Effect of Cement Content on Strength and Microstructure of Cement Stabilized Clay

Abstract

This paper presents the effects of cement content on the strength development of cement stabilized clay. A qualitative and quantitative study on the microstructure of the stabilized clay was carried out using scanning electron microscope, and mercury intrusion pore size distribution measurements. It is found that the relationship between strength and cement content at a particular water content is divided into three zones: active, inert, and decline zones. The difference in the microstructure of the stabilized samples in each zone is realized by the hydration products and pore size distribution. Initially, strength increases markedly with cement content and becomes inert in the second zone where the maximum strength occurs. The samples of highest strength possess the highest amount of hydration products and the lowest total pore volume. In the decline zone, the hydration products are insignificantly noticed from SEM photos and the total pore volume is larger than that of the other two zones. It is because the water is not significantly for complete hydration and compaction. Thus the large clay-cement clusters with high resistance to compaction are formed, resulting in large pore space.