Improvement of mix design method based on paste rheological threshold theory for self-compacting concrete using different mineral additions in ternary blends of powders

Abstract

This work investigates an improved mix design method based on paste rheological threshold theory for self-compacting concrete (SCC) with ternary blends powder materials. Six batches of SCC and their equivalent paste tests were first performed to test and verify the applicability of the initial mix design method with SCC contains LP (limestone powder) and FA (fly ash). The basic water demand experiments of mortar were used to obtain the packing density of mortar. A total of 21 SCC tests were then conducted to present an improved mix design method. Yield stress and plastic viscosity threshold formulas are modified based on material packing characteristics. The bilinear interpolation method was used to process paste and SCC results. Futhermore, a total of 36 SCC series were conducted to verify the applicability of the improved method. Prediction accuracy formula according to the figure area were introduced to assess the predictive effect of the improved method. Results show that the relative accuracies of the improved method are higher than 78%, while the initial method is no greater than 45%. This improved mix design method is still applicable with SCC contains both LP and FA.