Agro–Industrial Waste Blends on the Mechanical Response of Selected Soils

Due to urbanization, it is nearly impossible to construct civil infrastructure without encoun-tering soil materials with poor geotechnical response. In soil re-engineering, the trending practice is the use of supplementary cementitious material with the aim of reducing carbon footprints and construction costs. This has necessitated the usability of integrating the blends of palm oil fuel residue (POFR) and calcium carbide powder (CCP) in the amelioration protocols of two soil materials. The amelioration protocols were implemented by the inclusion of 0, 2, 4, 6, 8, and 10% dosages of POFR and 0, 2, 4, 6, and 8% dosages of CCP at the requisite weight of soil materials. The experimental work was performed in three phases, namely material characterization, mechanical performance, and microstructural testing. Judging from the index performance, black clayey soil (BCS) and reddish lateritic soil (RLS) are clayey materials with a plasticity index of 28.70 and 28.80%, respectively. Concerning the mechanical performance (compaction, California bearing ratio, and durability), the inclusion of the blends of POFR-CCP into the soils (BCS and RLS) activated a positive response and was later validated via means of microstructural tests. This research has shown the potential of blended waste residues in soil re-engineering studies. The study was vividly achieved through a qualitative approach known as scanning electron microscopy and Fourier transform infrared.