Abstract
The low tensile strength characteristics of cement-based materials are the biggest defect restricting their use. Understanding the mechanisms behind tensile cracking shows great significance in guiding the design of cement-based materials and their structures. Hence, a semi-analytical solution of the cohesive zone model (CZM) was developed to describe the failure mode of cement-based materials. This study used the boundary collocation method to obtain the linear elastic solution of stress function that satisfies the boundary conditions, on the basis of the Williams stress function. Subsequently, the semi-analytic solution of CZM was proposed through the weighted integral method by combining CZM and the bonding zone (CZ), and crack opening displacement (COD) obtained from wedge-splitting tests. Finally, the distribution of cohesion and COD were obtained. The results indicated that the COD obtained from CZM showed great agreement with the COD obtained from the tests, with a maximal error of 15.5%. Meanwhile, the cohesion at the CZ tip in CZM has an error of 2.1% compared to the tensile strength of cement-based materials obtained from experiments. These results indicate the high accuracy of proposed CZM in describing the failure of cement-based materials. A new method is proposed to determine the analytical solution of cohesive zone model based on the stress function of fracture specimen and the measurable fracture test data.