The University of Baghdad witnessed the public discussion of the doctoral student (Hanaa Abdul-Baset Ali) from the Department of Civil Engineering for his thesis entitled (Performance Of Concrete Slab-Column Connection Strengthening With Steel Collar Under Shear And Moment (. On Tuesday, 5 November 2024, in Professor Khaled Shaker Hall, under the supervision of Asst. Prof. Dr. Mohannad H. Al-Sherrawi.
The aim of the study The present study investigated experimentally and numerically the effect of strengthening slab-column connection with steel collar subjected to concentric and eccentric static loads. The experimental work included nine flat plates with a half scale down two-way for square dimension of (1400*1400) mm and thickness of 100mm, three slabs were designed with 400 mm as a height of column and cross-section of (150*150) mm, they were subjected concentrated load and considered a reference. the findings include that, most useful of strengthening slabs by steel collar especially when increase the thickness of steel collar in both type of load led to efficient in extending the perimeter of failure area so that, the failure mechanism (punching shear) did not change just shifted away from the column’s face.The steel collar make the collapse did not occur suddenly, it gave warning gradually by the increased cracks width. The steel collars increase the perimeter of failure zone therefore the shear strength increases.The specimens were tested with eccentric load decreases the ultimate load capacity on account of the influence of unbalanced moments. The position of cracks took place at one side more than the other in slabs due to effect of eccentricity.The slabs are stiffer when steel collar used, the value of stiffness in flat slab with eccentricity is less than specimens with concentric load.
The following recommendations and proposals for future are: –
- Studying the strengthening flat-plates by steel collars under impact and dynamic loads.
- Studying the behavior of strengthening flat-plates by steel collars with different ratios of flexural reinforcement under eccentric load.
- Investigating the nonlinear behavior of flat-plates strengthening by steel collars with high strength of concrete and different slab thickness under eccentric load.
After the scientific discussion by the members of the discussion committee and listening to the researcher’s defense. The evaluation of the thesis grants the researcher a doctorate in structural engineering.
