INFLUENCE OF FIRE ON THE MECHANICAL BEHAVIOUR OF CONCRETE SPECIMENS

摘要

In building design it is useful for structural designer to know the effects of fire on strength of various building materials especially on concrete and mortar and structural elements. In the present investigation, an attempt is made to experimentally verify the effects of fire on strength of concrete within a specified duration. The variables of study were mix proportion, water-cement ratio and flame exposure duration. The mix proportions of concrete considered in this study were 1:1:2, 1:1.5:3 and 1:2:4 by weight of ingredients. Three different water-cement ratios were taken for all the mixes. The experimental study reported here was planned to investigate the mechanical behaviour of concrete specimens after exposure to flames for different periods of time. The concrete specimens of M-25 and M-30 grades were subjected to elevated temperatures ranging from 200°C to 1000°C. It was observed that the mix proportion, water-cement ratio and flame exposure duration have significant influence on the concrete strength under fire exposure.