Steel spiral reinforcing member for concrete - comprises high grade steel spirally wound without plastic deformation when stretched

摘要

The steel spiral reinforcing member for use in concrete construction can be applied as a support stirrup loop or as a ring reinforcement unit. High grade steel is wound in a helical configuration, without sustaining any plastic deformation when it is stretched out from the fully pressure-loaded condition. The steel has a yield strength over 55 kg/mm22. A rounded-off head may be formed at the end of the member. The original material can be worked into a spiral shape with helically aligned recesses on the periphery, by heating to the normal temp; or it can be cold worked and then heated to 200 deg. to 400 deg.C. This can be stretched smoothly and without friction, to form part of an entity adhering durably to the concrete.