Size Effect on Static Splitting Tensile Strength of Concrete: Experimental and Numerical Studies

摘要

Although there are numerous experimental studies of the size effect on nominal splitting tensile strength of concrete materials being performed, research on effect of specific material parameters involving maximum aggregate size (MAS) and concrete strength grade (CSG) on the splitting tensile strength of concrete materials is relatively rare. This paper investigated the influence of MAS and CSG on macro splitting tensile behavior of concrete materials and the corresponding size effect from both experimental and numerical perspectives. Four groups of maximum aggregate sizes (10, 20, 30, and 40 mm) and three groups of concrete strength grades (C20, C40, and C60) were considered, and a total of 84 concrete cubic specimens with different side lengths (150-350 mm) were tested. A three-dimensional mesoscale numerical method was established and a total of 114 concrete cubic models (with side length up to 600 mm) with different MAS and CSGs were simulated. The results indicate that splitting tensile strength decreases with increasing side length and the downtrend of strength decreases as side length increases. The downtrend of strength in concrete specimens with smaller MAS was more obvious, and the increase in MAS can reduce the sensitivity to the size effect on the splitting tensile strength. Concrete specimens with higher strength grades had more obvious downtrends of strength than did specimens with lower strength grades. The influential mechanism of MAS and CSG on the macroscopic failure behavior and the corresponding size effect of concrete materials were analyzed preliminarily.