Applications of expanded polystyrene (EPS) beads and polyamide 66 in civil engineering, Part Two: Stabilization of clayey sand by lime/polyamide-66

Abstract

While lime is most commonly used as stabilizing agent for clayey sands, this stability can be significantly improved with composition of lime containing polyamide-66 strips. Lime reacts chemically with fine grained material through a process termed cation exchange. The lime creates a surplus of Ca2+ cations that tend to replace monovalent cations. This cation exchange process results in the clayey sand becoming much less susceptible to moisture (i.e. more stable in terms of volume change). Polyamide-66 does not react chemically with the materials being stabilized but increases the particle reinforcement. Hence, we are presenting two broad areas of stabilization mechanisms in this work — chemical and mechanical stabilization. Polyamide-66 is an engineering plastic with a distinguished role in this category of polymers due to its high chemical and mechanical resistance. This paper presents a comparative study with our previous published works on this subject. The mechanisms involved in stabilization, the methodologies applied, the evaluation criteria, and the resulting data have been appraised and interpreted.