Residual Mechanical Properties of Fibre Reinforced Concrete after Exposure to Elevated Temperature

Abstract

This study aims to find out the compressive strength, split tensile strength, flexural strength, bond strength and permeability of steel fibre reinforced concrete subjected to elevated temperatures ranging from room temperature to 800°C. The specimens were exposed to a heating rate of 10°C/min and the target temperature was maintained for 2 hours to achieve a thermal steady state. A total of 210 specimens of plain and fibre reinforced concrete were tested under the test program. Crimped steel fibres were employed in the study at three volume fractions i.e. 0%, 1% and 1.5%. The results show degradation in strength properties with an increase in maximum heating temperature in both plain and steel fibrous concretes. However, when steel fibres are incorporated in the mix, an improvement of fire resistance and crack resistance at elevated temperature was observed. The results indicate a reduced deterioration in residual compressive, split tensile, flexural and bond strengths of fibre reinforced concrete specimens as compared to controlled plain concrete specimens when the temperature was increased from room temperature to 800°C. Residual permeability characteristics of fibre reinforced concrete show better performance than plain concrete.