Tensile strength is one of the important mechanical properties of concrete, but it is difficult to measure accurately due to the brittle nature of concrete in tension. The three widely used test methods for measuring the tensile strength of concrete each have their shortcomings: the direct tension test equipment is not easy to set up, particularly for alignment, and there are no standard test specifications; the tensile strengths obtained from the test method of splitting tensile strength (American Society for Testing and Materials, ASTM C496) and that of flexural strength of concrete (ASTM C78) are significantly different from the actual tensile strength owing to mechanisms of methodologies and test setup. The objective of this research is to develop a new concrete tensile strength test method that is easy to conduct and the result is close to the direct tension strength. By applying the strut-and-tie concept and modifying the experimental design of the ASTM C78, a new concrete tensile strength test method is proposed. The test results show that the concrete tensile strength obtained by this proposed method is close to the value obtained from the direct tension test for concrete with compressive strengths from 25 to 55 MPa. It shows that this innovative test method, which is precise and easy to conduct, can be an effective alternative for tensile strength of concrete.

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Testing of concrete panels subjected to pure in-plane shear loading is necessary to elucidate the shear behavior of concrete. However, available data for predicting the shear capacity and behavior of steel fiber-reinforced concrete are rather limited. This study aims to evaluate the shear capacity and behavior of fiber-reinforced concrete made of highly flowable strain hardening fiber-reinforced concrete (HF-SHFRC) experimentally and analytically, respectively, using a panel tester loaded under pure shear and modified compression field theory (MCFT). The test was conducted using a panel test machine at the University of Toronto. The test results of the HF-SHFRC demonstrated strain hardening behavior at tension after the first crack, as indicated by the increase in the shear stress after the first crack in the HF-SHFRC panel. An analysis procedure is proposed for predicting the shear strength of steel fiber-reinforced concrete (SFRC) based on experimental data of the SFRC panels to obtain reliable results. A comparison of results obtained from the proposed analysis procedure and experiments show that it accurately predicted the response of the HF-SHFRC. The proposed MCFT-based analysis procedure can provide valuable insight for understanding the behavior of the SFRC panels under shear loading.

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