الفهرس 
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Abstract
This thesis aimed to investigate the punching shear behavior of edge and corner column slab connection with openings. In order to achieve this purpose, numerical study was conducted on forty full scale specimens to investigate the punching shear behavior focusing on five main parameters. The investigated parameters were the opening size and its location, the additional tensile reinforcement at slab column connection, additional top and bottom bars around the opening, the effect of transferred moment from slab to column and the existence of shear reinforcement.
A literature review was provided in Chapter 2 for previous studies to investigate the behavior of slab column connections under the effect of various parameters such as opening size and location, the effect of concrete compressive strength, the effect of column’s size and shape, effect of eccentric loads and the existence of shear reinforcement. The previous studied were focused on the behavior of interior column slab connection, so more studied were needed to investigated the effect of different parameters on the behavior of edge and corner column slab connection with opening adjacent to column in the transferred moment direction.
Chapter 3 presented detailed 3-D numerical models that were modeled using finite element analysis software ABAQUS to validate the analytical results using previous experimental work done by (oukaili and Salman 2014) and (Adetifa and Polak, 2005) . A comparison between the experimental results and the analytical results is provided and discussed in this chapter, this validation was necessary to make sure that the analytical results obtained from the finite element models developed using ABAQUS are reliable and satisfactory and can be used in the work of the parametric study of punching shear behavior of the flat slab with openings focusing on the effect of various parameters.
In chapter 4, detailed 3-D numerical models were modeled using ABAQUS. Forty-two specimens were developed to investigate the punching shear behavior under various parameters such as the opening size and its location, the additional tensile reinforcement at slab column connection, additional top and bottom bars around the opening, the effect of transferred moment from slab to column and the existence of shear reinforcement. Also the finite element models results were provided in this chapter such as, the cracking pattern and failure mode, load deflection curves, the cracking and ultimate loads, concrete strains and steel reinforcement strains.
In chapter 5, the discussion of the finite element models results was provided and the effect of the studied parameters were compared and discussed in this chapter. Also failure loads obtained from the FEM were compared to the predicted punching shear force provided by different codes such as EC2-2004, ACI 318-19, BS 8110 and ECP 203-2020.
6.2 Conclusions
Based on the analytical study using ABAQUS software, the following conclusions were drawn:
• The non-linear finite element analysis models developed using the non-linear finite element analysis software ABAQUS are suitable to be used in the simulation of flat slabs with openings to investigate the punching shear behavior for edge and corner column slab connection under various parameters.
• Increasing opening size leads to increase the deflection at cracking load and decrease the deflection at failure load because of the reduction of slab stiffness. Also, leads to decrease the cracking and ultimate loads resistance of the flat slabs for edge and corner column-slab connection.
• The further the opening from the column the lower the deflection at cracking load and the higher deflection at failure loads. Also, has a significant effect on punching strength of flat slab for edge and corner column-slab connections.
• Additional tensile bars had a significant effect on decreasing the deflection at cracking stage larger than ultimate stage. And had a significant effect on increasing the ultimate loads larger than the cracking loads as a result of increasing steel percentage at slab-column connection.
• Additional top and bottom bars around the opening had a significant effect on decreasing the deflection at cracking stage larger than ultimate stage and this was as a result of providing continuous bars adjacent to the opening to compensate the cutting areas of reinforcement could improve the serviceability of the slab and increase its stiffness. Also had a significant effect on increasing the ultimate loads larger than the cracking loads.
• The additional tensile bars, additional top and bottom bars around the opening and shear stirrups had a significant effect on increasing punching capacity for edge column-slab connection more than corner column- slab connection.
• Transferred moment from slab to column had a significant effect on increasing the deflection at cracking stage, decreasing deflection at ultimate stage and decreasing cracking and ultimate loads, this was as a result of increasing the transferred moment which led to increase the cracks and strains and then the stiffness of slab column connection decreased.
• The effect of the transferred moment was significant as the opening adjacent to column was located at the direction of the application of the transferred moment, specially in case of corner column-slab connection.
• Using shear stirrups was the most effective parameter to increase the punching shear capacity for edge and corner slab column connection then followed by the additional tensile bars and additional top and bottom bars around the opening, and this was a result of increasing the shear reinforcement resisting the punching stresses at the critical section.
• Increasing the number of branches of shear stirrups was more effective than the increase of diameter of stirrups for edge and corner slab column connection ,specially in increasing cracking and ultimate loads.
• EC2-2004, ACI 318-19 and BS 8110 codes provided predicted punching capacity lower than the expected values from the finite element model which was conservative for the predicted failure load except for shear stirrups provided larger values than the expected values for failure loads by the finite element model. On the other hand, ECP 203-2020 provided predicted punching capacity lower than the expected values from the finite element model for all parameters.
6.3 Recommendations
Depending on the outcomes of this study, Further researches are needed to be investigated to accurately predict the real punching shear behavior of edge and corner slab-column connections with openings under the effect of different parameters, such as; columns with different sizes and shapes, effect of different forms of vertical shear reinforcement on flat slabs, different slab to depth ratios, effect of using high strength concrete and lightweight concrete.
Further researches are needed to investigate the effect of transferred moment from slab to column with different directions on punching shear capacity of edge and corner column slab connections with or without opening.