Numerical Analysis of Reinforced Concrete Columns Subjected to Fire and Different Loading Conditions

Abstract

This research is to study the effect of fire on the axial bearing capacity and behavior of columnsreinforced concrete.Search includes the study is performed on columns under axial loading with various shapes and with realistic dimensions (square, rectangular, circular, hollow square, hexagonal and hollow hexagonal columns). All samples of columns have a height 4000 mm and the same cross-sectional area, exposed to fire from the all sides to level (300°C and 600°C) for a period one hour using the Finite Element program ABAQUS.

A numerical study of two models, first C1 (reference column) and second C2 (burned at a fire flame at 300°C). The numerical results were compared with experimental results as far as possible, in order to verify the accuracy of the numerical models used. The effect of temperatures depends not only on the intensity and duration of the heat but also on some geometric features such as the location of burning, direction of application of load etc.

In this research, the most common scenario of burning from all direction and application of load in direction of gravity was used. The results of this investigation showed that values of ultimate load decrease when the columns specimens are exposed to fire, Circular column with spiral reinforcement is more resistant to fire due to the stability of dimensions in all directions compare other solid columns and the stiffness was decreased with increasing the temperature.