Pullout Tests on Concrete Breakout Strength of Headed Reinforcement Bars Embedded in Roof Exterior Beam-Column Joints

Recently, the use of headed bars as mechanical anchorage in reinforced concrete beam-column joints has increased rapidly. This type is used for T-shaped beam and exterior column at middle floors L- rooftops buildings. However, few experimental data are available regarding capacity embedded L-shaped joints. Nine pullout tests conducted to investigate Parameters affecting capacity, such diameter, embedment length, location bars, number supplementary considered. The evaluated using empirical formulas proposed by Kubota Murakami a formula cone failure. failure behavior specimens with cracks propagating diagonal direction maximum applied load. increases length diameter area. For most specimens, overestimate whereas yields lower capacities compared test results.