Effect of seawater on the workability, adsorption, dispersion and compressive strength of cementitious materials incorporated with polycarboxylate superplasticiser

Abstract

The shortage of fresh water obviously limits the development of the construction industry. The aim of this study is to investigate the possibility of using seawater in building concrete. The effect of seawater on the workability, adsorption, dispersion and the compressive strength of cement pastes incorporated with two types of polycarboxylate superplasticisers (PCE) was studied. In addition to examining minislump and compressive strength, water film thickness, adsorption amount and adsorption layer thickness were investigated as well to explore the mechanism. The results showed that, compared to tapwater (TW), the minislump of PCE incorporated cement paste was reduced by mixing it with seawater (SW). Moreover, although the seawater increased the compressive strength of cement paste without PCE, the addition of PCEs reduced the compressive strength of cement pastes mixed with both TW and SW. The replacement of SW to TW increased the adsorption amount and while it reduced the thickness of adsorption layer and water film.