Developing self-compacting concrete with locally sourced materials, a case of Volcanic Ash

Abstract

A wide variety of industrial recyclable by-products have been incorporated in Self-compacting concrete (SCC) in order to enhance its properties and performance, as well as curbing down its cost. Among them, fly ash and slag have been commonly used in developed industrialized countries. However Africa is blessed with volcanic mountains that provide volcanic rocks making it viable to develop SCC with Volcanic ash (VA), a natural pozzolana. The study has attempted to present an experimental study on fresh and hardened properties of SCCs containing VA which was used for partial cement replacement, in comparison with ordinary SCC mixture. The slump flow test for flow-ability, the L-box test for passing ability, and V-funnel test for filling ability were carried out to determine the workability of fresh SCC and compressive strength test at 7days and 28days were performed for hardened SCC. The results indicate that natural pozzolanic materials such as VA can be used to produce SCCs. In addition, the results prove that VA has enhanced the mechanical and rhelological properties of SCC significantly. From the characterization tests carried out, we were able to confirm that VA from Kisoro district had a sum of silca Alumina and iron oxides greater than the minimum required 70% rendering it a good natural pozzolana as stated by ASTM C618.