Quantitative analysis of the influence of fine aggregate's grading on mortar's rheology

Abstract

In this study, the influence of fine aggregate's grading on mortar's rheology is investigated. Firstly, the non-uniformity coefficient (Cu) and the coefficient of curvature (Cc) were employed to quantitatively evaluate the fine aggregate's grading. The results show that Cu provides a good quantitative description of the fine aggregate's grading and presents a good correlation with its packing density. Following that, the influence of the fine aggregate's grading on mortar's rheology was quantitatively analysed using the Cu parameter, and it was found that the higher the Cu value, the lower the relative yield stress (τr) and relative plastic viscosity (μr) of the corresponding mortar. In addition, the rate of variation of τr and μr with respect to Cu is very small after exceeding a critical value (4.85). This study suggests that, for a packing density higher than a critical value (0.7391), it may be more effective to improve the rheology of mortar by acting on aspects other than the fine aggregate's grading.