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Indexed by:会议论文

Date of Publication:2010-01-01

Included Journals:CPCI-S

Page Number:196-207

Key Words:Concrete; Cohesive force; Compact tension; Cracking; Energy release rate; Fracture toughness

Abstract:The paper presents a model to predict crack propagation in concrete materials using energy-based fracture parameter, wherein fracture toughness in terms of energy release rate was introduced to predict the crack unstable propagation. Due to the presence of the fracture process zone (FPZ) ahead of a crack, energy for crack propagation should partially be consumed to overcome cohesive force acting on the surface within the FPZ. Then, the energy needed for unstable fracture could be estimated based on energy balance principle. Test data from compact tension concrete specimens were used to validate the proposed model. Results of the evaluation indicate that the values of the proposed fracture toughness are independent of the specimen size, and could be used as one controlling parameter for predicting unstable failure of concrete material. Simultaneously, comparison with the double-K fracture parameters in light of stress intensity factor confirms the equivalence of stress-field methodology and energy-balance methodology to characterize crack propagation.