Effect of High Temperature on Properties of Reinforced Concrete Structures.

Abstract

Fire is one of the most catastrophic events that can reduce service life of the building. All structures need to be designed to offer an acceptable level of fire safety and minimize the risks structural damage from heat. The effect of thermo-mechanical deformation may lead to failure of the structure. Reinforced Concrete structures offers fair degree of heat resistance and hence can be very reliable in during event of a fire. But it has been shown thorough multiple studies that, steel loses its two third of strength by the time temperature reaches 600℃. Also, despite being reliable fire resisting material, concrete cannot withstand very high temperature. This paper analyzes the effect of high temperature ranging from 200℃ to 1200 ℃ on properties of concrete. A Finite element based numerical study has been performed on an RCC structure to determine these effects. After a detail analysis, it has been found that, when an RCC structure is subjected to high temperature the strength reduction factor ranges from 0.4 to 0.8. Similarity there is a large-scale increase in thermal strain from 800 ℃ and above. Study conducted on HSC and LWC also indicates the reduction is density of the concrete.