Control of the setting reaction and strength development of slag-blended volcanic ash-based phosphate geopolymer with the addition of boric acid

Abstract This work aimed to evaluate the role of addition blast furnace slag for formation reaction products and strength development volcanic ash-based phosphate geopolymer. Volcanic ash was replaced by 4 6 wt% ground granulated accelerate kinetics. Then, influence boric acid controlling setting kinetics reactions also evaluated. The results demonstrated that competition between dissolution ash-slag particles is main process reaction. has significantly accelerated initial final times, whereas beneficial delaying times. Consequently, it enhanced flowability paste. compressive increased with slag, optimum rate which resulted in 28 d 27 MPa. Beyond percentage, reduced because flash binder does not allow a subsequent their precipitation. binders formed and/or are improvement water stability