Strength and Durability Assessment of Calcium Carbide Residue Mix on Cement Stabilized Lateritic Soils for Flexible Pavement Applications

Abstract

This study investigates the strength and durability performance of calcium carbide residue (CCR) blended with cement for stabilizing lateritic soils obtained from three locations—Alimini, Ogbogoro, and Ahoada—in Rivers State, Nigeria, for use in flexible pavement construction. Preliminary index tests classified the natural soils as A-2-4 to A-4 materials with specific gravities ranging from 2.67 to 2.71, while compaction tests conducted at varying cement contents (7–12%) revealed an optimum cement content of 9%, producing maximum dry densities of 1730–1735 kg/m³. Calcium carbide residue was subsequently incorporated at 0–30% into the cement-stabilized soils, and compaction, California Bearing Ratio (CBR) at curing periods of 7, 14, and 28 days and durability tests were performed. Results showed that maximum dry density decreased while optimum moisture content increased progressively with increasing CCR content, attributable to particle flocculation and the lower specific gravity of CCR relative to the soil particles. CBR and durability indices, however, exhibited a parabolic trend, peaking at 15% CCR for all three locations, with 28-day CBR values of 125%, 117.2%, and 116.5% recorded for Alimini, Ogbogoro, and Ahoada, respectively. The values recorded substantially exceed the minimum requirement for pavement base course materials. Durability indices similarly peaked at 93 – 98% at the same dosage. These findings establish 9% cement and 15% CCR as the optimum blend for stabilizing lateritic soils, offering a sustainable alternative to conventional stabilizers for flexible pavement construction in tropical regions.