T-Headed Stirrup Bars

The T-headed stirrup bars are an efficient and structurally reliable method of providing transverse reinforcement to resist shears and to provide confinement of the concrete core. This paper describes the development of the concept and its testing. Initial testing is described, as well as the beam test and other field tests and field application. Its manufacture and on-going developments are also discussed. Research now commencing in Norway will seek to optimize the T-headed bars and quantify their limitations and allowable tolerances in placement. The best method of manufacture appears to be controlled friction welding. These bars are efficient, and result in higher strengths and ductilities in flexural/punching shear members, and provide greater space for the placement and vibration of concrete, thus assuring that the resultant composite structural element will of optimal quality.