Effect of Polycarboxylate–Ether Admixtures on Calcium Aluminate Cement Pastes. Part 2: Hydration Studies

Abstract

In part 1, the effect of different polycarboxylate ether (PCE) admixtures with Portland-based binder (OPC) and calcium aluminate cement (CAC) pastes has been studied; indicating a low CAC–PCEs compatibility. In this part, 2, the effect of PCE admixtures with different molecular structure on the hydration and microstructural development of CAC pastes has been studied. The findings showed that the PCE admixtures used retarded CAC hydration and this effect is independent of the admixture carboxylate/ester ratio. The results obtained have proven that the presence of PCE admixtures in OPC and CAC pastes does not modify the nature of hydrates formed. However, in CAC pastes, the presence of PCE admixture has an important effect on the amount of hydrates generated, it being 45% lower at the same time than in CAC pastes without admixture.