Improvement of Deficient Lateritic Soil Using Cement and Calcium Carbide Residue

Abstract

Lateritic soil, obtained from a borrow pit at Lapan Gwari, Minna, Niger State was stabilized with up to 6 and 8% (at 2% variations) of cement and Calcium Carbide Residue (CCR) respectively.Effect of the additives was investigated with respect to compaction characteristics (Maximum Dry Density-MDD and Optimum Moisture Content-OMC) and Unconfined Compressive Strength (UCS). Results of index properties of the soil indicated that it classified under CL and A-6, according to Unified Soil Classification System (USCS) and American Association for Highway and Transportation Officials (AASHTO) respectively. There was a general increase in both MDD and OMC of the treated soil with increase in dosage of cement, while at constant cement content, the MDD and OMC of the mixtures was observed to decrease and increase respectively, with increase in CCR content. UCS was observed to increase as cement content increase, while at constant cement content, the UCS increased to their maximum values at 4% CCR content, after which the strength decreased, indicating 4% CCR content as the optimal. Results of the study showed that 2 and 4% cement and CCR respectively, satisfied the 1710 or 1750 kN/m2recommended in the literature, as criteria for design cement content, which is considered adequate for soil-cement (and now soil-cement-CCR) composite as base course material for highway pavements with light to medium traffic.