Relationship between slump flow and rheological properties of self compacting concrete with silica fume and its permeability

Abstract

The fresh state behavior including yield stress and plastic viscosity of silica fume modified concrete was measured by using a wide-gap viscometer. Bingham model was used to describe the rheology of fresh concrete. Besides, the slump flow was also measured at different time after water addition (TW). The permeation test was then performed after 28days’ curing. According to the experimental results, the rheological parameters were found strongly influenced by the silica fume content as well as TW value. The yield stress increase with silica fume content, while the plastic viscosity decreased at the beginning and then increased. The slump flow decrease with both TW and silica fume content. Furthermore, the relationship between slump flow and rheological properties were proposed. The research also shows that the permeation coefficients of different mix proportions have a larger fluctuation during the early period, especially the control group. After that the coefficients gradually change to be steady and then achieve stable values with the permeated time. At the early permeation durations, the permeability coefficient declines with silica fume content, while in the final, the situation concluded that the permeability coefficient is falling back to a lower value comparing to control group after a rise. It should be noted that the peak value also appears at 4% SF content.