Modification of Lateritic Soil with Selected Agricultural Waste Materials for Sustainable Road Pavement Construction

Global astronomical rise in the urban population has led to increase in the quantity of waste materials generated in all facets of human endeavour. Indiscriminate disposal of waste materials is fast becoming a serious problem in Nigeria as construction activities remain the primary source for the generation of huge amount of waste materials. Nonetheless, efforts to achieve the sustainability of the environment have led to the investigation of a number of sustainable materials (solid waste materials) as suitable materials for the improvement of lateritic soil, as against the conventional methods of using cement and lime for soil modification. This paper reviewed the effects of rice husk ash, bagasse ash, palm bunch ash and periwinkle shell ash on lateritic soil for road pavement construction. Documented evidences have shown that rice husk ash, bagasse ash and palm bunch ash, which are all processed agricultural waste materials show great pozzolanic potentials, whereas, periwinkle shell ash has good stabilizing characteristics for the improvement of soil for road pavement construction. A review of the comparative evaluation of the chemical composition and the engineering properties of the materials together with those of cement showed that periwinkle shell ash possessed appreciable amount of calcium oxide (CaO) which supports cohesiveness of the pavement materials and shows perfect potentials for improving the soil while the other materials would require some amounts of cement to effectively bind the soil particles to attain improved matrix with lateritic soil. Arising from this overview, the gap in the related literature was leveraged on to give a direction for the potential use of agricultural waste materials for road pavement construction with consideration of their composition, economic and environmental usefulness and likely future developments.