Experimental Investigation on CFRP-Confined Low Strength Concrete after High-Temperatures Exposure

Abstract

Abstract The current research studies the effect of high temperatures on the behavior of low-strength concrete after wrapping it with one layer of polymer carbon fiber(CFRP) for strengthening. Eighty-four specimens were examined, 42 wrapped with fiber CFRP sheets and 42 un-wrapped, where the study was conducted on cylindrical specimens (150 × 300 mm) that were exposed to different temperatures ranging from (100 to 600°C) for 1 and 2 hours as a period of exposure to heat. The behavior of low strength concrete represented by compressive strength, ultrasonic pulse velocity, dynamic modulus of elasticity, and weight loss are the focus of the practical part of the study. The results revealed, the compressive strength of the wrapped specimens increased by (35%) and (49%) when exposed to temperature (200°C) and for a period of one and two hours, respectively, compared to the unwrapped specimens and at the same degree. Also, the external strengthening with CFRP sheets acted as a protective layer for the concrete, which led to an improvement in the behavior of the low strength concrete.