Mix Proportioning of HSC Using Manufactured Sand

Concrete is used in abundance in construction industry. The concrete mix is proportioned based on the strength requirement. High strength concrete (HSC) is used in multi storied buildings, bridges, bunkers, silos, atomic power plant. Current practice shows that for formulating HSC use of natural sand is common all over sites. But day by day natural sand deposits are decreasing due to tremendous use. Hence some alternative to develop required strength as natural sand is a current challenge. So in order to overcome this problem, efforts are contributed for designing HSC using manufactured sand. In the present study, the attempt is made to design mix for HSC of M70 grade concrete for various water to cement ratios using proper proportion, admixtures, and manufactured sand with required workability. For design mix of HSC, the silica fume (SF) used at various percentage replacement levels i. e.10 %, 12 %, and 14 % respectively with cement whereas superplasticizer (SP) is used at 1 %, 1.2 %, and 1.4 %. Different trial combinations were made using percentage variation of SF and SP with including total replacement of river sand with manufactured sand. After proper curing it is tested in laboratory. The compressive strength results are obtained at lower water to binder ratio i. e. at 0.27.