# Partial safety factor for concrete: the reduction based on assessment of concrete strength in finished structure, `η` and `γ`_{C,red4}

_{C,red4}

## Eurocode 2 part 1-1: Design of concrete structures A.2.3 (1) - Annex A (informative)

For concrete strength values based on testing in a finished structure or element, cf. EN 13791 - Assessment of concrete compressive strength in structures or in structural elements, EN 206-1 and relevant product standards, the partial factor for concrete `γ _{C}` may be reduced by the conversion factor

`η`.

The value of the partial factor for concrete `γ _{C}` to which this reduction is applied may already be reduced according to § A.2.1 (1), § A.2.1 (2) or § A.2.2 (1), § A.2.2 (2). However, the resulting value of the partial factor should not be taken less than

`γ`.

_{C,red4}## Recommendation

The recommended value of `η` is 0,85, of `γ _{C,red4}` is 1,3.