Title: Effect of Environmental Conditions on Bond Strength between CFRP Laminate and Concrete Substrate

Author(s): J.J. Myers and M. Ekenel

Publication: Symposium Paper

Volume: 230

Issue:

Appears on pages(s): 1571-1592

Keywords: bond strength; CFRP strengthening; durability; frost effect;moisture; temperature

DOI: 10.14359/14910

Date: 10/1/2005

Abstract:
Limited information is known about the effects of environmental conditionsduring installation on quality and performance of the bond between carbon fiberreinforced polymer (CFRP) reinforcement and substrate material. This research studyinvestigates the effect of surface moisture, relative humidity and temperature on thebond strength between concrete and CFRP reinforcement. Three test methods includinga surface pull-off bond test, a surface shear-torsion bond test, and a flexural test wereused to evaluate the bond performance of the FRP fabric under various installationconditions. Test results revealed that the high surface moisture content, extremehumidity and extreme low temperature can be detrimental to bond strength. Althoughthe high temperature improved the bond strength, it is not recommended because ofdecreased set-time and saturant workability. Based on the results presented in thispaper, a maximum allowable limit on surface moisture content, relative humidity, andtemperature of 4.3%, 82%, and 90oF, respectively, at installation is recommended.