Abstract
This article shows experimental investigation carried out to study the effect of exposure to elevated temperature on concrete. Four concrete mixes obtained using different proportions of ground granulated blast furnace slag (GGBFS) and silica fume (SF) with 43 grade ordinary Portland cement were considered. Concrete cubes of 100 mm size were cast, cured and exposed to different peak temperatures (up to 700 °C) for different heating periods (1, 2, 3 and 7 h) and tested to failure under compression. Before subjecting the heated specimens to compression test, the heated cubes were closely examined for any signs of cracking, disintegration and loss of mass. The concrete specimens with 5% SF do not show any sign of cracks at different peak temperatures, whereas 10% SF cubes split from corners at 425 °C. However, the concrete cubes with 10% GGBFS did not show any sign of cracking even for 7-h exposure to a temperature of up to 500 °C. The mass loss of all concrete specimens increased sharply up to 200 °C, and after that, it increased marginally. The compressive strength of all concrete mixes increased up to 200 °C and decreased with further increase in temperature, with the exception of concrete containing 5% SF which increased even at higher temperatures but at a slower rate.