Combined effect of sodium sulphate and superplasticizer on the hydration of fly ash blended Portland® cement

Abstract

Combined effect of polycarboxylate type superplasticizer and sodium sulphate on the hydration of fly ash blended Portland® cement has been studied by using different techniques. Water consistency, setting times, non-evaporable water contents, water percolation, air contents, compressive strengths and expansion in corrosive atmosphere were determined. Hydration products were examined with the help of DTA and X-ray diffraction techniques. It is found that the superplasticizer reduces the pore size and its adsorption on cement surfaces is decreased in the presence of sodium sulphate. Mechanism of hydration is discussed.

Keywords

• Portland® cement
• fly ash
• superplasticizer
• sodium sulphate
• hydration