الفهرس 
1 Chapter 01: IntroductionOnly 14 pages are availabe for public view
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Abstract
Punching shear is one of the aspects to be considered during the design of reinforced concrete flat slabs. Punching shear failure is brittle and destructive initiated by diagonal cracks developed through full slab thickness creating a frustum pyramid in rectangular columns. There are several factors that affect the punching capacity of slabs such as concrete strength, column aspect ratio, boundary conditions, and flexural and shear reinforcement. Design codes deal with punching shear failure in different ways; the Egyptian Code of practice (ECP 203–2020) and American code (ACI 318-19) do not account for the flexural reinforcement in calculations of punching shear, unlike the Euro code (EC2 1992-1-1:2005). In addition, the location of the critical section of punching shear varies among the design codes from half to double the effective slab depth measured from the column face. Design of the slab column joint should account for the effects of axial and shear forces, bending and torsional moments applied to the connection as a consequence of gravity and lateral loads as well as imposed deformations on the slab due to temperature variations, concrete shrinkage, and creep. One of the factors that negatively affect the slab punching shear capacity is the effect of axial tensile stresses. In order to understand the behavior of the punching shear capacity under the effect of axial tension forces, The research line is divided between two researchers to achieve the largest possible aspect of knowledge and understanding. This thesis investigates the effect of axial tensile stresses on reinforced concrete flat slab behavior subjected to punching shear under the cracking concrete limit (fctr). The other researcher investigates the effect of axial tensile stresses on reinforced concrete flat slab behavior subjected to punching shear after exceeding the cracking concrete limit (fctr). The study of this thesis is conducted through an experimental program consisting of four two-way slab specimens with a clear span of 1500 mm in both directions and a thickness of 150 mm. The slabs were subjected to different levels of in-plane tensile forces and tested under a concentrated load up to failure. Through testing, ultimate capacity, steel strains, cracking patterns, and deformation were recorded. It can be concluded that the punching shear strength of reinforced concrete flat slabs subjected to uniaxial tensile stresses is the same as long as the tensile stresses are below the concrete tensile strength.