XFEM and experimental simulation of failure mechanism of non-persistent joints in mortar under compression

Abstract

Experimental and Extend finite element method was used to investigate the effects of joint number and its angularities on the both of the compressive behaviour of joint’s bridge area and its tensile strength. A compressive test condition was used to model the mortar cracks under compression loading. Mortar samples with dimension of 100 mm × 50 mm × 50 mm were prepared. The length of joints was 2 cm. In experimental tests, the joint number is 1, 2 and 3 and its angularities change from 0° to 90° with increment of 45°. Assuming a plane strain condition, special rectangular models are prepared with dimension of 100 mm × 50 mm. Similar to joints configuration in experimental test, 9 models with different joint number and joint angularities were prepared. Also numerical Brazilian test was simulated with the same joint number and joint angularity. The results show that the failure process is mostly governed by the joint number and joint angularities. The both of the compression strengths and tensile strength of the specimens are related to the fracture pattern and failure mechanism of the discontinuities. The strength of samples decreases by increasing the joint number and joint angularities. Failure pattern and failure strength are nearly similar in both of the experimental test and numerical simulation.