Study of cellular reinforced fly ash under triaxial loading conditions

Abstract

Fly ash produced from thermal power plants as byproduct requires large area for storage. The quantity of fly ash and its hazardous impact on the environment is continuously growing. Tireless efforts are being carried out by many researchers to utilize the fly ash in geotechnical applications. In the present study, the behavior of cellular reinforcement (geocell) in fly ash under the static triaxial tests is emphasized. Triaxial tests were conducted on unreinforced and reinforced fly ash sample of 75 mm diameter and 150 mm height. The cellular reinforcement is made up of used and wasted locally available plastic water bottles. The diameters of the reinforcement used in this present study are 35 and 50 mm, with thickness 1 mm. Four different heights of the reinforcement, 10, 20, 30 and 40 mm, are used for both the diameters to study the effect of cellular reinforcement. The tests were conducted by placing cellular reinforcement in one layer as well as in two layers. Deviator stress–strain patterns due to the effect of cellular reinforcement are studied under three different cell pressures 100, 150 and 200 kPa. Peak deviator stress and shear strength parameters are found increasing with increasing in the height of cellular reinforcement for both the diameters of reinforcement. The 50 mm diameter cellular reinforcement showed high peak deviator stress–strain and shear strength parameters over 35 mm diameter. The placement, number of layers, height and diameter of reinforcement are found to have effect on the peak deviator stress. Finite element simulation is carried out using Plaxis 2D professional version to envisage the failure patterns, horizontal displacement and deviator stress–strain patterns, and results of finite element simulation are found to be in reasonably good agreement with the experimental results.