There are many challenges unique to repairing historic concrete, not the least of which is matching the color, finish, and texture of the existing concrete as closely as possible.
Repair of historic concrete should begin with an investigation of the concrete to evaluate the existing condition and determine the causes of distress and deterioration. Then, before beginning full-scale repair work, the contractor should carry out two additional steps: develop a repair concrete mix that will meet both performance and appearance requirements, and construct mock-ups to demonstrate that the materials and methods proposed will produce an acceptable repair.