SYNERGISTIC ACTIVATION OF MANUFACTURED SAND POWDER-SLAG-GYPSUM CEMENTITIOUS COMPOSITES USING RESPONSE SURFACE METHODOLOGY

Abstract

The synergistic effects of alkali and sulfate activators on the flexural and compressive strengths of manufactured cementitious composites comprising slag, fly ash and cement were studied in the present manuscript. The experimental procedure used a central composite design (CCD) for the response surfaces. A regression model was established and tested with the experimental results. The maximum flexural strength, compressive strength, and stone powder content at each age were used as the target values for optimization. The optimal mixing proportion included 14.45% manufactured sand powder and 0.91% gypsum. In addition, the effects of the sulfate activator on manufactured sand powder-slag-gypsum cementitious composites (MSGCC) hydration were analysed after 1 and 3 days, and the mechanism for synergistic activation of MSGCC by alkali and sulfate activators was elucidated/clarified.

Keywords

• 10.13168/cs.2023.0003