Always regarded as a difficult material to repair, concrete now seems to be on the verge of shaking off this unfortunate reputation. The picture has changed as a result of the development of a new family of adhesives- epoxy-thiokol. This adhesive, as of 1957, has been used for the restoration of spalled and cracked surfaces of concrete bridges, buildings, and highways, for cementing traffic line center markers, and for raised traffic bars to highway surfaces. When properly cured, epoxy adhesives are also effective for grouting steel bolts in concrete. In a laboratory study conducted by the California Division of Highways, a 6 by 6 by 30 inch plain concrete beam was broken in flexure and then the two pieces were cemented together with an epoxy-thiokol adhesive. After curing for seven days, the cemented beam was again loaded to failure. In every case the new breaks occurred at points other than the original fractures leading researchers to believe that the bond of the adhesive was stronger than the concrete itself.