Abstract
It has become possible to produce large size threaded reinforcing bars such as having 57 mm, 64 mm and 70 mm diameters in Japan. Recommendations for Design and Construction of Large Size Threaded Reinforcing Bars D 57 and D 64 have been established by The Japan Society of Civil Engineers. In this paper, research and development works are reviewed focusing on mechanical and chemical qualities of D 57 and D 64, flexural cracking behaviors of concrete members reinforced with D 57 and D 64, performances of crack reducing bars, coupler joints, mechanical anchorages, and proposed steel truss frames. Some important comments in the Recommendations are also presented for rational utilization of large size threaded bars.
