Steel reinforcing rod with two opposed longitudinal ribs - has pairs of slanting ribs at spacings related to nominal rod dia.

摘要

A steel rod for use in reinforcing concrete has two ribs parallel to its longitudinal axis and diametrically opposed. Between the longitudinal ribs are crescent- shaped parallel ribs an angle of between 40 deg. and 70 deg. with the longitudinal rod axis. The slanting ribs are grouped in pairs at regular intervals, the distance between the adjacent ribs belonging to two different pairs being between 1.5 and 3.5 times the distance between two ribs of the same pair. The total distance between two ribs belonging to the same pair and two adjacent ribs belonging to different pairs and divided by the sine of the angle made by the planes of the slanting ribs with the longitudinal axis of the bar is equal to maximum of 1.6 times the nominal rod diameter.