Experimental study of the mechanical and durability properties of Slag and Calcined Clay based geopolymer composite

Abstract

ABSTRACT This study focuses on the experimental evaluation of the mechanical strength and durability properties of the geopolymer composites developed at different ground granulated blast furnace slag and calcined clay proportions. The compressive and split tensile strengths of the developed composites were investigated at 7, 28 and 56 days of ambient air curing after 24 h of heat curing at 60°C. The durability properties were investigated using ultrasonic pulse velocity (UPV) test, acid and sulphate attack test using 5% H2SO4 and 5% MgSO4, respectively, and rapid chloride permeability test (RCPT) at 28 and 56 days. The compressive strength and the split tensile strength test results of the geopolymer composite showed improvements over the conventional concrete. RCPT test result shows higher resistance to the chloride ion penetration as compared to conventional concrete both at 28 and 56 days. Acid attack test showed better resistance of geopolymer composite. Water absorption and sorptivity values showed lower water permeability of the geopolymer composite as compared to conventional concrete. The UPV values also improved as the proportion of calcined clay in the mix is increased. A good correlation of compressive strength with UPV and RCPT was obtained.