bbs of rectangular beam with curtail bar

BBS of rectangular beam provides comprehensive details about the reinforcing bars (rebar) required for constructing a rectangular beam with a curtail bar. This document serves as a crucial reference for contractors and laborers during the construction process.

Steps to calculate bbs of rectangular beam with curtail bar

Step 1: Beam Information

Include beam dimensions such as length, width, and depth.

Specify material specifications and any special requirements.

Step 2: Bending and Cutting Details

Specify bending shapes and dimensions for each type of rebar, including the curtail bar.

Detail hook lengths, bend angles, and distances between bends.

Step 3: Rebar Type and Diameter

Provide a comprehensive list of rebar types and their corresponding diameters.

Include details for both main reinforcement and the curtail bars.

Step 4: Spacing and Splicing Details

Define the spacing between bars and indicate any required lap splices for connecting bars together.

Provide clear instructions on the locations and methods for splicing.

Step 5: Bar Marking and Identification

Assign distinct identification numbers or codes to each type of rebar.

Facilitate accurate placement during construction.

Step 6: Quantity Calculation

Determine the total quantity of each type of rebar needed based on the beam’s dimensions, structural requirements, and design specifications.

Step 7: Placement Details

Provide Clear Placement Instructions:

Offer precise instructions on how each type of rebar should be positioned within the beam.

Include information on cover requirements, specifying the distance from the surface to the nearest rebar, and any special considerations.

Step 8: Curtail Bar Details

Specifically detail the curtail bar, covering its length, diameter, placement location, and anchorage requirements.

Step 9: Bar Schedule Diagram

Create a graphical representation of the bar bending schedule to visually illustrate the arrangement and placement of the rebar within the beam.

Step 10: Material Specifications

Provide information about the type and grade of concrete and steel to be used.

Include any special instructions regarding their quality and testing.

Step 11: Additional Notes and Considerations

Provide any additional information or specific considerations that may be relevant to the construction of the beam.

bbs of rectangular beam having curtail bar

beam section


length = 3000mm

depth = 300mm

width = 350mm

clear cover = 30mm

main bar = 16mm

extra bar = 12mm

spacing of stirrups = 300mm C/C

Ld(development length) = 50d, d=diameter of bar





Calculation of top & bottom main bar

bbs of rectangular beam top & bottom main bar

Top main bar

Cutting Length = beam length+(2*Ld)-(2*bends)

=3000+(2*50*16)-(2*2*16) = 4536mm

weight = ((d^2/162)*CL)/1000= ((16^2/162)*4536)/1000= 7.168Kg

Bottom main bar

cutting length = Length of beam+(2*Ld)-(2*bends)

=3000+(2*50*16)-(2*2*16) = 4536mm

weight = ((d^2/162)*CL)/1000= ((16^2/162)*4536)/1000= 7.168Kg

Calculation of top & bottom extra bar

Top extra bar

Cutting Length = (beam length/3)+(2*Ld)-(2*bends)

=(3000/3)+(2*50*12)-(2*2*12) = 2536mm

weight = ((d^2/162)*CL)/1000= ((12^2/162)*2536)/1000= 2.254Kg

Bottom extra bar

cutting length = beam length – (2*(beam length/8))

=3000-(2*(3000/8)) = 2250mm

weight = ((d^2/162)*CL)/1000= ((12^2/162)*2250)/1000= 2Kg

Calculation of stirrups


No. of stirrups =((beam length -(2*cc))/spacing)+1

=((3000-(2*30))/300)+1 = 10.8 ~ 11nos.

cutting length = ((2*beam depth)-(2*clear cover))+((2*beam width)-(2*clear cover))+(2*hook length)-(2*135°bend)-(3*90°bend)

= ((2*350)-(2*30))+((2*300)-(2*30))+(2*10*10)-(2*3*10)-(3*2*10) = 1260mm

weight = ((d^2/162)*CL)/1000= ((10^2/162)*1260)/1000= 0.78Kg

bbs of rectangular beam report

Sl. No.DestriptionBar dia (mm)spacing (mm)CL (mm)No. of barsWeight (Kg)
1Top main164536214.34
2Bottom main Bar164536214.34
3Top extra bar12253649
4Bottom extra bar12225024

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