The inherent brittleness of a cement matrix can be substantially overcome by dispersing therein a suitable amount of a suitable fibrous material, such as carbon fiber.  Since the development of inexpensive pitch-based carbon fibers, extensive studies on a practical use of carbon fiber reinforced concrete have been made, and great expectations are entertained of this new construction material having strngth, distortion and elastic properties which have not been realized by the heretofore available cement concretes. 
We have been engaged for a long year in a research and development work on the carbon fiber reinforced concrete.  During our work we have encountered a problem which is not the case with ordinary concrete.  The problem is a phenomenon that if metal is in contact with carbon fiber reinforced concrete, corrosion (oxidation) of the metal extensively proceeds during the curing of the concrete.  More specifically, when carbon fiber reinforced concrete is cured while being in contact with ferrous metallic members, such as reinforcing steel bars and meshes, steel molds, bond wires, anchor fasteners, spacers and the like, corrosion of the metal rapidly proceeds during the curing of the concrete on those areas of the ferrous metallic members where they are in contact with the concrete to an extent unexpected with ordinary concrete.