Significance of Silica Fume on the Mechanical Properties of Recycled Aggregate Concrete

The various studies related to sustainable concrete construction have encouraged recycled aggregate which is a partial replacement of natural aggregate in concrete mixes. The significance of silica fume (SF) in concrete mix will improve the quality of recycled aggregates in concrete. The Portland cement was replaced with Silica Fume at 0 %, 5 % and 10 %. The coarse aggregate in concrete mix is replaced by 0 %, 25 %, 50 %, 75 %, and 100 % of recycled coarse aggregates (RCA). The compressive strength and split tensile strength of concrete made with recycled aggregates are valuated. Manufacturing of recycled aggregate concrete with silica fume consists of different methods to increase the strength of RCA such as surface treatments, three stage mixing and pozzolanic material. In this paper, the method of using pozzolanic material is studied. In this silica fume is used as pozzolanic material. In this study, the mixing of concrete is done by triple mix method. With silica fume as an admixture recycled aggregate concrete of M35 grade will be manufactured and tested for physical and mechanical properties. These strength results obtained is compared with conventional concrete results. The target strength is achieved at 5 % replacement of silica fume.