Prolonging the lifetime of existing reinforced concrete infrastructures with thermal sprayed zinc coating anodes

Metallic zinc coatings protect steel from corrosion by acting first as a barrier coating and more importantly as a sacrificial anode. Zinc will provide galvanic protection to the steel. As such, concrete structures reinforced with plain or black steel showing signs of distress can be galvanically protected with external zinc anodes. Thermal sprayed metallic zinc coatings on the exposed surface of the concrete can be electrically connected to the steel reinforcement and provide corrosion protection to the steel.Thermal sprayed zinc coatings were successfully tested as anodes in cathodic protection systems for reinforced concrete structures in the United States. Subsequent installations were made on numerous structures, including three historic reinforced concrete bridges in the state of Oregon. The 20-plus-year performance confirms that the service life of reinforced concrete structures can be significantly and economically extended by using metallic zinc anodes to protect the plain steel reinforcement from further corrosion.