Enhancing the punching performance of two-way RC flat slabs using different configurations of embedded aluminum sections: Experimental program and numerical analysis

Punching occurs in flat slabs around the column as a result of increased column loads, inadequate steel reinforcement, and weak concrete strength. The goal of the current research is to improve the punching resistance of two-way reinforced concrete (RC) flat slabs using internal strengthening with aluminum sections. An experimental program consisting of ten RC flat slabs was prepared and tested to show the effects of three different strengthening configurations (horizontal and vertical, diagonal, or hybrid system consisting of horizontal, vertical, and diagonal sections) on the structural characteristics of RC flat slabs. Also, the effect of the thickness of the strengthening aluminum sections (1.0, 1.5, and 2.0 mm) on the ultimate load, load-mid span deflection responses, stiffness, and absorbed energy of RC flat slabs was investigated. According to the results, the three slabs in the group with the vertical and horizontal aluminum sections had the highest improvements in ultimate loads among all tested slabs of 50.9%, 57.1%, and 68.9% for aluminum thicknesses of 1.0, 1.5, and 2.0 mm, respectively, compared to the control slab. Moreover, a three-dimensional (3D) non-linear finite element model (FEM) was constructed using ABAQUS software. The proposed model was validated using the experimental records. Then, the validated model was used to investigate the effects of the interspacing between the aluminum sections on the ultimate load, load-deflection responses, stiffness, and absorbed energy of two-way RC flat slabs.