Thermo-Mechanical Modeling of High-Strength Concrete Column Subjected to Moderate Case Heating Scenario in a Fire

Abstract

This paper presents a numerically developed computer model to simulatethe thermal behavior and evaluate the mechanical performance of a fixedend loaded loaded High Strength Concrete Column (HSCC), subjectedto Moderate Case Heating Scenario (MCHS), in a hydrocarbon fire. Thetemperature distribution within the mid-height cross-sectional area of thecolumn was obtained to determine the thermal and mechanical responsesas a function of temperature. The governing two-dimensional transient heattransfer partial differential equation (PDE), was converted into a set of ordinary algebraic equations, subsequently, integrated numerically by usingthe explicit finite difference method, (FDM). A computer program, VisualBasic for Applications (VBA), was then developed to solve the set of ordinary algebraic equations by implementing the boundary as well as initialconditions. The predictions of the model were validated against experimental data from previous studies. The general behavior of the model as wellas the effect of the key model parameters were investigated at length in thereview. Finally, the reduction in the column’s compression strength and themodulus of elasticity was estimated using correlations from existing literature. And the HSCC failure load under fire conditions was predicted usingthe Rankine formula. The results showed that the model predictions of thetemperature distribution within the concrete column are in good agreementwith the experimental data. Furthermore, the increase in temperature ofthe reinforced concrete column, (RCC), due to fire resulted in a significantreduction in the column compression strength and considerably acceleratesthe column fire failure load.