Performance evaluation of self-compacting concrete containing volcanic ash and recycled coarse aggregates

Abstract

Sustainable development in concrete technology can be achieved via conservation of primary materials and enhancement of the durability of concrete structures. Accordingly, in this study, self-compacting concrete (SCC) was developed economically, using sustainable materials such as volcanic ash (VA) and recycled coarse aggregates (RCA). The flow behavior, mechanical properties, and durability performance were evaluated and compared for the developed mixes. Six concrete mixes with different compositions, including the replacement of ordinary Portland cement and normal coarse aggregates (NCA) with 30% VA and 30% RCA, respectively, were prepared using the saturation dosages of superplasticizer (SP) and viscosity modifying admixture (VMA) obtained from the paste study. SCC could be developed with the selected compositions through a two-stage mixing method, and it was observed that the replacement of NCA with 30% RCA did not adversely affect the mechanical properties. A modification in the microstructure could be observed with the incorporation of SP, VA, and VMA. Further to this, the reduction in the durability properties with the incorporation of VA and RCA was compensated with a ternary mix containing ground granulated blast-furnace slag. In general, the SCC incorporating regional and local materials such as VA and RCA could be used, based on the durability indices developed through this study, and considered as a viable alternative to meet the raw material shortage in Kuwait.