Calcined Shale and Palm Oil Fuel Ash as Partial Replacements for Calcium-Based Binders to Enhance Compaction Properties of Marine Clay

Abstract

ABSTRACT Marine clay is a problematic soil; therefore, its properties have been improved by mixing calcium-based binders, with reinforcing components. However, these materials exhibit many shortcomings, and better options are sought. Calcined shale (CS) is frequently used in concrete as a supplementary cementitious material, but it has not yet been used in soil stabilization. This study investigates the partial replacement of lime in marine clay treatment with CS and palm oil fuel ash (POFA). This study comprises two parts. In Part (1), POFA – lime-treated marine clay was assessed to determine the optimum proportion of POFA. In Part (2), CS – POFA – lime-treated marine clay was evaluated to determine the optimum ternary blending mixtures through many tests. Results of Part (1) indicate that the optimum proportion of POFA is 5%. In Part (2), CS exhibits effective enhancement in the properties of marine clay, and the optimum mixture was 10% CS, 5% POFA, and 3% lime. When lime content was reduced from 5% to 1% through replacement with CS, maximum dry density and optimum water content increased by 1.7% and 5.2%, respectively. Hence, CS can be effectively used as a partial replacement for lime in marine clay treatment.