Forming patterns of exposed aggregate on concrete surfaces - by selective coating of a concrete moulding with a retardant

摘要

Patterns are made on the surface of concrete, by exposing the aggregate in specific zones (a) before final setting of the concrete. A mould element is coated in specific zones (b), corresp. with zones (a), with a retardant, and the mould element is used on the base or top surface of the mould. - The mould element is pref. re-used after recoating with the retardant, which is pref. applied via a roller or via a template providing the desired pattern. Any known retardant may be used, e.g. sugar soln. contg. dextrin, MgCl2 lye contg. beet juice, petrol or tannic acid contg. starch. The mould element is pref. a strong material e.g. paper, coated on one side with a pattern of retardant, esp. in spongy or absorbent zones (b). - Sharply defined patterns can easily be obtd. on a concrete surface.