Estimating Sheet

# Bar Bending Schedule Calculation

Construction Software

Bar bending schedule refers to a vital structural working document that is used for obtaining the disposition, bending shape, and total length of all the reinforcements included in the structural drawing along with the quantity.

It belongs to the bar mark from structural detailing drawing that is transmitted to the bar bending schedule. The unit mass of the reinforcements is obtained from the density of steel. The density of steel should be 7850 kg/m3 for this purpose.

Details about 12mm bar: The area of steel of steel is determined as follow -

πd2/4 = π×122/4 = 113.097mm2 = 0.0001131m2

Based on the unit length of the bar, the volume is verified as 0.0001131m3

Knowing full well that Density = Mass/Volume

7850 = Mass/0.0001131

So, the unit mass of 12mm Bar = 7850 × 0.0001131 = 0.888 kg/m

Weight per metre = 0.006165×(dia. Of bar)2 {kg}

8mm = 0.395kg/m
10mm = 0.616kg/m
12mm = 0.888kg/m
16mm = 1.579kg/m
20mm = 2.466kg/m
25mm = 3.856kg/m

32mm = 6.313kg/m
40mm = 9.864kg/m

Some basic standard shapes contain definite shape codes. But in modern bending schedule, shape codes are rarely found. However, the genuine shape of the member is drawn out for the fitters (iron benders) to follow.

To determine the length of reinforcement bars, the following relation should be used :-

Length of bar = Effective Length + Width of Support – Concrete cover (s) – Tolerances (say 10mm)

Reinforced concrete is a structural material that is extensively used in engineering construction. Though concrete is strong in resisting compressive stress, it is weak in tension. In order to resist tensional stresses, steel should be provided in concrete.

The reinforcement in concrete ranges from simple bars or rods bend which are attached to a given schedule with stirrups. The least diameters of bars in the construction site should be Y10, Y12, Y16, Y20, Y25 and Y32 and Y40.

Steel are available in two basic types:

Mild steel (250 N/mm2)
HYSD steel (460 N/mm2)

Article Source: engineeringbasic.com