Effects of Partial Replacement of Cement and Lime with some Agrowaste Ashes on the Geotechnical Behaviour of Lateritic Soil

Abstract

In this study, the optimum stabilizer content for a poor lateritic soil intended as subgrade material for a pavement was sought. The natural soil was first characterized and classified and the soil fall into the class of A-6 based on Nigeria General Specifications for Roads and Bridges (NGSRB) AASHTO soil class for pavement construction. The soil was stabilized at three binder points of 4%, 8% and 12% which coincided with specification limits for cement based on NGSRB with the range of 7-11% recommended for soils in the class A-6. The results from the compaction tests and unconfined compressive strength (UCS) tests show that the suitable stabilizer falls within the specified range of 7 – 11%. Binder contents/proportions of 4% RHA, 8% RHA, 8% (50R + 50O), 4% (60C/L + 40R/O), 8% (70C/L + 30R/O), 8% (0C/L + 100R/O), 8% (50C/L + 50R/O) gave the most promising results of MDUW and UCS. In other to carry out a comprehensive investigation of the properties of the soil to determine which of the promising binder contents/proportions would be most suitable as stabilizer for the soil, it was recommended that other qualifying tests of specific gravity, Atterberg limits, CBR, UCS, durability and permeability tests be carried out for these recommended binder contents/proportions.