A study on utilization of landfill mined soil like fraction for sustainable reduction in swelling and cracking potential for expansive and marine soils

Abstract

Landfill mined soil like fraction (LMSF) is derived from mining of legacy landfill waste after removal of larger fraction such as construction debris, clothes, plastics and other recyclables, and accounts for significant proportion of the total legacy landfill waste. LMSF has found applications as landfill cover material; however, owing to its large quantity in many cities, there is a need to explore more applications for its utilization. In this context the present study explores the role of LMSF (filler replacement) with/without ultrafine slag, US (primary admixture) and lime, L (activator) in controlling the shrinkage and cracking of marine and expansive soils during drying. The ratio of the area of crack and shrinkage to total area of specimen, defined as crack and shrinkage intensity factor (CSIF), has been utilized for quantification of the cracking and shrinkage characteristics of soils with/without stabilization. Further, the effect of soil stabilization on the swelling potential (viz., free swell index and swelling pressure) has been evaluated for the soils. In the present study, complete crack mitigation for expansive soil has been achieved for the combination: 40%LMSF (<425 μm) + 50% expansive soil + 8%US + 2%L, while for the marine soil it has been achieved for combination: 40% LMSF (<425 μm/<2 mm) + 50% marine soil + 8.5%US + 1.5%L. The study findings are useful in the context of utilizing LMSF with sustainable admixtures for reducing cracking and swelling potential of soils for various infrastructure applications such as natural and stabilized slopes, embankment, canal bed and ponds.