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Insufficiency of the Beam Column Joint (BCJ) caused structures failures particularly in case of the earthquakes. In most of the buildings, the beam center line was not aligned with the column center line. So, the effect of the eccentricity of the beam was studied in this article. Behaviour of reinforced concrete (RC) eccentric beam-column joint under reversible cyclic loading was investigated experimentally. The experimental program is one specimen. The specimen consisted of column and beam. The column divided into symmetry two parts (upper and lower parts). The beam fixed in middle of the column and it was free end. The main parameter was the effect of the eccentricity of the beam center line about the column center on behaviour of RC BCJ. The specimen was tested under reversible ten cycles. The horizontal displacement for the column and the vertical deflection at free end of the beam were recorded at each cycle. The crack pattern of the tested specimen was studied at every cycle in details. It was noticed that the eccentricity of the beam has concentrated more stresses on the joint side close to the eccentricity. The failure took place at the joint due to its weakness.

The objective of this study is to use autoclaved aerated concrete (AAC) for infill walls in existing buildings that are unsafe for earthquakes to increase their stiffness. The study included two topics; the first topic introduced six models using AAC in buildings resistance to earthquakes and the effect of self-weight of the buildings comparing bare frame clay partition masonry model (1), bare frame AAC partition masonry model (2), reinforced concrete frames clay infill wall model ( 3), reinforcement concrete frames AAC infill wall model ( 4), reinforcement concrete frames AAC infill wall core model ( 5), reinforcement concrete frames AAC infill wall first and second floors model (6). ETABS software was used to investigate all frame models. Results of the study revealed that AAC infill wall decreases base moment, base shear and displacement. On the other hand, second topic presented five models of single reinforcement concrete frame under lateral loading, considering effect of anchored and unanchored AAC infill wall and clay infill wall. These models are bare frame model (a), RC frame with clay infill wall unanchored model (b), RC frame with AAC infill wall unanchored model (c), RC frame with clay infill wall with anchors model (d), RC frame with AAC infill wall with anchors model (e). Using finite element software (ANSYS WORKBENCH 18.2) failure load, displacement and ductility were presented for all five frames. The results showed that the 'RC frame with AAC infill wall with anchors' model gives the biggest failure load whereas displacement and ductility are the lowest.

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Flat slabs are widely used in construction operations because of their simplicity and ease. However, this type of structures can be subjected to brittle punching shear failure in the slabcolumn connections. Without shear reinforcement, the slab column connection can suffer brittle punching failure. In order to overcome the risk of brittle punching shear failure in the column vicinity, the use of post installed shear bolts as a transverse reinforcement is investigated in this paper. A set of six half scale reinforced concrete slab column connections were tested under monotonic concentric load. Three of the tested specimens were provided with steel shear bolts after the hardening of the concrete. Results indicated an enhanced punching strength for specimens provided with steel shear bolts. The increase in punching capacity was combined with a significant increase in both ductility and rotational capacity.