BONDING ENAMEL COATINGS FOR STAY-IN-PLACE STEEL FORMS

摘要

Steel stay-in place forms has been proposed for use in projects as diverse as concrete bridge decks and containment domes for nuclear reactors. In all cases, the widespread acceptance of this construction technique has been halted by the problems of corrosion of the exposed steel and the lack of any durable bonding between the steel shell and the in-filling concrete. Curing of the concrete infill is accompanied by shrinkage and the weak bond at the concrete-steel interface produces an opening that exposes the inside surface of the steel shell. The corrosion typically cannot be observed or monitored until the evidence of oxidation appears as holes and blisters on the outside of the form. A novel vitreous enamel that contains reactive calcium silicate has been developed to coat steel forms and solve the corrosion problem by providing a strong, chemically-resistant surface that tightly bonds to the concrete infilling. This technology promises to provide the first practical design for durable metal forms that can become part of the reinforcement system for concrete construction. Similar coatings can be applied to standard steel rebar and to steel fiber.