Research on the Flexural Performance of Concrete Slabs Strengthened with Steel Beams Using Numerical Simulations

Due to the aging or functional changes of the buildings， the existing floor slab can no longer meet the requirements of bearing capacity and needs to be strengthened. Taking a reinforcement and reconstruction project as the background， this study investigated the influence of different parameters on the flexural performance of a floor structure strengthened with newly added steel beams. Five analysis models were established using finite element software， considering both the connection modes between the steel beam and the floor slab as well as whether the floor surface was strengthened by sticking steel chips in the direction perpendicular to the steel beam. The results showed that under all kinds of strengthening methods， the steel beam and the concrete slab were subjected to bending together， forming a tensile plastic zone on both sides of the beam， and the floor slab exhibited no negative bending moment in the direction perpendicular to the steel beam. When the interface was connected using adhesive or studs， the flexural bearing capacity of the strengthened structure was about 2 times that of the original structure. When there was no adhesive at the interface， or if the adhesive had failed， the yield load of the strengthened structure was still 3.11 times the design load. Setting steel chips on the plate surface in the direction perpendicular to the steel beam had no effect on the bearing capacity. When setting adhesive at the interface， the contact stress distribution between the steel beam and the floor slab was the most uniform， the stress on the anchor bolts at the beam ends was the smallest， and the cooperative working performance between the steel beam and the floor slab was the best， followed by the method strengthened by setting studs at the interface.