The need of high quality of concrete is increased in the recent years.
Using steel of high grade and maximize the benefit of using this steel
became necessary. So, different ribs are used for steel bars to increase
the bond strength between steel reinforcement and concrete. There are
different forms of rib geometry of I he deformed bars with either
Crescent or Tree profiles for all types of steel in the Egyptian market.
Anchorage of reinforcing bars of the beam-column connections is an
important design consideration for providing continuity and safety m
reinforced concrete structures. This anchorage may be provided by
development of straight bars into the exterior joints,
The Egyptian Codes of practice 208 (1995) [1] and 203 (2001) [2] give
the values of development length of the deformed reinforcement bars
regardless the geometry and the relative area of the ribs.
The main objectives of this research is to study the effect of the rib
geometry and the relative rib area on the bond characteristics, the
rotational capacity, crack pattern, the mode of failure, the deformation
capacity and bond stress of the exterior joints of the structure.
Six specimens of cantilever-to-column connections, which represent
exterior joints in structural system, were tested. Type of steel, rib
geometry, and bonded part were variables in the tested specimens.
The study concluded that the geometry of the ribs and the bonded part in
addition to the steel type have reasonable effect on the bond
characteristics of the cantilever-to-column joints and hence on the
ultimate load capacity of the joint