Modifying a Plastic Clay with Crushed Glass: Implications for Constructed Fills

Abstract

A laboratory study was conducted to evaluate the potential of 9.5mm-minus crushed glass (CG) to improve the physical and strength properties of a high plasticity soil (CH). The model soil used in this study, a kaolinite-bentonite mixture or “model” clay (MC), was chosen to represent the properties of naturally occurring fat clays, as well as to provide baseline data for future comparison of site-specific CH soils. Tests were performed on 100% MC and 80/20, 60/40, 40/60, 20/80 CG-MC (dry CG weight% reported first) blends using the CG previously evaluated by Grubb et al. (2006a). The most significant incremental increases in maximum dry density for standard (2.8 kN/m3) and modified (2.5 kN/m3) Proctor compactive effort and decreases in moisture sensitivity (14 and 12%), respectively, were observed to occur with the addition of 40% CG. By a CG content of 40%, the effective friction angle increased by about 5° while the compressibility decreased by about 33%. Similar improvements of lesser magnitude occurred with additional incremental (20%) increases in CG content.