How to Prepare Bar Bending Schedule (BBS) in Excel

 What is Bar Bending Schedule?

Bar Bending Schedule (BBS) is detail quantification of re-bar used in construction. BBS is prepared prior to the construction in-order to find out actual requirement of rebar in the project. The site engineer prepares the BBS and is to be approved by Project Manager. BBS helps procurement manager to identify which and how much rebar are required in a time. In overall, bar bending schedule is a key task of project management.

What a Bar Bending Schedule includes?

• Diameter of Rebar
• Length of Rebar
• Number of Rebar
• Specification code of Rebar
• Weight of Rebar
• Shape of rebar to be belt
• Location of use
  

 

 Bar Bending Schedule Format

Item Code	Description							Length (m)	Nos	Total Length (m)	Dia (mm)	Unit Wt (kg/m)	Total wt (kg)	Remarks
s1
				7.95				7.95	18	143.1	10	0.61	87.29	Seat Bar
s2 @ 200 c/c					0.12
				0.31		0.32		1.35	80	108	10	0.61	65.88	Beam
					0.05
				0.55
s3 @ 250 c/c
					0.6			0.6	132	79.2	16	1.58	125.13	Dowel Bar
a1 @ 120 c/c
		0.1				0.1		3	45	135	12	0.88	118.8	Distribution Bar
				2.8
a1 @ 120 c/c (every third bar cranked)		0.7			0.7
	0.1		0.28		0.28		0.1	3.16	22	69.52	12	0.88	61.17	Distribution Bar (cranked)
				1
a2 @ 150 c/c
		0.1				0.1		8.15	20	163	10	0.61	99.43	Transverse Bar
				7.95
a3 @ 300 c/c
		0.1		2.8		0.1		3	28	84	10	0.61	51.24	Top Distribution
a4 @ 300 c/c
		0.1		7.95		0.1		8.15	10	81.5	10	0.61	49.71	Top Transverse
a5 - 1 each longer side				7.95
		0.1				0.1		8.15	2	16.3	12	0.88	14.34	Extra Bar
												Total wt:	672.99	Kg

 Click Here to Download BBS format in Excel

Lapping of Rebar

 Generally, length of a rebar is 12 m. But during construction a structure i.e beam or slab or column could have length longer than the length of rebar. In such case, two or more rebar are lapped. Here is a guidelines that must be followed while lapping of rebar.

• Lapping Length - Lapping length of rebar is calculated by formula 60D or 65D. For minor structures such as building, culverts, etc lapping length is 60 times the diameter of rebar lapped. Example: 12 mm rebar is lapped 720 mm (60x12). In case of sky scrapers, bridges, flyover lapping length is 65D.
  
• Location of Lapping - Lapping location must be avoided where bending moment is maximum. In beam, bending moment is maximum in center of length, thus bottom bar must not be lapped at center.
  
• Inter-lapping distance - There is not hard and fast method how far a bar can be re-lapped but it is recommended not to lap rebar within 6 meter from a lap.