Minimum cover due to bond requirement of prestressing tendons cmin,b
Eurocode 2 part 1-1: Design of concrete structures 188.8.131.52 (3)
In order to transmit bond forces safetly and to ensure adequate compaction of the concrete, the minimum cover should not be less than cmin,b.
The minimum cover with regard to bond for reinforcement steel is given in Table 4.2.
The following recommendation applies to the prestressing tendons.
The recommended values of cmin,b for post-tensioned ducts are:
- circular ducts: diameter
- rectangular ducts: greater of the smaller dimension or half the greater dimension
There is no requirement for more than 80 mm for either circular or rectangular ducts.
The recommended values of cmin,b for pre-tensioned tendon are:
- 1,5 x diameter of strand or plain wire
- 2,5 x diameter of indented wire.