An Experimental Study of Beam-Column Joints with Closely Spaced Headed Bars and Self-Consolidating Concrete

Structural engineers have restrictions on the use of headed bars to reduce the congestion of the reinforcement in the joints have limitations. Some of these limitations are related to the type of concrete used and the clear space between the headed bars. In the present research, 6 exterior joint specimens with a scale of 2/3 scale constructed and then placed under cyclic loading. These tests were conducted in order to investigate the seismic criteria of these types of joints in three ways: 1) changing the type of concrete used from the normal one to the self-consolidating one; 2) decreasing the clear spacing existing between the headed bars to 2.06db, and 3) applying two layers of headed bars that have the vertical spacing of up to 2.50db from each other. The obtained results revealed that applying the self-consolidating concrete (SCC) led to the improvement of the joints seismic behavior; also, the joint performance was still acceptable with the reduction of the clear spacing between the bars and the use of two layers of headed bars.