A series of vitreous enamel coatings that contain hydraulically reactive calcium
silicates have been developed to improve the performance and service life of steel used as
reinforcement in concrete structures. The new series of enamel coatings combine a layer
of alkaline-resistant basecoat glass enamel with an outer coating of glass enamel that
incorporates dicalcium silicate and tricalcium silicate. The basecoat protects the steel
while the calcium silicates in the outer layer hydrate when placed in fresh concrete and
bond tightly to the surrounding concrete paste. The bond strength between the concrete
and steel is increased two to three times that developed with uncoated steel. The enamel
over the steel produces durable corrosion protection. The new coating can be of value in
increasing the performance and the service life of defense-critical infrastructure.