Reinforced Concrete Slabs before and after Fire Conditions: Numerical Modeling in Abaqus Software

Fire is a phenomenon that every structure may experience during its useful life. With the expansion of modern urban constructions, the potential of fire hazards and the possibility of their occurrence in the structure has also expanded. What is important is the estimation of the damage caused to the structure due to fire and the residual resistance due to fire, which is very necessary to pay attention to. The main goal of this research is to describe the step-by-step modeling of reinforced concrete slabs in the conditions before and after the fire in Abaqus software. For this purpose, a sample of reinforced concrete slab that was made and tested in the laboratory was selected. After a complete review of the geometrical characteristics of the laboratory sample, loading characteristics and boundary conditions and mechanical characteristics of the materials, first the laboratory sample in the condition before the fire was analyzed in Abaqus modeling software and its results were compared with the laboratory results and next the laboratory sample After the fire conditions are modeled and analyzed. The results of this research show that the Abaqus software has great capabilities in predicting the behavior of reinforced concrete structures after a fire, and it is also easy to observe the temperature increase at any point of the numerical model. In the numerical models, the initial hardness value was higher than that of the laboratory sample, which was due to the connection between the rebars and the concrete in the modeling. Also, in reinforced concrete buildings where a fire occurs, the collapse of the structural members does not occur during the fire, and the building may be able to be reused after this event.

Keywords:

Fire , reinforced concrete slab , residual strength , time-temperature diagram , thermal stress , residual strength