Adhesion of the corresponding coating, how many indicators can be met to meet the requirements?

In ISO12944-6, the adhesion requirement for the coating system (when the dry film thickness is greater than 250µm) is to follow the ISO4624 pull-off adhesion test method, at least 5MPa.

"Technical Specifications for Anti-corrosion of Concrete Structures in Seaport Engineering" JTJ275-2000 stipulates that the adhesion between the anti-corrosion coating of new structures and the concrete surface should not be less than 1.5 MPa, and if the coating system has reached the design service life, the adhesion is still not less than 1 . 2MPa, and there are no cracks, air bubbles and severe pulverization on the surface, it can be considered to continue to be used.

For the maintenance of the old coating, the reference value must reach at least 2MPa, then it can be considered that the original coating has a certain adhesion and can be retained, otherwise the old coating will be removed.