الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Actually there isn’t any formula or even a method in the Egyptian Code (ECP 2032017) to determine the punching shear capacity of slab-column sub-assemblage of flat plat structures under fire exposure. The main objectives of this research are to investigate the behavior of Reinforced Concrete (RC) slab-column sub-assemblages of flat plate structures at elevated temperatures, as well as, provide simple formulas to be used by the designers for predicting the punching shear capacity under fire exposure. Numerical simulation enables the understanding of structural performance of flat plates under fire exposure and identifies the major risk of punching failure at slab-column sub-assemblages. An analytical finite element model is developed to study the behaviour of reinforced concrete slab-column sub-assemblages of flat plate structures under fire exposure. The multi- purpose finite element software (ABAQUS 6.12) is employed using 3D 8-node nonlinear heat transfer brick element, for heat transfer analysis and 8-node nonlinear brick element, for structural analysis. Two stages of analysis are carried out to find thermal response of structural members namely thermal analysis and structural (stress) analysis. In the first stage, the temperature distribution over the depth during fire is determined. These temperature distributions are used in the next stage, as the temperature loads, to find the mechanical analysis. The influences of the geometrical and material non-linearity at elevated temperatures are considered based on Eurocode (EC2 1995 Eurocode 2). Analytical models are performed to verify the flexural and the shear behavior of various single span steel beams restraint by four support conditions; pin-roller, pin-pin, fixed-fixed and fixed-slide as well as the behavior of reinforced concrete beams, two-way flat slab and slab-column connection under fire conditions. The results show good agreement comparing with the numerical and the experimental ones. After the verification, a parametric study is carried out in order to study the main parameters that affect the punching shear capacity of RC slab-column sub-assemblages of flat plate structures under fire exposure. Such as, the characteristic concrete compressive strength, the slab thickness, the reinforcing cover, the slab length, the slab reinforcement, and the fire duration. All studied specimens are compared with the Egyptian Code (ECP 203-2017) [100] and the Eurocode 2 (1992) [85]. A simplified method to predict the punching shear capacity under fire exposure is developed. Also a proposal simple numerical formula is presented. This formula can predict the punching shear capacity at elevated temperatures, to be utilized by the designers, taking into account the main parameters that affect the punching shear capacity of slab-column sub-assemblage of flat plate structures. All results are compared with the target ones of ABAQUS. Good agreement is achieved using this formula.