Influence of silica fume and viscosity modifying agent on the mechanical and rheological behavior of self compacting concrete

• Characterization of the effect of VMA and silica fume on the behavior of SCC.
• The role of the VMA and silica fume for the stability and robustness of SCC.
• VMA and SF influence rheology (stability, filling capacity…) in a very similar way.
• Possibility of replacing the VMA by the silica fume and vice versa.

The apparition of a wide generation of mineral powders industrially mastered (like silica fume and limestone filler) and organic products (particularly the superplasticizers and viscosity modifying agent) increases significantly the range of concrete rheological performance.This experimental study is built around the characterization of the effect of viscosity modifying agent (VMA) and silica fume on the rheological and mechanical properties of self compacting concrete. The aim is to find the percentage of silica fume and of VMA that allow to obtain the same mechanical and rheological characteristics. The used rheological tests are the slump flow, V-funnel, L-Box, sieve segregation test, and measurement of the yield stress and viscosity. The mechanical tests are the compressive strength, flexural strength and modulus of elasticity.In this study, we show the role of the VMA and silica fume for the stability and robustness of the concrete. Our experimental results show that, depending on the availability of materials, we can replace the viscosity modifying agent by silica fume and vice versa.