Development of Performance Criteria for Surface Preparation of Concrete Substrates Prior to Repair and Overlay
* What are the appropriate performance criteria for surface preparation of existing concrete prior to repair and overlay?
Need and Benefit
The success of thin concrete repairs and overlays is low and hard to predict. Many times they crack prematurely, reducing the service life of the repair, and requiring expensive repairs much sooner than originally planned. A 2005 study by Kathleen Frizell, "Spillway, Outlet Works, and Water Conveyance Structure Needs - Survey Results" documents the significant issues with concrete deterioration on Reclamation water conveyance structures. In addition, a recent survey of operation and maintenance (O&M) water management training participants showed that about 30 percent of the attendees performed some level of work on concrete repairs, most of the repairs were small, and most only lasted about two years.
This lab has been working for a number of years in this area, along with partners from other government agencies, universities, material suppliers, and concrete repair specialists. While significant strides have been made identifying desirable repair material properties and methods to measure them, other important issues need to be resolved.
This problem with thin repairs and overlays is not unique to Reclamation but is reflected in the repair industry as a whole. The problem is more significant to Reclamation because of the age and quality of much of our older concrete structures, making thin repairs even more difficult.
Our existing capability is fundamentally to make thin repairs thicker, thereby increasing the likelihood of success. However, this is a time consuming and costly approach. By developing better methods for thin repairs, significant money and time can be saved.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Best Practices for Preparing Concrete Surfaces Prior to Repairs and Overlays (final, PDF,
By Benoit Bissonnette, Kurt Von Fay and Alex Vaysburd
Report completed on May 29, 2012