Investigation of the Post-Fire Performance and Flexural Behaviour Modeling of FRC Exposed to a Standard Fire

Abstract

Fibers that are used to enhance the residual flexural and tensile strength of fiber reinforced concrete (FRC) are reinforcing materials possessing good mechanical characteristics and properties. The effect of fiber on the flexural strength of FRC at elevated temperatures is limited and hence the present paper studies the influence of fibers (basalt, carbon, glass, polypropylene, polyvinyl alcohol) on strength grades M20, M30, M40 and M50 concrete specimens exposed to elevated temperature for a duration of 30, 60, 90 and 120 min, respectively, with an ISO 834 fire-curve. The objective of the study is to determine the effect of temperature on the flexural strength of fiber reinforced concrete prism and reinforced concrete beam specimens. Past studies have revealed that concrete’s tensile strength is one of the primary factors affected by exposure to higher temperatures, more so than its compressive strength. The residual strength of the specimens was determined after cooling in air, and it was found that carbon fiber reinforced concrete specimens retained more residual flexural strength than the other specimens. The residual energy absorption capacity was analyzed and an empirical relationship was established to find the residual flexural strength in terms of the grade of concrete, the type of fiber and the duration of heating.