POST-FIRE REDUCTION OF CONCRETE'S MECHANICAL PROPERTIES AND ITS IMPACT ON RESIDUAL LOAD CAPACITY

摘要

This paper investigates the reduction of mechanical properties of four different light-weight concrete mixes containing expanded clay aggregate in a short time period after exposure to high temperature regime.The research has shown that compressive strength exhibits additional reduction up to 10％20％ 96 hours after being cooled down to ambient temperature.A numerical example of simply supported concrete column exposed to standard fire from four sides is given, illustrating the effects of post-fire strength reduction on residual load capacity.The results obtained indicate that the effect of short-term reduction of the compressive strength of concrete in real structures damaged by fire could have a significant effect on the post-fire load bearing capacity of structures and should be accounted for in the engineering building codes.