Determination of typical flexural reinforcement area in negative region of composite beam

Abstract EN

Continuous steel beams with reinforced concrete slabs on their top are more economical and effective than classic RC beam models (Reinforcement concrete beams).

Also, they are favorite in architectural designs due to their less heights, large spans and ideal resistance to deflection.

However, they suffer from several undesirable structural defects, such as local buckling or lateral torsional buckling, so it is necessary to conduct more research and studies on their flexural behavior.

In this paper, a mathematical model is prepared and suggested to simulates several experimental samples of continuous composite beam sections using the ANSYS 14 program, then comparing the analytical results with numerical experimental curves (load - deflection) to adjust the validity and accuracy of this suggested mathematical model.

Typical reinforcement area value and corresponding resisting bending moment were also determined using this mathematical model for several experimental samples.

Furthermore, theoretical formulas have been derived to determine the typical reinforcement area and corresponding bending moment of composite section in negative region, and compare the results of these formulas with the analytical results from numerical model and with values proposed by the codes.

Finally, several userfriendly design curves were developed to help in computing the typical reinforcement area values for the composite section within the negative area for continuous steel beam of symmetric flanges.

Among the most important results reached, is that reinforcement area ratio is not a fixed ratio but rather related to the properties of the steel and composite section and that it is not advisable to use reinforcement quantities greater than the typical value.