Development of Rib Plate Manufacturing Technique

The use of concrete-filled, ribbed steel tubular columns has been increasing gradually in construction work. These columns offer high strength and stiffness, in addition to advantages in construction work, such as the elimination of formwork. The demand for integral rib plates in these concrete-filled, tubular columns will increase as more high-rise buildings are built in the future. This report presents a technique for manufacturing rib plate using multi-pass rolling. This technique was established by rolling rib plates on a trial basis using a plate mill at NKK's Fukuyama Works, after experiments on rib formation using lead and hot-rolled carbon steel. To assure the required rib shape and to prevent lap defects and distortion from rolling, the rolling pass schedule was established by combining the optimum rolling reduction in each pass with shape control using work roll shift and work roll bender technology. This technique enabled the efficient production of well formed rib plates by the multi-pass rolling method.