STRUCTURAL STRENGTH OF R.C. SLABS SUBJECTED TO FIRE

Abstract

Fire in buildings is quite often. The recent expamples of fire in New Delhi are Ansal Bhawan, Vigyan Bhawan and Kidwai Bhawan. Losses In terms of property are significant. It is, therefore, important to determine the capabilities of structural elements. to resist fire. When fire breaks out in a building, the components which are mainly exposed to fire are the walls and roofs.. Walls are masonry constructions and roofs are generally reinforced concrete slabs. It is a well known fact that bricks can resist fire more effectively than concrete. The problem of fire hazard is more severe for reinforced concrete slabs. It is, therefore, important to know the thermo-structural response of R.C. slabs subjected to fire. The analysis of structural fire resistance is a complicated process because of many variables involved. These variables include fire growth and duration, temperature distribution across the section, change in material properties and influence of load. Incorporation of these variables in the analysis and then the correct evaluation of these elements is a difficult task. However, it is convenient to perform the fire endurance tests to understand the structural behaviour of these elements. In the present study attempts have been made to understand the response of R.C. slabs at elevated temperatures. R.C. Slabs of appropriate dimensions prepared out of M15 and M20 concrete were subjected to different durations of standard severity fire and relative performance of the two types of slab has been studied. Relevant resulted conclusions are presented in the dissertation.