Estimation of rheological properties of UHPC using mini slump test

This paper reports a method for estimating the rheological properties of ultra-high performance concrete (UHPC) by applying a mini slump test that can be used easily on-site. Computational fluid dynamic (CFD) analysis of the mini slump test within the scope of viscosity and yield stress of UHPC was performed and a simple equation that expresses the correlation between the variation of the spreading diameter over time obtained from the analysis and the rheological properties was proposed. The mini slump test was carried out on four types of UHPC mixtures and the rheological properties were estimated from the proposed equation, and verified by a comparison with the viscosity and yield stress measured directly using a rheometer. The comparison showed that the rheological properties of UHPC could be estimated quantitatively using mini slump test.