Effect of aggregate-binder proportion and curing technique on the strength and water absorption of fly ash-based one-part geopolymer mortars

Abstract

Abstract This paper This paper investigated the effects of binder-aggregates proportion on the performance of one-part geopolymer mortars. High calcium fly ash together with sodium metasilicate have been utilized as the binder, the powdered sodium metasilicate activator was kept at 12% by weight of the fly ash. Three types of mortars were produced with a different binder to fine aggregates proportions (B: A) of 1: 0.5, 1:1, 1:2. The strength properties of the one-part geopolymer mortars (OPGM) which comprises compressive, flexural, splitting tensile strength and water absorption have been investigated. At 28 days of outdoor curing, the OPGM exhibited compressive strength of 50 MPa and 43 MPa at ambient curing. The flexural strength of the OPGM represents 16 – 17 % of its compressive strength. Regardless of the curing techniques, the strength properties of the OPGM is almost the same. The optimum OPGM was found to be at 1: 0.5 binder-aggregates proportions at outdoor curing.