ABSTRACT To evaluate the enhancement effect of CFRP on the mechanical properties of concrete beams, the crack propagation process of CFRP reinforced concrete beams was studied using three‐point bending tests based on digital image correlation (DIC) technology. The evolution of displacement field, strain field, and fracture process zone (FPZ) of CFRP‐reinforced concrete beams were quantitatively analyzed. A novel FPZ evaluation method was proposed and its reliability was validated through theoretical modeling. Furthermore, based on the DIC displacement field data, the stress intensity factors (SIF) at the crack tip were computed and compared with the theoretical value. The test results show that CFRP reinforcement enhances the load‐bearing capacity of concrete beams by approximately 40% while effectively restraining crack development. The proposed FPZ assessment method is in high agreement with the theoretical model (error < 15%). The deviation of the crack tip stress intensity factor calculated based on DIC from the theoretical value is less than 15%. The study confirms that the DIC technique can effectively characterize the crack extension process of CFRP‐reinforced concrete beams. The established experimental‐analytical framework provides both theoretical foundations and practical methodologies for performance assessment of CFRP‐reinforced concrete.
Fan et al. (Sun,) studied this question.