Concrete placed against an existing concrete surface: the modification of the requirements for cover to the reinforcement
Eurocode 2 part 2: Design of concrete bridge structures 18.104.22.168 (109)
The cover needs only satisfy the requirements for bonds (see EN 1992-1-1, § 22.214.171.124 (3)), provided the following conditions are met :
- the existing concrete surface has not been subject to an outdoor environment for more than 28 days
- the existing concrete surface is rough
- the strength class of the existing concrete is at least C25/30.