Experimental Study on Mechanical Properties of Crack-Resistance Mortar based on Alkali-Activated Steel Slag and Fly Ash

Abstract

The generation of steel slag and fly-ash as industrial waste is very high with the development of industry. The accumulation of the waste not only takes the large amount of land but also causes some environmental problems. The intention of this paper is to recycle the steel slag and fly ash to produce cementing materials by alkali-activating. A new type of crack-resistance mortar can then be made by the alkali-activated cementing materials without any Portland cement. Two kinds of sodium silicate used as activator in the study are in solid phase and liquid phase, respectively. Tests of compressive strength and flexural strength were performed to evaluate the properties of the crack-resistance mortar using the two types of activators. Results show that solid activators can obviously improve the compressive and flexural strength at early stages, but become weaker in the later stages .The strength of the mortar using solid activator is increased by 12% compared to liquid activator at the early stages. Moreover, as the water-cement ratio increases, the mortar strength decreases.