Effect of Fly Ash on Cement Admixture for a Low Plasticity Marine Soil

Abstract

AbstractThe deep cement mixing (DCM) method is one of the popular methods of ground-improvement techniques for enhancing the bearing capacity and reducing settlements of thick deposits of soft clay with high water content. High cement content, of the order of 10 % to 25 %, are often used in practice. To reduce the requirement of cement, an attempt is made in the present study to replace the cement partially with fly ash, as a fly ash–cement composite. Different percentages of Class F fly ash (10 %, 20 %, and 30 %) to Ennore marine clay with different proportions of cement (10 %, 15 %, and 20 %) were added and tested. The optimum clay water content at which maximum strength is achieved was determined for various mixes based on unconfined compressive strength tests. A detailed study showed that addition of 20 % Class F fly ash is effective in all combinations. The behavior of the composite under one-dimensional consolidation was also tested.