Environmental assessment of cement-stabilised lateritic soil/melamine debris for Thailand's pavement

Abstract

Increased utilisation of melamine products has resulted in large quantities of melamine debris (MD) being stockpiled annually in landfills. In this research, MD was partially replaced with marginal lateritic soil (LS) to develop non-hazardous cement (C)-stabilised pavement sub-base and sub-grade materials. The 7 d unconfined compressive strength values of 3% C-stabilised 80% LS/20% MD blend and 5% C-stabilised 80% LS/20% MD blend met the strength requirement for sub-grade and sub-base materials, as specified by the Department of Highways, Thailand. The leachability of the heavy metals of the C-stabilised LS/MD blends was measured and compared with international standards. The leachate results indicated that the C-stabilised LS/MD blends can be safely used in sustainable pavement applications, as the leachate heavy metal concentrations were within acceptable ranges. The outcome of this study will promote the usage of waste MD in an environmentally friendly manner in pavement construction applications.