Mechanical Properties of Geopolymer Concrete Containing Low-Alkaline Activator

This paper investigates the mechanical properties of the geopolymer concrete using a moderately low alkali activator. The main objective is to ascertain the compressive strength, split tensile strength, elastic modulus, shear strength, flexural strength and bond strength of the said concrete. The experimental program was carried out by reviewing the variables, namely, the amount of alkaline activator which was set at 4%, and the ratio of alkali activator to fly ash (AA/FA) which was varied from 0.35, 0.4, 0.5 to 0.6. Experimental results show that the geopolymer concrete with 4% alkaline activator could still produce concrete compressive strength above 19 MPa for AA/FA ratio of 0.6 and with treatment at room temperature (33℃). On this basis, the authors derived the empirical equations for geopolymer concrete containing low alkaline activator. These equations were compared with the mechanical property model of geopolymer concrete and that of concrete containing Portland cement. The comparison shows that our model has almost the same trend as the other models.