay of geotextiles such as coir and jute, before laying asphalt, has proven effective to retard these cracks, dissipating stress accumulation by changing the direction of the cracks. However, qualitative and quantitative evaluation of the use of the textile materials is not available.
Recently, scientists from the IIT Madras tackled this problem. They studied the tensile strength and the asphalt retention capacity of coir, jute and glass grid. They used woven and non-woven fabric. And found that non-woven fabric was better at retarding reflective cracking. This was because the non-woven fabric had a large number of voids, resulting in larger absorption of asphalt. Among the different non-woven geotextiles, they concluded that SGT, a composite of glass grid and non-woven textile, had the highest asphalt retention capacity.
They also studied the thermal retention of these fabrics. Jute and coir fabrics decompose at around 240° C. During the construction of pavements, asphalt blocks only attain a maximum temperature of 180° C. This makes jute and coir stable enough for use in pavement construction.
Along with other results from earlier studies by these scientists, this report proves that geotextiles help retard cracks. These geotextiles are easily available and economically feasible . Since all these results were limited to the lab only, practical application of the geotextiles on actual roads needs to be done to compare effects on retardation of reflective cracking. This is an important comparative study and is definitely beneficial to road construction companies.
J. Materials in Civil Engg., 30 (4): 04018036 (2018)