Shape codes are the building stones of a perfect bar bending schedule.

When calculating the reinforcement detailing for different members for a building, taking account of small bent ups and other angle detailing will make the difference of effective and economic BBS.

This is will effectively minimise the cost and wastage of reinforcement.

We have already covered how to calculate a cutting length of bent up bars? which is also useful for this explanation.

Let’s get started,

You may be noticed in beams & slabs there are number different bent ups, cuttings, and development lengths. Each and every bend and angle provided in the member is the result of design calculation. So we should precise about implementing those in practice.

However for small projects, we don’t calculate these details, we just add a few more inches and calculate the Bar Bending Schedule.

In the upcoming posts, we are going to discuss Bar Bending Schedule in more detail. So be familiar with the below shape codes.

Bar Bending Shape | Total length of bar (L) |
---|---|

L = A | |

A+(B)-0.5r-d | |

A+(B)-0.43R–1.2d | |

A+0.57B+(C)-1.6d | |

A+(B)-4d | |

A+(B) | |

A+B+(C)-r–2d | |

A+B+C+(D)-1.5r–3d | |

A+B+(C)–r–2d | |

A+B+(C) | |

A+B+(C) | |

A+B+(C) | |

A+B+(C)-0.5r-d | |

A+B+(C)-0.5r-d | |

A+B+(C)-r-2d | |

A+B+C+(D)-1.5r-3d | |

A+B+C+(D)-1.5r-3d | |

2A+ 1.7B+2(C)-4d | |

A+B+C+(D)-0.5r-d | |

A+B+C+(D)-0.5r-d | |

A+B+C+(D)-r-2d | |

A+B+C+D+(E)-2r-4d | |

A+B+C+D+(E)-2r-4d | |

A+2B+C+(D) | |

2A+B+2C+1.5r-3d | |

2(A+B+C)-2.5r-5d | |

A+B+C+(D)+2(E)-2.5r-5d | |

2A+3B+2(C)-3r-6d | |

A+2B+C+D+E+F-3r-6d | |

A | |

π (A – d)+B | |

Cπ(A-s) | |

A+2B+C+(D)-2r-4d |

### Minimum scheduling radius, former diameters, and bend allowances

Nominal size of bar, d, mm | Minimum radius for scheduling, r | Minimum diameter of bending former | General (min 5d straight), including links where bend ≥ 150° mm | Links where bend ≤ 150° (min 10d straight) mm |
---|---|---|---|---|

6 | 12 | 24 | 110* | 110* |

8 | 16 | 32 | 115* | 115* |

10 | 20 | 40 | 120* | 130 |

12 | 24 | 48 | 125* | 160 |

16 | 32 | 64 | 130 | 210 |

20 | 70 | 140 | 190 | 290 |

25 | 87 | 175 | 240 | 365 |

32 | 112 | 224 | 305 | 465 |

40 | 140 | 280 | 380 | 580 |

50 | 175 | 350 | 475 | 725 |

Happy Learning 🙂