Effectiveness of lowering saturation on residual shear strength of sand stabilized with fly-ash

Abstract

The established cementitious compounds as the pozzolanic reaction product could significantly ameliorate the peak shear strength of stabilized sand with fly ash. However, the enhancement of its residual shear strength has not been known well. In this research, the effects of fly ash percentages, curing times, and saturations, on various compositions, on the shear strength of stabilized sand were observed through direct shear strength tests. The residual shear strength of stabilized sand with fly ash was compared with that of bare sand. The research found that stabilized sand's shear strength increased with fly ash and curing time and decreased with saturation, both at peak and residual state. There is a significant improvement in the residual friction angle, even in a small fly ash percentage, by reducing saturation during the specimen preparation. The useful effect of fly ash bonding remained in the friction angle after the shearing occurrence, showing that the sand stabilization approach with fly ash was effective during and after shearing.