STRENGTH PROPERTIES OF FIBRE REINFORCED CONCRETE SUBJECTED TO ELEVATED TEMPERATURE

Abstract

In the present study, it was aimed 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 each target temperature was maintained for 2 hrs 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 fraction i.e. 0%, 1% and 1.5%. The results show a loss in different concrete strengths with increased maximum heating temperature in both plain and steel fibrous concretes. Permeability characteristics of fibre reinforced concrete show better performance than plain concrete. When steel fibres are incorporated at 1% and 1.5% dosage an improvement of fire resistance and crack resistance as characterized by the residual behaviour were observed. The results indicate that the residual compressive, split tensile, flexural and bond strengths of fibre reinforced concrete specimens show 13%, 15%, 43% and 53% more strength as compared to controlled plain concrete specimens.