Anchorage of longitudinal reinforcement: the ultimate bond stress fbd
Eurocode 2 part 1-1: Design of concrete structures 8.4.2 (2)
The design value of the ultimate bond stress for ribbed bars may be calculated as:
| fbd = 2,25 η1 η2 fctd | (8.2) |
where:
- fctd
- is the design value of concrete tensile strength
fctd = αct fctk,0,05 / γC (3.16) with
- fctk,0,05
- the characteristic (5% fractile) axial tensile strength of concrete, see Table 3.1
- γC
- the partial safety factor for concrete, see § 2.4.2.4 (1), § 2.4.2.4 (2), and § 2.4.2.4 (3)
- αct
- a Nationally Determined Parameter, see § 3.1.6 (2)P.
- η1
- is related to the quality of the bond condition and the position of the bar during concreting (cf. Figure 8.2):
η1 = 1,0 for "good" conditions,
η1 = 0,7 for other cases. - η2
- is related to the bar diameter:
η2 = 1,0 for Φ ≤ 32 mm,
η2 = (132 - Φ)/100 for Φ > 32 mm.
This application calculates the ultimate bond stress fbd from your inputs. Intermediate results will also be given.
