Comparative analysis of cement and lime modification of Ikpayongo laterite for effective and economic stabilization

Abstract

Some geotechnical properties of laterite obtained from Ikpayongo treated with 2 to 10 % cement was compared with the same laterite treated with 2 to 10 % Lime, to determine the most suitable modifier for effective and economic stabilization. Modification potential was assessed using Atterbeg's limits test, while California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were used to ascertain strength gain with additives concentration. The plasticity index of the natural laterite reduced from 16 % to 7 % and 4 % respectively, when treated with 10 % cement and lime respectively. 7 day UCS value of laterite increased from 534 kN/m2 to maximum values of 1255 kN/m2 and 1090 kN/m2 respectively, when treated with 10% cement and 10 % lime respectively. California bearing ratio (CBR) value increased from 28 % to 135 % and 100 % when treated with 10 % cement and lime respectively. Based on results obtained from the study, treatment of Ikpayongo laterite with 6 % cement or 4 % lime will effectively modify it for economic stabilization. The use of 4 % lime is recommended for modification of Ikpayongo laterite, as the use of excess cement might lead to cracks in the stabilized layer, even though economic analysis is in favour of the use of cement. Results of tests from the study will serve as a guide in the selection of an appropriate modifier for effective stabilization of laterite for roadwork.