الفهرس 
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Abstract
Beam-column joints are more liable to damage compared to other structural elements, when the structure is subjected to earthquakes excitations or cyclic loading.
Joints in typical buildings, constructed before issuing the current Egyptian Code of Practice ECP 95, ECCS203-2001, and ECP203-2006 (which include new regulations for lateral loads induced by earthquakes in design and detailing for both strength and ductility of different structural elements) suffer from lack adequate steel reinforcement detailing to resist dynamic excitations. In these joints, the confining reinforcement such as column stirrups does not extend in the joint region.
The pattern of joint damage in building subjected to the October earthquake in 1992 showed that the lack of joint confinement was one of the major reasons for joint damage. Hence, there is a need for an adequate economical and environment friendly method for joint confinement in strengthening or repair to safeguard against probable future earthquakes.
Several methods are available for joint strengthening, however, the use of steel wire mesh (or Ferrocement overlays) is a promising approach as all the used materials are locally produced and no material has harmful effect on human health.
The challenge in the tested models in the current study is the repair of 3D-joints with the existence of a secondary beam perpendicular to the plan of loading. This secondary beam represents an obstacle for easy wrapping of steel-wire mesh and that resembles the joint in real structures. This study test 3D beam-column joints under displacement-controlled cyclic loading.
Twenty-two full-scale specimens with various study parameters were tested. The models tested were for corner and edge joints. Test measurements include applied displacements, applied loading and induced deflection. Test comparisons were based on energy dissipation, stiffness, and strength degradation with displacements up to joint collapse initiation.
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The test results showed that strengthening with ferrocement would enhance greatly the load carrying capacity as well as the energy absorbing capacity of the joint. The ferrocement layers would substitute as shear reinforcement in the joint region. Hence, the use of ferrocement layers in strengthening joints without shear reinforcement would enhance the behavior of these joints and would reduce the vulnerability of these joints to be excessively damaged when subjected to seismic loading. Special care should be devoted to assure contact between the ferrocement layers and the concrete surface, and to avoid early separation. This can be achieved by roughness of the surface, adding dowels and steel angels.
In the analytical study, a numerical model was performed for the beam-column joint (using a finite element computer program-ANSYS). This model was verified through the experimental results, and was used to study the effect of additional variables (not considered in experimental study) on the beam-column joint behaviour.