Optimizing the rheological properties of hybrid fibre reinforced self-compacting concrete with partial replacement of fine aggregate with foundry sand using response surface method.

Abstract

Self-compacting concrete (SCC) is the economical form of concrete widely trusted and practiced today. With addition of fibres the Fibre reinforced SCC (FRSCC) results in improvement of strength and durability properties. The theology of the FRSCC is dynamic and depends on the materials added to it and hence predicting the workability becomes complex. The objective is to obtain a model to predict the workability of a sustainable Hybrid FRSCC (HFRCC). The present study investigates the optimization of HFRSCC with glass and steel fibres and partial replacement of fine aggregate (M-Sand) with foundry sand - a waste material, using response surface method. Slump flow, L-Box, Segregation resistance and V-funnel tests were conducted experimentally in different combinations with percentage of fibres up to 3% and replacement of FA with foundry sand up to 60%. The results are compared with the output of the modelled results. The workability is optimum at 1% steel fibre, 1.5% glass fibre and 25% replacement of foundry sand in experimental study and 0.5% steel fibre, 2.0% glass fibre and 23.5% replacement of foundry sand from response surface model.