Process for the protection of reinforcement in reinforced concrete

A reinforced concrete wherein the content of voids in the concrete at the surface of the steel is below 0.8% preferably below 0.5% by area of the steel and wherein one or more sacrificial anodes are connected to the steel reinforcement the galvanic effect being sufficient to generate a current to cause the formation of alkali at the surface of the steel but avoid the discharge of hydrogen gas.

A process for reducing corrosion of steel reinforcement in concrete which process comprises forming a reinforced concrete in which the voids at the steel surface are below 0.8% by area of steel and in passing a direct electric current between an anode and the reinforcement as cathode to form a layer of solid alkali at the steel surface, the layer being at least 1 micron in thickness and covering at least 20% of the steel surface.

A process for reducing corrosion of steel reinforcement in reinforced concrete which process comprises, prior to casting the concrete, applying an alkali to the steel to form a layer, preferably at least one micron in thickness and covering at least 20% of the steel surface, and casting the concrete and controlling the casting conditions so that the content of voids in the concrete at the steel surface is below 0.8%, preferably below 0.5% by area of the steel surface.

A process for reducing corrosion of steel reinforcement in reinforced concrete which process comprises:

• soaking the concrete with water to cause the water to penetrate the concrete and passing a direct electric current between an anode and the steel reinforcement as cathode to form a layer of solid alkali preferably at least one micron in thickness on the steel surface.

A process for reducing the corrosion of steel in reinforced concrete which process comprises forming a layer of solid alkali preferably at least one micron in thickness on the steel by passing a direct electric current between an anode and the reinforcement as cathode before the concrete has hardened and wherein the conditions are controlled to avoid the discharge of hydrogen gas.

A process for reducing the corrosion of steel reinforcement in reinforced concrete which process comprises, prior to casting the concrete, applying a solid alkali to the steel, preferably to provide a layer of alkali at least one micron and less than 500 microns in thickness in thickness, and then casting the concrete.

A process for reducing the corrosion of steel reinforcement in reinforced concrete which process comprises prior to casting the concrete, applying to the surface of the steel an agent that will react with the pore solution of the concrete to form solid alkali on the steel, preferably in the form of a layer at least one micron in thickness and then casting the concrete.