Effect of coral powder on the properties of cement-based materials

Abstract

In the construction of offshore engineering, a growing number of coral sand and coarse aggregate is used as concrete aggregates in the local construction. Thereupon, a lot of coral powder is left as a solid waste. This work is an attempt to study the potential of the coral powder replacing part of cement as supplementary cementitious materials. The flow properties of fresh cement paste with coral powder were studied, as well as the mechanical properties of hardened cement paste. Experimental results show that the fluidity of cement paste blended with coral powder decrease with the dosage of micro coral powder, due to its high water demand and high adsorption of polycarboxylate superplasticizer (PCE). Replacement of cement by coral powder have positive effects on the cement hydration and mechanical properties of cement paste at early ages. However, at the curing age of 7 days, the addition of coral powders deceases the strength of cement paste regardless of replacement levels.