The Effect of the Change in Composition Ratios and Additives on the Workability and Rheology of Self-Consolidating Concrete

Although self-consolidating concrete (SCC) has been developed for about 2 decades, but its widespread use is still limited. One of the most important factors is the lack of complete recognition of the properties (especially in fresh state) of this concrete and the effect of changing the composition ratios and additives on its performance. In the present study, 7 mixtures has been designed based on a mixture (by changing the composition ratios and the use of additives),and the three main fresh properties (filling and passing ability and segregation resistance) and rheological parameters (by rheometer) have been measured. The results of this study show that reducing the amount of paste volume causes the most improper changes to SCC fresh properties. According to the results of rheograph, the simultaneous increase in plastic viscosity and yield stress has reduced the segregation resistance and reducing yield stress and plastic viscosity could be suitable for improving the concrete stability. On the other hand, based on the results of this study, in self-consolidating concrete with the same water-to-cement ratio, the simultaneous increase in yield stress and the plastic viscosity indicates the lower compressive strength of the concrete.