| 摘要 |
Steel rods are formed, by hot rolling, with at least three (preferably four) series of ribs extending along the length thereof. The ribs are all formed to extend along a spiral line along the surface of the rods and are so constructed that any cross-cut through the rod must pass through at least one rib. Each of the ribs has end portions which gradually blend into the core of the rod, which core is substantially circular in cross-section. The outer surfaces of the end portions are substantially straight and tangential to the core. Thus, when viewed from the end or in cross-section, the rod has the appearance of a polygon. The polygonal shape of the rod prevents it from rotating after embedding it in concrete when tension is applied to an end thereof. The spiral arrangement permits tension to be applied to the rods by means of screw nuts, etc. |
