Experimental test and PFC3D simulation of the effect of a hole on the tensile behavior of concrete: A comparative analysis of four different hole shapes

AbstractIn this article, the effects of porosity and its geometry on tensile features of concrete were investigated, using the Brazilian test and three dimensions PFC model. In the first step, the PFC sample was calibrated by indirect tensile lab outcomes and uniaxial compression test outputs. In the next step, indirect tensile tests were done on the models consisting of various pore shapes. Cylindrical models consisted of internal pores with different shapes such as rectangular, circular, horizontal notch, and vertical notch. The diameter and or the length of these porosity changes in various values, i.e., 10 mm, 20 mm, and 30 mm. Twelve different configurations of samples were prepared by varying the porosity shapes. The mechanical behavior of samples has been provided in form of stress–strain curves at a constant and slow loading rate of 0.05 mm/min for ensuring the static condition based on Newton's first law. Concurrent with numerical simulation, an experimental test was done on the concrete slabs containing different pores. The outcomes showed that porosity geometry plays an important role in the fracturing pattern. It was found that the porosity geometry has potent consequences on fracturing process stress and the value of the UCS for rocks. Numerical simulation shows that fracture energy decreased by increasing the dimension of the defect. Crack initiation stress was close to final stress in vertical notch configuration while the difference between the final stress and crack initiation stress has a high value for horizontal notch configuration. The sharper the hole tip, the faster the progressive failure occurred.Keywords: Pore shapetensile strengthPFC3D Additional informationFundingThis work was financially supported by the Science and Technology Department of Sichuan Province (2023YFH0022); the National Natural Science Foundation of China (52204104); the Open Project of State Key Laboratory of Coal Mine Disaster Dynamics and Control (2011DA105287-FW201905); the Open Fund of Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province (20kfgk01); the Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology (SKLGP2021K009); the Sichuan University postdoctoral interdisciplinary Innovation Fund.