Formation Of Bar Bending Schedule
A list of reinforcement bars is called bar bending schedule (or schedule of bars), a given RCC work thing, and is displayed in a form of tabular layout for simple graphical reference. The following table epitomizes all the required details of bars such as diameter, shape of bending, length of each bent and straight portions, angles of bending, total length of each bar, and number of each sort of bar. During the preparation of an estimate of quantities this information will help unconditionally.
The figure below portrays the shape and proportions of hooks and bends in the reinforcement bars – these are customary proportions that are attached to:
(a) Length of one hook = (4d ) + [(4d+ d )] – where, (4d+ d ) relates to the curved portion = 9d.
(b) The supplementary length (la) that is introduced in the plain, straight end-to-end length of a reinforcement bar owing to being bent up at θ° say 30° to 60°, but it is usually 45°) = l1 – l2 = la
We get different values in respect to the θ° = 30° 45° 60° as follows :
The following figure demonstrates the method to determine the length of hooks and the total length of a given steel reinforcement.