“H” Shaped Echelon Joints Under Uniaxial Loading

In this investigation, the failure behaviour of “H” shaped non-persistent cracks under uniaxial load has been examined using experimental tests and Particle Flow Cod (PFC). Dimensions of produced concrete sample was 18 cm × 18 cm × 5 cm. Inside the sample, one “H” shaped non-persistent joints were provided. The angles of the “H” shaped non-persistent joint were 0°, 30°, 60°, and 90° degrees. A total of 12 layouts were considered for pre-existing joints in which the larger joints were 60 cm long and the length of small crack was 2 cm. the opening of crack was 1 mm. Also, the 24 specimens with different non-persistent joints were numerically modeled. Rate of applied axial load to the model was 0.05 mm/min. Tensile strength of concrete was 1 MPa. Model was calibrated by try and error. The outcomes indicate that the crack propagation was mainly controlled by both the angle of the non-persistent joint relative to the loading direction and joint length. The compressive strength of the samples varied with the layout and failure mode of the joints. It was shown that the failure behavior of discontinuities was referred to the number of the induced tensile cracks which were augmented by augmenting the joint angle. The strength of specimens increased by decreasing the angle of joint and joint length. The strength and failure process were similar in both approaches i.e., the laboratory tests and the numerical modeling.