# Concrete Reinforcement Shape Codes

#### General

The following bar bending rules, shape codes and bar dimensions are in accordance with BS 8666:2000.

###### Transportation

To facilitate transportation of bent reinforcement, each bent bar must fit within a rectangular area, with the shortest length of the rectangle not larger than 2.75m. Typically the total length of the bar should not be greater than 12m. It is also worth paying attention to the total weight of a bent bar and giving due consideration to mimising risk to operatives from manual handling.

###### Dimensioning, Cutting and Bending Tolerances

The dimensions of each bar bend shall be rounded to the nearest 5mm multiple, the total calculated length of of the bar is then rounded up to a multiple of 25mm.

The allowable tolerances on cutting and bending legnths are given in the table below.

Cutting and bending processes | Allowable Deviation (mm) |
---|---|

Cutting of straigh lengths, including reinforcement for subsequent bending. | ±25 |

Bending, ≤ 1000mm | ±5 |

Bending, >1000mm to ≤ 2000mm | +5, -10 |

Bending > 2000mm | +5, -25 |

>Length of bars in fabric | max(±25, 0.5% of the length) |

###### Distance Between Concrete Faces

Where a reinforcing bar is bounded on each side by a concrete face then it is important to ensure dimensioning and cutting tolerances don't reduce the concrete cover to be within the nominal cover. The following deductions should be made from the specified bar dimensions, in this instances the dimensions should be rounded down to the nearest 5mm.

Distance between concrete faces (mm) | Deduction(mm) |
---|---|

≤200 | 5 |

≤400 | 10 |

≤1000 | 15 |

≤2000 | 20 |

>2000 | 30 |

Straights between concrete faces | Deduct an additional 10mm |

###### Couplers and Heads

Where special end preparations are needed for either couplers or headed bars then the bar mark will be prefixed with an "E". I.e. E87 denotes bar mark 87 requires a special end preparation. The details of the end preparation are then annotated onto the schedule.

#### Shape Codes and Dimension Limits

The table below details the shape codes available within BS 8666:2000, along with the calculated bar length and detailing limits

Shape Code | Shape | Total length of bar, L (equation) | Detailing limits | |
---|---|---|---|---|

00 | A | |||

01 | A | Stock lengths | ||

11 | A + (B) - 0.5r - d | Neither A nor B less than P in the table below. | ||

12 | A + (B) - 0.43R - 1.2d | Neither A nor B shall be less than (R+d) + greater of 5d or 90mm. Max mandrel size is 400mm, therefore radius must be equal to or less than 200mm. | ||

13 | A + 0.57B + (C) - 1.6d | Neither A nor C shall be less than B/2 + greater of 5d or 90mm. B shall not be less than q in the table below. Max mandrel size is 400mm, therefore (B - 2d) must be equal to or less than 400mm. | ||

14 | A + (C) | Neither A nor (C) less than P in table below. | ||

15 | A + (C) | Neither A nor (C) less than P in table below. | ||

21 | A + B + (C) - r - 2d | Neither A nor (C) less than P in table below. | ||

22 | A + B + 0.57C + (D) - 0.5r - 2.6d | Neither A nor (D) less than P in table below. C not less than q in the table below. (D) not less than C/2 + greater or 5d or 90mm. Max mandrel size is 400mm, therefore (C - 2d) must be equal to or less than 400mm. | ||

23 | A + B + (C) - r - 2d | Neither A nor (C) less than P in table below. | ||

24 | A + B + (C) | Neither A nor (C) less than P in table below. A and (C) are at right angles to one another | ||

25 | A + B + (E) | Neither A nor B less than P in table below. If E is the critical dimension schedule bar as shape code 99 instead and specify A or B as the free dimension. | ||

26 | A + B + (C) | Neither A nor (C) less than P in table below. | ||

27 | A + B + (C) - 0.5r - d | Neither A nor (C) less than P in table below. | ||

28 | A + B + (C) - 0.5r - d | Neither A nor (C) less than P in table below. | ||

29 | A + B + (C) | Neither A nor (C) less than P in table below. | ||

31 | A + B + C + (D) - 1.5r - 3d | Neither A nor (D) less than P in table below. | ||

32 | A + B + C + (D) - 1.5r - 3d | Neither A nor (D) less than P in table below. | ||

33 | 2A + 1.7B + 2(C) - 4d | A not less than B/2+(C), where (C) is at least B/2 plus greater of 5d or 90mm B not less than q in the table below (C) not less than B/2 + greater of 5d or 90mm Max mandrel size is 400mm, therefore (B - 2d) must be equal to or less than 400mm. | ||

34 | A + B + C + (E) - 0.5r - d | Neither A nor (E) less than P in table below. | ||

35 | A + B + C + (E) - 0.5r - d | Neither A nor (E) less than P in table below. | ||

36 | A + B + C + (D) - r - 2d | Neither A nor (D) less than P in table below. | ||

41 | A + B + C + D+ (E) - 2r - 4d | Neither A nor (E) less than P in table below. | ||

41 Flag | A + B + C + D+ (E) - 2r - 4d | Neither A nor (E) less than P in table below. | ||

44 | A + B + C + D+ (E) - 2r - 4d | Neither A nor (E) less than P in table below. | ||

46 | A + 2B + C + (E) | Neither A nor (E) less than P in table below. | ||

47 | 2A + B + 2(C) + 2q -3r - 6d | (C) and (D) shall be both be equal. (C) and (D) shall be less than A. Neither (C) nor (D) shall be less than P in the table below. Hooks to be standard hooks as defined as q in the table below Max mandrel size is 400mm. | ||

48 | 2A + B + 2(C) -r - 2d | (C) and (D) shall be both be equal. (C) and (D) shall be less than A. Neither (C) nor (D) shall be less than P in the table below. Link ears to be bent at a minimum of 135° | ||

51 | 2(A + B +(C)) - 2.5r - 5d | (C) and (D) shall be both be equal. (C) and (D) shall be less than A or B. Neither (C) nor (D) shall be less than P for links in table below. Where (C) and (D) are to be minimised the following length equation can be used: L = 2A + 2B + max(16d, 160) | ||

52 | 2(A + B +(C)) - 1.5r - 3d | (C) and (D) shall be both be equal. (C) and (D) shall be less than A. Neither (C) nor (D) shall be less than P in the table below Link ears to be bent at a minimum of 135° so that they are parallel. Where (C) and (D) are to be minimised the following length equation can be used for bar sizes ≤ 16: L = 2A + 2B + max(20d, 180) and for bar sizes ≥ 20: L = 2A + 2B + 21d | ||

56 | A + B + C + (D) + 2(E) - 1.5r - 3d | (E) and (F) shall be both be equal. (E) and (F) shall be less than A or B. Neither (E) nor (F) shall be less than P in table below. | ||

63 | 2A + 3B + 2(C) - 3r - 6d | (C) and (D) shall be both be equal. (C) and (D) shall be less than A. Neither (C) nor (D) shall be less than P for links in table below. Where (C) and (D) are to be minimised the following length equation can be used: L = 2A + 3B + max(14d, 150) for bars ≤16mm or L = 2A + 3B + 13d for bars ≥20mm | ||

64 | A + B + C + 2D + E + (F) - 3r - 6d | Neither A nor (F) less than P in table below. | ||

67 | A | |||

75 | π (A - d) + B + 25 | Where B is the lap | ||

77 | C π (A - d) | Where C is the number of turns. Where B is greater than A/5 the length equation is: L = C ((π (A - d))²+B²)^{0.5} | ||

98 | A + 2B + C + (D) - 2r - 4d | Isometric sketch. Neither C nor (D) less than P in table below. | ||

99 | To be calculated |

#### Minimum Bend Radius, Mandrel Size and End Projections

The table below details the minimum bend radius, the minimum end projection and the anticipated hook diameter for different bar sizes. All dimensions have been rounded to the nearest 5mm. It should be noted that the anticipated hook diameter is equal to 3d + 2r, the additional "d" is to allow for spring back after bending.

Bar Size, d (mm) | Min. Radius (mm) | Min. end projection, P (mm) | Anticipated Hook Diameter (mm) | ||
---|---|---|---|---|---|

Generally (not links) | Links with bend > 150° (min. 5d straight) | Links with bend < 150° (min. 10d straight) | |||

6 | 12 | 110 | 110 | 110 | 45 |

8 | 16 | 115 | 115 | 115 | 60 |

10 | 20 | 120 | 120 | 130 | 70 |

12 | 24 | 125 | 125 | 155 | 85 |

16 | 32 | 140 | 140 | 210 | 115 |

20 | 70 | 190 | 190 | 290 | 200 |

25 | 87 | 235 | 235 | 365 | 250 |

32 | 112 | 305 | 305 | 465 | 320 |

40 | 140 | 380 | 380 | 580 | 400 |

50 | 175 | 475 | 475 | 725 | N/A |

#### Minimum Distance Between Two Bends

For all shapes with two or more bends, regardless of whether they are in same plane, a suitable gap needs to be left between bends to allow for bending. The minimum gap applies regardless of the direction of bending or the angle of the bend. The minimum values between bends for different bar sizes is given in the table below:

Norminal bar size, d (mm) | Min. value between 2 bends, X (mm) |
---|---|

6 | 75 |

8 | 80 |

10 | 100 |

12 | 120 |

16 | 160 |

20 | 260 |

25 | 325 |

32 | 416 |

40 | 520 |

50 | 650 |