Relationship between workability and rheological parameters of self-compacting concrete used for vertical pump up to supertall buildings

Abstract

This paper proposed a workability box of self-compacting concrete (SCC) which is the area where the yield stress and the plastic viscosity of the mixture are suitable for direct pumping up to super tall buildings. The workability of SCC was presented by slump flow, Tv, T500 together with sieve segregation resistance and pressure bleeding test, while the rheology was expressed by the yield stress and plastic viscosity measured by ICAR rheometer. Fly ash was used to replace ordinary Portland cement (OPC) with the content of 15%, 20%, 25% by weight, whereas silica fume used of 4%, 6% and 8% by weight. Water to binder ratio (W/B) was of 0.33, 0.35 and 0.37. The experimental results showed that the SCC mixtures with good workability characteristics had segregation resistance value of 7 to 11% and water emitted volume collected at 300 s from 12 to 20 ml. These values are suitable for the SCC to avoid segregation and ensure the stability together with the homogeneity when directly pumped up to the supertall buildings in the vertical direction.