New empirical test method to assess Reynolds dilatancy of concrete under free-surface flow

In this study, a new test method was proposed to evaluate the shear-induced volumetric changes, namely Reynolds dilatancy (RD), of sixteen conventional vibrated concrete (CVC) mixtures under free-surface flow. The RD measurements were carried out using a rheometer set-up and different vane-blade types rotating at different speeds. According to the experimental results, the RD values were found in good agreement with the workability of the investigated mixtures. Moreover, the RD values were well correlated with the coupled effect of the relative solid packing fraction of coarse aggregate (phi/phi max) and viscoplastic properties of the investigated CVC mixtures. Furthermore, a strong correlation was established between the rheological properties of the lubrication layer, RD values, and the phi/phi max of coarse aggregate.