Fire Resistance Efficiency of High Strength RC Columns Containing Polypropylene Fibers

Abstract

In order to ensure the fire resistance efficiency of framework members, which were made using high strength concrete, loaded fire resistance tests were conducted using high strength RC columns containing PP (polypropylene) fibers in which the specified design strength (Fc) was increased from 60N/mm² up to 150N/mm².
Our findings were as follows:
1) There was no explosive spalling at Fc60 regardless of whether or not PP fibers were added. High strength RC columns of Fc60 provided 3hours of fire resistive period capacity.
2) At Fc80 to Fc150, explosive spalling occurred when there was no PP fibers mixed in the concrete. As Fc increased, the scale of explosive spalling increased and fire resistive period capacity decreased.
3) The addition of PP fibers had the effect of suppressing explosive spalling. The amount of PP fibers needed to maintain 3hours of fire resistive period capacity is estimated to be 0. 055vol. -% or greater for Fc80; 0. 10vol. -% or greater for Fc100; and 0. 33vol. -% or greater for Fc130 and Fc150.