Influence of initial water, moisture, and geopolymer content on geopolymer modified sludge

In recent years, the development of sustainable construction materials has been the attention of several research efforts. Among those, Portland cement is the one which is of extreme importance due to its high level of carbon dioxide emissions associated with its manufacturing process. In this study, the influence of initial curing time and water content was investigated in an attempt to utilize geopolymer for modifying soft soil (sludge) in the actual landslide area caused mainly by the earthquake or heavy rainfall. Two methods for making specimen applied in this research are sludge conditioning and sludge dewatering methods in consideration of failure strength, failure strain and bulk density of modified sludge using fly ash-based geopolymer at ambient temperature. Test results indicate that the initial curing time has the potential for improving failure strain and strength of modified sludge with the specific condition of soft soil. The result further shows that the initial water content over than 50% total mass of sludge could significantly lead to the decrease of strength performance of geopolymer-based modified sludge. The optimum moisture content of geopolymer modified sludge has strong influence on the amount of geopolymer content and initial water content of the sludge.