Strength and Toughness of Rubber-cement Stabilized Macadam

Rubber cement stabilized macadam, with properties of strength and toughness, was prepared by replacing similar-sized aggregate with 2.36-4.75 mm rubber particles. The content of the rubber particles was 38%, 57%, 76% and 95% of the total volume of the aggregate. The 7-day unconfined compressive strength test, four-point bending strength test, splitting strength test, and modulus test were carried out using the materials test system (MTS). The results show that the 7-day unconfined compressive strength of rubber-cement stabilized macadam decreases with the increase in the content of rubber particles, and a power function governs the relationship between the two parameters. When the content is below 80%, the 7-day unconfined compressive strength can meet the requirements of the specification. The maximum splitting strain increases with the increase in the content of rubber particles. Based on ensuring the design strength, the maximum splitting strain is 1.9 times that of the traditional cement stabilized macadam. However, the bending tensile strain increases first and then decreases. Based upon the premise of ensuring the design strength, the maximum bending strain is 3.79 times that of the traditional cement stabilized macadam. The splitting dynamic modulus decreases with the increase in the content of rubber particles, and a power function governs the relationship between the two parameters. Compared with traditional cement stabilized macadam, the toughness of rubber-cement stabilized macadam is significantly enhanced, improving its crack resistance as a semi-rigid base material. The addition of rubber particles enables the cement stabilized macadam to increase the failure strain (increasing the fracture energy significantly), adjusts the modulus, and ensures strength. © 2020, Editorial Department of China Journal of Highway and Transport. All right reserved.