摘要 |
The invention relates to an emulsion consisting of an oily phase dispersed in an aqueous phase, comprising a non-quaternary amine surfactant and an acid with a set-retarding effect as well as to a method for its preparation. Moreover, it relates to a method for surface retarding of a hydraulic composition, comprising the steps of: (a) shaping the hydraulic composition; (b) applying onto the surface of the hydraulic composition, the emulsion according to the invention, which by breaking releases the oily phase; and (c) after hardening of the hydraulic composition, removing the film formed with the non-hardened hydraulic composition surface layer. |