Recently, nonlinear fracture mechanics was applied to analyze concrete structures more accurately, and a new material property such as fracture energy($G_f$) was introduced for its application.
This research includes various strength levels from low-strength of concrete to high-strength, and estimates the relation between the strength of concrete and the fracture energy, especially for the crushed sand concrete. However the experiment for natural sand concrete was also included for the comparison. The wedge splitting test method proposed by Prof. Linsbauer is adopted to investigate the fracture energy in this research.
Fracture behaviors of the natural sand concrete and the crushed sand concrete have the similar trend. In the strength range of 20∼60MPa, the fracture energy and the maximum splitting forces increase with the increase of the compressive strength. In the range of the higher strength, however, although the maximum splitting force increases, the fracture energy decreases with the increase of compressive strength. In conclusion, the fracture energy of concrete is not proportional to the strength of concrete.
