Comprehension of demoulding mechanisms at the formwork/oil/concrete interface

The implementation of concrete and its association with a release agent influence the aesthetics of the concrete facings. The mineral oils tend to be replaced by vegetable formulations, to reduce the impact of the substances spilled in the environment. From a technical point of view, it is important to characterize the action of these new formulations at the interface concrete/oil/formwork. Two performing techniques have been used to study the physico-chemical processes, the tribometry and electrochemical impedance spectroscopy. The correlation of the results obtained allowed to improve the understanding of the mechanisms involved at the interface mould/oil, in connection with the use of an acidifier in the formulation.