Fire Performance of Bridge Members Retrofitted with Near-Surface-Mounted Carbon Fiber ReinforcedPolymer Composites.

摘要

This report presents a two-phase research program studying: (1) the interfacial response of nearsurface- mounted (NSM) carbon fiber reinforced polymer (CFRP) strips embedded along a concrete substrate at elevated temperatures, and (2) the behavior of NSM CFRP strips for strengthening concrete members subjected to thermomechanical distress (thermal and mechanical loads are applied simultaneously). First phase: two types of bonding agents are used: ordinary and high-temperature epoxies. Residual behavior of the interface, including the characteristics of individual constitutive materials, is examined when subjected to a temperature range varying from 25°C [77oF] to 200°C [392oF]. Test results reveal that residual strength of the concrete and CFRP is not influenced by thermal exposure; however, residual strength of the adhesive is affected. The performance of the interface bonded with ordinary epoxy is better than that of the hightemperature one without thermal distress. The latter becomes superior to the former with an increase in temperature. Interaction between the adhesive and concrete controls interfacial capacity and corresponding failure mode, rather than the individual strength of the materials. Probability-based simulation that complements limitation of the experimental investigation, in terms of sample numbers, was conducted to develop design factors.