STUDIES ON THERMAL BEHAVIOUR OF CONCRETE

Abstract

Design of fire resistant structures is of great importance to civil engineers specially in important buildings to avoid structural failure and hence to reduce the losses in case of any unfortunate event of fire. In India steel and concrete is been used as the main element for constructing great structures. Although steel and concrete are non-combustible in nature but at high temperature there is strength reduction and hence the load bearing capacity. Therefore it is very important to know the behaviour of steel and concrete when subjected to fire. To study the effects of fire on concrete and steel members the thesis work has been carried out to get the temperature distribution at various location in steel and reinforced concrete sections when subjected to standard time temperature curve. Since to carry out thermal calculations is tedious and time consuming, thus a software package ANSYS is been used which also supports the thermal analysis. Simple program is also prepared to design RC members. The different aspects which have been studied are as follows: The temperature attained in simple non-insulated and insulated rolled steel beams is found using an analytical approach. For the fire protection of steel structures the use of cement concrete and cement plaster with varying thickness is assessed on particular sections. The temperature variation with respect to duration of fire exposure is been found and the fire performance of different combinations is compared. The results can further help in deciding the thickness of protection to limit the temperature rise on steel section upto a critical temperature limit for a specified duration of fire exposure. Further a simple MATLAB program is made to find the fire endurance of a simple supported RC member based on the provisions given in the code. The same program may be used to design a RC member for a required time period.