Effect of Silica Fume on Recycled Aggregate Concrete

Abstract

Use of recycled aggregate (RA) in concrete can be useful for environmental protection and in economical terms. Recycled aggregates are the materials for the future. It is a well-known fact that it gives a little lower strength than natural aggregate concrete. Though, if used up to 20% of replacement, it can give almost similar strength as that of natural aggregate concrete. Hence, it is necessary to improve strength of recycled aggregate concrete for higher recycled aggregate content. Silica fume is a very popular material used for strength improvement. Hence, popular mix of 1:1.5:3 was checked with different percentage of silica fume combination; 5%, 7% and 10% of silica fume was replaced with cement and 30%, 50% and 100% of recycled aggregates were replaced with natural aggregate and results were analyzed. Thus a total of nine trials were analyzed and conclusions were derived in detail.

Keywords: Silica fume, recycled aggregates, recycled aggregate concrete