New diphasic insight into the restricted flowability and granular blocking of self-consolidating concrete: Effect of morphological characteristics of coarse aggregate on passing ability of SCC

Abstract

Self-consolidating concrete (SCC) was simulated as a diphasic suspension. The passing ability of SCC was characterized in terms of restricted flowability and granular blocking due to its non-Newtonian behavior and multiphasic nature. New heterogeneity indices were then defined to evaluate the granular blocking-induced variations of relative solid-packing fraction (φ/φmax) of coarse aggregate (>1.25 mm) and, consequently, the rheological properties of SCC in the J-Ring and L-Box set-ups.In total, 30 low- and normal-paste SCC mixtures and their corresponding fine mortar portions (<1.25 mm) were investigated in this study. The passing ability of the investigated SCC mixtures were found in good agreements with the visco-elastoplastic properties and excess volume of fine mortars, as well as the morphological characteristics of coarse aggregate. According to the established correlations, the most effective morphological characteristics and rheological parameters on passing ability of SCC include the mean diameter and roughness of coarse aggregate, as well as the plastic viscosity and yield stress of fine mortar, respectively. On the other hand, a comparative study on the passing ability of SCC in different set-ups revealed that low- and normal-paste SCC mixtures exhibited higher granular blocking indices in the L-Box and J-Ring set-ups, respectively. Furthermore, the robustness and ANOVA analyses showed that optimizing the paste volume, φ/φmax, and morphological characteristics of coarse aggregate is more effective to enhance the passing ability of SCC than adjusting the water-to-binder ratios and high-range water-reducer (HRWR) dosages.