Title: Quantitative Image Analysis of Concrete-Epoxy Interface Fracture
Author(s): Yoseok Jeong, Maria M. Lopez and Charles E. Bakis
Publication: Symposium Paper
Appears on pages(s): 46.1-46.14
Keywords: FRP, externally bonded, bond, failure mode, digital image analysis
The objective of the work presented in this paper is to develop an image analysis methodology for evaluating the fracture surfaces of concrete-epoxy interfaces (CEI). The CEI is formed at the interface between epoxy and concrete and is influenced, as is the interface between fiber reinforced polymer composite bonded to concrete, by environmental and loading conditions in service. The developed image analysis methodology was used to characterize CEI debonding failure by one of three possible modes: cohesive failure in the concrete (CC), interfacial failure (IF), and cohesive failure in the epoxy (CE). Quantitative digital image analysis coupled with a set of rules for failure mode classification enabled the correlation of CEI failure mode with bond performance metrics such as fracture energy and lap shear pull-off force. The results show a strong correlation between failure mode and bond performance. Extended periods of sustained loading decrease bond performance and shift the dominant failure mode from CC to IF.