Title: Thermomechanical Behavior of Near-Surface-Mounted Carbon Fiber-Reinforced Polymer Concrete Interface

Author(s): Thushara Siriwardanage and Yail J. Kim

Publication: Structural Journal

Volume: 113

Issue: 3

Appears on pages(s): 567-576

Keywords: carbon fiber-reinforced polymer (CFRP); heat; interface; nearsurface- mounted (NSM); temperature; thermal

DOI: 10.14359/51687944

Date: 5/1/2016

Abstract:
This paper presents the behavior of near-surface-mounted (NSM) carbon fiber-reinforced polymer (CFRP) strips for strengthening concrete members subjected to thermomechanical distress (thermal and mechanical loads are applied simultaneously). The focus of the research lies on examining temperature-dependent interfacial responses that control the performance of such a CFRP-strengthening system. An experimental investigation is conducted to study various technical aspects associated with the thermal relaxation, heat conduction, load-carrying capacity, failure mode, and damage characterization of the NSM CFRP concrete interface. Analytical approaches are entailed to generate practical information that can promote use of CFRP-strengthening technologies, based on the two-parameter Weibull function along with probability-based capacity simulation. The thermal relaxation of a polymeric bonding agent influences the transfer of interfacial stresses, including the stress-decrease response time of the interface with temperature. Transient heat flow is apparent across the interface until the strengthening system fails due to the thermomechanical load. The failure plane of the interface is controlled by the progression of heat energy in conjunction with the phase transition of the adhesive. The slip of the interface articulates a thermal hysteresis mechanism when loaded cyclically. The characteristic parameters proposed aid the design of NSM CFRP systems exposed to elevated temperatures.