Investigation on Spark Plasma Sintering of Calcareous Waste Concrete Powder and Coal Fly Ash

Abstract

This paper aims to fabricate a composite material using calcareous waste concrete powder and coal fly ash (FA) by spark plasma sintering. The effect of FA addition on the mechanical properties of the composite material were investigated. The maximum FA content was 7.5 wt%. The relative density of the composite material was approximately 1.0, independent of FA content. In contrast, the Vickers hardness, flexural strength, and flexural modulus increased with increasing FA content. However, the dispersion state of FA in the composite material was not observed by scanning electron microscopy. Powder X-ray diffraction of the composite material revealed that spurrite and wollastonite were formed identically, independent of FA content. Therefore, FA serves as a reinforcement in the composite material.