Abstract
Over the year, due to increase in population, socioeconomic activities, volume of wastes generated in the world has increase drastically and these wastes come from agricultural, industrial, construction and commercial activities. One of the alternative options of managing such waste is to investigate the possibility of waste minimization and re-use. The potential economic viability and environmental benefits of using this biomass waste, such as corn cob ash (CCA) as pozzolan in stabilizing soils for road pavement construction in a subtropical region was investigated This research work was aimed at assessing the effect of corn cob ash (CCA) on the stabilization of lateritic soil used as sub-base material in Emevor/Orogun ongoing road construction project in Isoko North Local Government Area of Delta State. In achieving this aim, samples of lateritic soil were collected from Emevor / Orogun approved borrow pit and the corn cob was collected from Ubiaroko corn processing market and other corn roster vendor in Delta State. The soil collected was air dried and divided into six sample and each sample was stabilize using 0, 2, 4, 6, 8, 10% of corn cob ash, cement and combination of both respectively. A statistical design of experiment using a simplex linear programming optimization was used to optimize the proportion of the mixture of the constituent material (corncob, cement, and lateritic soil) used for the study. From the laboratory analyses, the laterite soil was grouped as A-2-4 class soil and a good subgrade material. Compared to the cement stabilization, the Corn Cob Ash (CCA) stabilization reduced the strength of the laterite soil below the subgrade level. Although the combination of CCA and Cement increased the strength of the laterite soil, the cement stabilization results were higher in terms of CBR values. Combination of CCA and Cement to the soil reduced its plasticity, swell potential and permeability and increased its strength. However, compared to Cement stabilization in improving the laterite from subgrade to subbase, CCA and Cement stabilization is uneconomical. From the Linear programming optimization, a 29.77% of 70:30 ratio of CCA and Cement stabilizer was evaluated to achieve a CBR of 30% as compared to 6% Cement that achieve same result. Hence, other biomass combination ratios were recommended.
