Innovative Civil Engineering Material from Sewage Sludge: Biocement and Its Use as Blended Cement Material

Abstract

The disposal of sewage sludge for modern municipalities represents an ever‐increasingly difficult problem. Feasibility studies on the use of sludge to produce cement as a means of ultimate sludge disposal has been initiated. Various properties of the cement, which include chemical compositions and physical properties, as well as mortar strength, are examined. The experimental study indicated that the so‐called biocement that derived from sewage sludge exhibits adequate strength for general masonry work. Laboratory tests were carried out to examine the use of biocement as a partial replacement material for Portland cement. The results show that the biocement can replace up to 30% by weight of ordinary Portland cement without deteriorating the mortar strength. Blended cement with up to 10% replacement level not only shows higher strength than control Portland cement, it also exhibits higher rate of strength development at early ages. Properties of both the biocement and the resulting blended cements are presented in this paper.