To participate in repair and rehabilitation successfully, the contractor must pay close attention to four basic steps in the repair process--evaluation of causes, extent, and consequences of deterioration; selection of repair material; preparation for repair; and placing of repair material. Before any repair is attempted, the contractor should find out what caused the deterioration, how extensive it is, and whether repair is feasible. Frequently this evaluation is done by a consultant having the specialized equipment to supplement visual observations with tests. The contractor who conducts an evaluation himself must also know what not to repair. Demolition and reconstruction may be best when weather, repair time, appearance, or disagreement over liability and payment make repair an unsatisfactory solution.
Many different repair materials are available. On large projects, if there is any doubt about the compatibility of a repair material with the adjacent concrete, a test installation is recommended. Use the material under placement and exposure conditions identical with the job to be done. Observe the results for periods of up to a year. The major disadvantage is the delay; however, early detection of incompatibility problems can pay big dividends.
Performing the repair may involve several of the following--crack repair, replacing deteriorated concrete, realigning displaced elements, and augmenting or strengthening existing members. Since each repair job may involve unique conditions, the contractor must frequently tailor the methods and materials used. No single procedure can be routinely followed, and careful planning is needed from evaluation through execution.