Journals Proceedings

Abstract

Experimental investigations were carried out for assessing the influence of thermal loading on the cube and cylinder compressive strength of normal and high strength concrete with and without polypropylene fibers. The tests were carried out under two phases of heating and cooling. In the first phase of heating, the specimens were subjected to single heatingcooling cycle with a hold period of 3 hours at 2000C and were cooled in the furnace before testing the specimens for the residual compressive strength. Similar treatment was carried out on the specimens at 4000C, 6000C and 8000C and their residual strength’s were determined. In the second phase of heating and cooling, the specimens were subjected to successive cyclic heating-cooling regime from 2000C to 8000C, with an increment of 2000C and a hold period of 3hrs. After subjecting the specimens to successive cycles of heating-cooling, the specimens were cooled in the furnace and tested for compressive strength. Specimens were also prepared for assessing the strengths at room temperature. It has been observed that with the increase in the thermal loading or temperature, the compressive strength experienced significant losses. The experimental results show that the strength loss is controlled by the composite action of both fiber and concrete. The polypropylene fibers show an increase in the ductility, fire resistance and enhancement of the composite material properties. The results of the present study are useful in understanding the behavior of fibrous concrete properties at elevated temperatures.