Effect of mineral admixtures on rheology of self compacting concrete

A robust self compacting concrete (SCC), is a fluid-like, cohesive, non-segregating and non-bleeding suspension of aggregates in cement paste which can flow freely through the reinforcing cage when poured at site. Rheological property of SCC is of prime importance for transporting and placing SCC to ensure mobility and avoid segregation. The building industry in Saudi Arabia has started using SCC recently using locally available materials, and lack of robustness; and issues in respect of pumping to higher levels has been observed. This paper presents the results of an experimental investigation conducted on SCC with silica fume, fly ash and limestone powder as mineral admixtures to investigate the robustness of local SCC Slump flow, V-funnel, J-ring and L-box tests were carried out for characterizing the behavior of SCC in fresh state. The ICAR rheometer was used for measuring the rheological parameters, the yield stress and plastic viscosity, of these concrete mixes. Segregation probe test was used for investigating the static segregation. Results indicate that amount of VMA and type and content of mineral admixture play an important role in providing segregation resistance to the self compacting concrete.