Laboratory investigation of shear strength of pond ash using polymeric and natural fibre geosynthetic as reinforcement materials

Abstract

Polymeric geogrid and woven Coir geotextiles has been considered as an appropriate substitute to geosynthetics for reinforcement because of the better engineering properties. It is generally used for reinforcement of pond ash which can be used in place of soil having lower bearing capacity that will reduce the scarcity of the natural soil, also decrease the cost of construction. In this study, pond ash such as coarse (CP) and Fine (FP) pond ash reinforced with two types of polymeric geogrid (RBG and FBG) and two types of woven coir geotextile (WCG1 and WCG2) were used. Triaxial testing performed on sample of size 100 mm x 200 mm on pond ash reinforced with polymeric geogrid and woven Coir geotextiles having variables such as confining pressure (25 kPa, 50 kPa, 100 kPa and 200 kPa) and number of reinforcement layers (Single, double and triple layer). The results shows that strength of the reinforced models increased significantly with inclusion of reinforcement. With the finer pond ash type, both WCG1 and WCG2 type of coir geotextile showed mixed result with single layer of reinforcement, whereas with multiple layers of reinforcement it was the WCG2 type which showed better results. The strength of reinforced pond ash increased with increase in the confining pressure and number of reinforcement layers. FP generally showed higher strength ratio than that of CP with all the types of reinforcements at high confining pressure except with some coir geotextiles. The coarser pond ash type CP generally showed higher strength ratio than the finer pond ash type FP with polymeric geogrid type FBG at low confining pressures (25 kPa to 100 kPa) with multiple layers of reinforcements.