Ceramics-Silikáty 50 (1) 5-14 (2006)

Effect of polycarboxylate superplasticizer on hydration characteristics of cement pastes containing silica fume

M. Heikal, M. S. Morsy, I. Aiad

This work aims to study the effect of the polycarboxylate superplalsticizer (PCS) on the rheology, electrical conductivity, physico-chemical and mechanical properties of ordinary Portland cement (OPC) pastes containing silica fume (SF). The blended cement pastes were prepared from OPC-SF (90 wt.% OPC + 10 wt.% SF). The results show that addition of PCS to the cement blends decreases their electrical conductivity during the early and later ages up to 28 days. In addition, PCS admixture considerably affects the amount of chemically combined water. Compressive strength of OPC pastes is higher than that of pastes containing SF. However, the addition of 0.75-1.5 wt.% PCS brings higher compressive strength values of OPC-SF pastes than those of OPC cement pastes.

Keywords: Superplalsticizer, Electrical behavior, Rheology, Silica fume and Compressive strength