This study investigated the engineering performance of cement-treated laterite soil blended with quarry dust (QD), specifically evaluating the sensitivity of these mixtures to compaction delay. Compaction delay times were investigated at 1 hour, 3 hours, and 5 hours. The untreated laterite soil was classified as unsuitable for pavement applications due to excessive plasticity and low soaked California Bearing Ratio (CBR) values below 30%. Experimental results showed that the synergistic addition of cement (0–10%) and QD (0–50%) significantly enhanced the geotechnical properties. The optimal mixture (50% QD + 10% Cement) achieved an increase of 9.32% in maximum dry unit weight, a 1325% increase in soaked CBR (228%), and a 449.9% increase in Unconfined Compressive Strength (UCS) relative to the natural soil. However, compaction delay exerted a profound detrimental impact on mechanical properties. Increasing the delay time to 5 hours resulted in a 6.82% reduction in density, while CBR and UCS values reduced by up to 53.9% and 29.5%, respectively. Correlation analysis revealed that this degradation is primarily driven by an increase in porosity resulting from the hydration of cement before compaction. Predictive power-law models were developed by integrating the porosity/volumetric cement index (η/ C iv a ) with delay time parameters. While some mixtures compacted within 1 hour remained viable for pavement base or sub-base courses, those delayed by 5 hours failed to meet standard specifications. The study concludes that for effective stabilization of laterite-quarry dust matrices, compaction delay should strictly not exceed one hour to preserve structural integrity and load-bearing capacity.
Ubani et al. (Fri,) studied this question.