SpEC Water-based Concrete Surface Retarder SpEC Surface Retarder is a chemical treatment for concrete formwork systems, which reacts with the surface paste to retard the hydration of cement. USES SpEC Surface Retarder is used where an exposed aggregate finish is required for architectural effects or structural considerations, e.g. mechanically sound construction joints APPLICATIONS • Precast concrete panels • Kickers • Thin and thick in-situ concrete joint sections FEATURES • Versatile – can be used over the shutter or on the exposed concrete face • Cost effective – reduction in time and labor as compared to chiseling • Does not require mould release agent • Economical – high rates of application • Compatible with a wide range of mould surfaces – SpEC Surface Retarder must be allowed to dry for 12-24 hours prior to placing concrete. – On exposed concrete surfaces, SpEC Surface Retarder is sprayed using a knapsack unit adjusted to produce a fine mist. It should be applied immediately after placing and finishing, while the concrete is still wet. – As soon as the concrete has hardened enough to be self-supporting, the mould should be stripped and the retarded concrete surface removed by wire brushing or water washing.
