Damage evaluation of fiber-reinforced concrete exposed to elevated temperatures by nondestructive tests

Abstract

The paper presents a methodology fordamage evaluation of fiber-reinforced concrete (FRC) exposed to elevated temperatures of 400 oC to 800 oC. The residual compressive strength fraction of cylindrical FRC specimens with a water–cement ratio of 0.47 and total fiber volume fraction of 1.2% was evaluated for mixtures with variousproportions of steel and polypropylene fibers. The residual compressive strength fraction increased with the increase in the proportion of steel fiber at 400 oC. The residual strength fractions of mixtures with variousfiber proportions changedless with increasedexposure temperature. The effectiveness of visual inspection and ultrasonic nondestructive tests in assessing theeffects oftemperature exposure and the residual compressive strength fraction was evaluated. The experimental results indicate apotential application of the nondestructive tests on damage assessmentof FRC with variousmixture proportions. Anequation for estimating the residual compressive strength fraction based on ultrasonic pulse velocity was developed.

Keywords

• Fiber reinforced concrete
• High temperature
• Residual strength
• Ultrasonic pulse velocity
• Visual inspection