AN EXPERIMENTAL STUDY ON IMPROVEMENT OF SPALLING BEHAVIOR OF HIGH-STRENGTH CONCRETE ELEMENTS UNDER FIRE ATTACK

Abstract

The spalling of high strength concrete under f i e attack is discussed in this paper. Two series of f i e tests on reinforced concrete elements were carried out in order to investigate the spalling behavior and effect of spalling on the fire endurance of reinforced concrete elements. The results of the f i e tests on 30 specimens can be summarized as follows: a) the spalling is significantly affected by the water-cement ratio of the concrete, the permeability of the concrete, the amount of steel reinforcement, the f i e intensity and the age of the concrete at f i e exposure, b) the addition of polypropylene fiber into concrete is a good measure for the prevention of spalling and can improve the f i e endurance of reinforced concrete elements, c) the addition of polypropylene fiber into concrete at a ratio of Ikg polypropylene fiber per lm3 concrete reduces the depth of spalling by about 18mrn.