Experimental Study to Reinforce The Weak Subgrade Soil For Low-Volume Roads by Coir Geotextile Mats

The construction and maintenance of pavement over the weak subgrade soil become the challenging task to the pavement engineering. One of the major reasons of subgrade failure of pavement is weak subgrade. The weak subgrade soil noticed a Black Cotton (BC) soil. The BC soil subgrade poses several serious problems to the pavement such as rutting, fatigue, reflecting crack and undulation of the pavement. To minimize this problem of pavement, there are many conventional stabilization techniques were adopted and reported. But these techniques are not applied effectively into the pavement to stabilize the weak subgrade. To address this problem, to give the additional strength to the pavement geosynthetics are taken as alternate material for stabilization of pavement. In the present study, an attempt is made in the laboratory with four types of coir mats by using the fabricated mould. The study is conducted in the form of two-layer pavement system. The pavement model layer is prepared as subgrade and sub-base with BC soil and sandy gravel soil respectively. The prepared fabricated mould is tested by using the Wheel Tracking Test (WTT) under moving traffic loading condition. This study concluded that the suitable placement position and the types of coir mats can be affect the performance of the LVRs. It’s also noticed that the suitable coir mats can effectively reduce the deformation, so that it can be used over the weak subgrade to improve the performance of the LVRs