Geotechnical and environmental evaluation of cement-stabilized lateritic soil with wood bottom ash for road subbase

Abstract

This article investigates the characteristics of the marginal lateritic soil stabilized with cement and wood bottom ash (WBA) as subbase materials. A comprehensive methodology involved modified Proctor compaction and unconfined compression tests, supplemented by microstructural analyses, as well as pilot-scale field construction and leachate monitoring. Results revealed that compressive strength increased with WBA content up to 60%, and was further enhanced by higher cement dosages. Compressive strength was inversely correlated with porosity and voids-to-cement ratio. Field monitoring showed that Cr was the only metal consistently detected in leachate, decreasing over time but remaining above permissible limits, indicating insufficient immobilization due to weaker incorporation into cementitious phases. This study highlights the synergistic effects of WBA and cement in improving soil subbase performance while supporting sustainable reuse of industrial by-products.