Effect of large broken stone content on properties of roller compacted concrete based on fractal theory

Abstract

The effect of large broken stone content with maximum particle size of 120 mm on the four-graded roller compacted concrete (RCC) is investigated by mechanical properties and freeze-thaw cycles tests. Using fractal geometry, the quantitative relationships of large broken stone content, mechanical behavior, and damage degree of concrete are established, which reveal the influence of large broken stone content on the mechanical properties and frost resistance of RCC. The results of fitting analyses indicate that the compressive strength and the age of RCC are significantly correlated. In addition, the correlations of different mechanical properties of RCC are established. After 150 freeze-thaw cycles, the cross-cutting cracks appear in four-graded RCC, which lead to the failure of samples, while the wet-screened RCC can reach anti-freezing level of F300. The total surface areas of four-graded RCC and wet-screened RCC with different large broken stone contents are calculated by fractal theory, which reveal the positive and negative effects of large broken stone content on the properties of RCC. Based on fractal dimension, the freezing-thawing damage model of RCC was established, which describes the correlation between the damage degree and the total surface area of four-graded RCC.