Quantitative Image Analysis of Concrete-Epoxy Interface Failure Mode Subjected to Sustained Load and Temperature

초록

In this study, we aimed to develop an image analysis method for evaluating the fracture surfaces of concrete-epoxy interfaces (CEI). CEI is formed when an externally-bonded fiber-reinforced polymer (FRP) system, which is considerably influenced by environmental and loading conditions in service, is applied. CEI debonding failure is characterized into one of three possible modes: cohesive failure in the concrete (CC), interfacial failure (IF), and cohesive failure in the epoxy (CE), using the developed image analysis method. Quantitative image analysis with a set of rules for failure mode classification enabled the correlation of the CEI failure mode with bond performance, such as the fracture energy three-point bending specimens and single-lap shear specimens’ peak pull-off force. The results reveal a robust failure mode and bond performance correlation. Extended periods of sustained loading decrease the bond performance and shift the dominant failure mode from CC to IF. © 2022 by Korea Concrete Institute.

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