For full functionality of this site it is necessary to enable JavaScript. Here are the instructions how to enable JavaScript in your web browser.

Initial prestress force applied to the concrete: the values of k7 and k8

Eurocode 2 part 1-1: Design of concrete structures   5.10.3 (2)

The value of the initial prestress force Pm0(x) (at time t = t0) applied to the concrete immediately after tensioning and anchoring (post-tensioning) or after transfer of prestressing (pre-tensioning) is obtained by subtracting from the force at tensioning Pmax the immediate losses ΔPi(x) and should not exceed the following value:

Pm0(x) = Apσpm0(x) (5.43)


is the stress in the tendon immediately after tensioning or transfer, = min {k7fpk; k8fp0,1k}.


In this calculation of the initial prestress force applied to the concrete, the recommended value for k7 is 0,75 and for k8 is 0,85.

National choice