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ASSESSMENT OF THE COMPRESSIVE STRENGTH OF CONCRETE AFTER EXPOSURE TO ELEVATED TEMPERATURES STRENGTHENED WITH FRP SHEETS
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Abstract
This study evaluates the compressive strength of concrete exposed to elevated temperatures and strengthened with CFRP sheets. A total of 11 cylindrical specimens (150 × 300 mm) were tested, including unstrengthened and CFRP-confined samples with one and three layers. Results show that high temperature reduced compressive strength by about 10.2%. However, CFRP strengthening significantly improved performance, increasing strength from 21.1 MPa to 42 MPa (one layer) and up to 121.5 MPa (three layers). This improvement is mainly attributed to the confinement effect, which restrains lateral expansion and delays crack propagation. Comparison with existing models (ACI 440.2R-17, Wu & Wei, and Pham & Hadi) indicates that all models capture the general trend, while the Wu & Wei model provides the closest prediction. Some discrepancies were observed for multiple CFRP layers due to construction quality. The findings confirm the effectiveness of CFRP in strengthening fire-damaged concrete.
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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Keywords
Concrete, temperature, CFRP, strengthening, model
References
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