Concrete repairs have occurred on Reclamation projects since the first concrete was placed in 1903. Unfortunately, even though the best available knowledge and materials were used, many repair failures have occurred during the 112 years since that first concrete was placed. As a first step to increase the likelihood of a successful repair, it is paramount to use a consistent, systematic approach to concrete repair.
Reclamation’s concrete repair and maintenance system consists of seven basic steps:
1. Determine the cause(s) of damage
2. Evaluate the extent of damage
3. Evaluate the need to repair
4. Select the repair method and material
5. Prepare the existing concrete for repair
6. Apply the repair method
7. Cure the repair properly
There are several similar repair approaches or systems currently in use. The U.S. Army Corps of Engineers (USACE) lists an excellent system in the first chapter of its manual, Evaluation and Repair of Concrete Structures. Other organizations, such as the American Concrete Institute (ACI), the Portland Cement Association, the International Concrete Repair Institute, and private authors have also published excellent methodologies for concrete repair.
The above seven-step repair system has been developed, used, and evaluated by Reclamation over an extended period of time. This process is appropriate for repairing construction defects in newly placed concrete, as well as old concrete that has suffered damage. The repair system is designed to be followed in sequential order. Reclamation has found that, all too often, the first issues discussed are how to fix a problem (what material to use) and how much it will cost. Although these questions are relevant, for an effective repair, it is more useful to know the cause and extent of damage before selecting a repair method and material.
When questions are asked in the right order, the necessary information can be obtained to design an effective repair. Of course, the information gathered must be viewed as part of a system of the existing structure, the deterioration or damage affecting the structure, and its service environment for the repairs to be as durable and long lasting as possible. Whether a concrete maintenance or repair activity is being pursued, following the steps outlined above will result in a better, more cost effective outcome.