Composition and procedure for obtaining exposed aggregates on molded concrete surfaces and other cementitious materials

摘要

A composition for coating a mold or formwork and for demolding cast cement and concrete materials therein, comprising: A plurality of particles comprising: (a) at least one effective non-ordinary Portland cement binder (not OPC) to form a coating when mixed with at least one inert load and water to form a uniform mixture, said non-ordinary Portland cement binder (not OPC) being present in the amount of at least 1 percent; (b) at least one effective inert charge with said at least one non-ordinary Portland cement binder (not OPC) to form a coating when mixed with water and to harden in the mold or formwork, said at least an inert filler being present in the amount of 5 to 80 percent and comprising calcium carbonate, silicon dioxide, barium sulfate, talc, mica or mixtures thereof; (c) optionally at least one effective accelerating agent for accelerating the setting of said at least one non-ordinary Portland cement binder (not OPC), said at least one optional non-ordinary Portland cement binder accelerator (no OPC) being present in the amount of 0 to 5.0 percent; and (d) at least one ordinary Portland cement (OPC) setting retarder effective to retard the setting of ordinary Portland cement (OPC) or concrete inside the mold or formwork, said at least one retarding agent of the setting of ordinary Portland cement (OPC) being present in the amount of 0.5 to 40.0 percent; the above percentages being based on the total dry weight of the coating composition.