Abstract: A method of coating a reinforcing material, such as a metal, increases the adhesion between the material and a matrix, such as a cement-based mortar or concrete, in which the material is embedded. In one embodiment, a glass frit mixed with a refractory material, such as dry portland cement, is bonded, typically by heat, to the surface of the material. The reaction of the refractory component when the metal is embedded in fresh mortar or concrete prevents the formation of soft precipitates at the interface of the matrix and its reinforcement. One embodiment involves mixing portland cement Type I-II with a glass frit as a coating, coating a steel reinforcing rod and firing the coating to bond to the metal. The frit-refractory coating produces a strong bond between the metal reinforcement and its concrete or mortar matrix and may eliminate or significantly reduce the potential for corrosion of the reinforcement.