Workability retention and compressive strength of self-compacting concrete incorporating pumice powder and silica fume

This paper presents the results of an experimental study carried out to investigate the performance of self-compacting concrete (SCC) mixes, which produced using blended binders containing pumice powder in various proportions. As a volcanic material, pumice possesses pozzolanic properties and can effectively be added to the concrete mixture. The influence of pumice powder on the self-compactibility properties such as slump flow, V-funnel flow, U-box and J-ring flow and compressive strength was investigated. Also, in order to clearly understand the effect of pumice powder on the workability retention of concrete, the slumps were measured with elapsed time. The comparison has been made between SCC with pumice powder to other mixtures with fly ash and slag through tests on fresh and hardened concrete. In all of the mixtures the portland cement was partially replaced from 10% to 50% by pumice, fly ash and slag. The incorporation of more than 30% of pozzolanic materials in the binary blended portland cement mixtures results in a significant decline in the fresh and hardened test results. In addition, to improve the properties of SCC containing pumice, the ternary blended cement replacement with pumice and silica fume (SF) was developed. The results revealed that incorporation of SF substantially enhanced the properties of the mixtures.