Permeability Compatibility Between Concrete Repair Material and Concrete Substrate
Will an impervious repair material overlaid on an older, less durable concrete substrate trap moisture and lead to further freeze-thaw damage of the substrate material and bond failures? Many of Reclamation's concrete structures built prior to the early 1950's and that are subject to harsh, cold environments, can be damaged by freezing and thawing weather. Repair materials that can withstand freeze-thaw cycles are often very dense and low permeability materials. We have anecdotal evidence that this occurs, but there is no reliable data to confirm this. This study will determine if this really occurs, and if so, what type of repair materials should be used to repair this type of damage.
Need and Benefit
Reclamation's aging infrastructure is in constant need of repair. Concrete repairs can last the remainder of the structures service life if the repair material is compatible with the existing substrate. Often times, the concrete repairs are shorter lived (5-10 years if that) because the repair material is not compatible with the existing concrete substrate. At Boysen Dam, the Concrete, Geotechnical, and Structural laboratory group is seeing repairs that were performed in 2001, that already need replacement. In addition, the concrete around the repairs have deteriorated due to freeze-thaw damage.
Reclamation has countless concrete structures in freeze-thaw proned areas that are in need of concrete repair. We know what characteristics a repair material should have to withstand freeze-thaw damage, but what we need a better understanding is how the material affects existing concrete. Gaining this knowledge will help us specify longer lasting repairs throughout Reclamation.
Reclamation is in need of the knowledge this research will provide so that future repairs can be more reliable and last longer.
Contact the Principal Investigator for information about partners.
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.
Permeability Compatibility Between Concrete Repair Material and Concrete Substrate (final, PDF, 1.0MB)
By Shannon Harrell
Research Product completed on September 30, 2018