Penetrability of lightweight aggregate concrete

Abstract

In this paper, a study was conducted on the parameters affecting the sorption of water, chloride ingress and permeability of water into lightweight aggregate concrete. The parameters being studied are the effects of the water-to-cement (w/c) ratio, aggregate type, initial moisture content of the lightweight aggregate, size of the lightweight aggregate, density of the lightweight aggregate, cement paste volume and volume of the lightweight aggregate. Experimental programmes were designed to look into the effects of these parameters on the penetration of water and free chloride ions into lightweight aggregate concrete by water sorption under capillary action in unsaturated concrete, chloride diffusion under a constant concentration gradient, and water permeability under a constant pressure gradient. From this research, it was found that variations in the w/c ratio, cement paste volume, as well as size, density and volume of the lightweight aggregate, have reasonable effects on penetrability properties of lightweight aggregate concrete. The effect of initial moisture content in the lightweight aggregate on properties of lightweight aggregate concrete is not obvious from this research. © 2010 Thomas Telford Ltd.