Evaluation of waterproofing and epoxy materials on the durability of externally applied carbon fiber reinforced polymers (CFRPs).

摘要

The need for advanced repair systems for structural restoration applications has greatly increased due to increased load demands and the growing number of aging infrastructures. Carbon fiber reinforced polymer (CFRP) composite systems are a practical repair method for a large number of these rehabilitation needs. In order for CFRP systems to be a successful restoration method, the integrity of the bond between the CFRP and the concrete must provide adequate strength for the external reinforcing.;This research examines the durability of CFRP systems through three different studies. The first tested a CFRP composite system bonded to concrete beams coated with a slurry-based epoxy and waterproofing treatment. The use of a slurry-based epoxy with CFRP fiber strips had shown promising results in the past. However, in this research a bond failure occurred for all cases, the least desirable failure mode for CFRP composite systems. The second study conducted tested epoxy coverage rates. Previous research had indicated flexural strength increased as the epoxy coverage increased. For this research, additional epoxy coverage rates were studied in order to determine if the strength increases linearly with the coverage rate. The third study tested the bond development lengths of CFRP systems based on a previously conducted finite element analysis. The analysis showed that as the bond development length increased, the average shear stress decreased in the center of the CFRP section. The results of this research agreed with the analysis and provided necessary information that can be used to predict the bond failure type for each development length.