Properties of self-consolidating concrete with recycled clay-brick-powder replacing cementitious material

Clay brick is becoming a major demolition waste and causing environmental contamination in China. Recycling of wasted clay brick could conserve natural resources and preserve land from waste filling. In this research, recycled clay-brick-powder (CBP) was used to partially replace Portland cement (PC) and fly ash (FA) in self-consolidating concrete (SCC) mix. The effects of dosage of CBP on the workability, strength, and shrinkage of SCC were investigated. Test results show that partially replacing cementitious material with CBP can reduce the workability of SCC. Compared with the reference concrete, specimens with CBP had higher 28-day and 56-day strength. The specimens containing 1% CBP had the highest compressive strength. Meanwhile, the replacement of CBP to PC and FA could also reduce the shrinkage of the SCC due to the internal curing effect. Based on scanning electron microscope investigation, specimen with CBP had less pores than the specimen without CBP and improved the microstructure of concrete. Hence, CBP had positive effects on the mechanical and physical properties of SCC.