Behaviour of Fly Ash Concrete at High Temperatures

The present study deals with the behaviour of fly ash concrete at elevated temperatures. Concrete specimens of cubes of 100 mm, cylinders of 100 mm diameter and 300 mm height and prisms of 100 x 100 x 500 mm are cast by replacing the cement with fly ash in a range of 30-50% by mass of cement. The specimens are cured for 7 and 28 days, then dried and are exposed to elevated temperatures ranging from 100 to 500 degrees C for a period of 1 and 3 h, to investigate the effect of temperature on compressive strength, split tensile strength and flexural strength. It is observed that the residual compressive strength, split tensile strength and flexural strength of fly ash concrete initially increased with increase in temperature, later decreased with further increase in temperature.