# Design fatigue strength of concrete `f`_{cd,fat}

_{cd,fat}

## Eurocode 2 part 1-1: Design of concrete structures Expression (6.76)

The design fatigue strength of concrete, `f _{cd,fat}`, is calculated from:

f = _{cd,fat}k⋅_{1}β(_{cc}t)⋅_{0}f⋅(1 - _{cd}f/250) _{ck} | (6.76) |

where:

`f`_{ck}- is the characteristic compressive strength of concrete, see Table 3.1
`f`_{cd}- is the design compressive strength of concrete, see § 3.1.6 (1)P
`β`(_{cc}`t`)- is a coefficient which depends on the age of the concrete
`t`:`β`(_{cc}`t`) = exp {`s`[1 - (28/`t`)^{1/2}] }(3.2) with

`t`- the age of the concrete in [days]
`s`- a coefficient which depends on the type of cement:

= 0,20 for CEM 42,5 R, CEM 52,5 N and CEM 52,5 R (Class R)

= 0,25 for CEM 32,5 R and CEM 42,5 N (Class N)

= 0,38 for CEM 32,5 N (Class S).

`t`_{0}- is the time of the start of the cyclic loading on concrete
`k`_{1}- is a Nationally Determined Parameter, see § 6.8.7 (1).

This application calculates
the design fatigue strength of concrete `f _{cd,fat}`
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Intermediate results will also be given.