Effects of Water Absorption and Retention Performance of Paper Sludge Ash in Combination with Cement to Stabilize Dredged Soil

Abstract

Due to its ability to absorb and retain water, paper sludge ash, a cinder generated from the incineration process of paper sludge, is high potential in used as complement to cement in stabilizing dredged clay soil. In this study, an attempt is made to bring out the effectiveness of combining paper sludge ash (PS ash) and cement in stabilizing dredged clay through a series of unconfined compression tests. Based on the investigated water absorption and retention performance of PS ash, a new parameter, unabsorbed water/cement ratio, W*/C, which is the ratio by weight of the clay–water content that was unabsorbed and unretained by PS ash to cement content, was used to assess the strength development of PS ash–cement-treated clay. It is revealed that the strength of the stabilized clay is governed by the parameter W*/C. The combination of cement and PS ash gives a treatment effect comparable to that of cement and even better for high water content clay. Experimental results show that it is high potential for PS ash–cement-treated clay to be used in soft soil stabilization.