This was not a MARKHAM project. In fact, it was carried out immediately before MARKHAM began working with hydrogel treatments for concrete. Information on the project and an independent assessment of the results were provided to MARKHAM as part of our own enquiries on the effectiveness of hydrogels, and it remains a remarkable example of the practical effectiveness of these treatments.
The Challenge
In their current form, the Ruskin Dam and powerhouse, in British Columbia, Canada, were originally constructed in 1929. More information on the history can be found at the BC Hydro website.
The area in question was the interior of the electrical house, below the dam’s water level, where pressure seepage, or ‘hydrostatic weeping’, was increasingly occurring. The expression ‘serious water leakage’ was used by the examining consultant. This was, of course, a significant concern as regards the long-term stability of the structure, and the objective was to arrest the ingress of that water.
Solution and Outcomes
In 1997, the concrete interior of the electricity house was treated with colloidal silica hydrogels, spray-applied by atomization in all affected areas. Two rounds of treatment were necessary.
The seepage was effectively blocked at all points, demonstrating how hydrogel treatments immobilize moisture and can help preserve the durability of affected concrete. After the first treatment, the moisture ingress was reduced to ‘minor weeping’, and after the second treatment the wall became dry and was able to be re-painted.
The project was independently assessed by Canadian consultants Gordon Spratt and Associates, along with a testimonial from the Orlando Utilities Commission who managed the hydroelectric facility. The Gordon Spratt summary which came to MARKHAM states:
“Our testing program indicates that the product is capable to decrease the permeability of concrete. After reviewing both the Ortando Utilities Commission letter and American Masonry Protection test results, in conjunction with our extensive test program and use of the product, it is our opinion that the … Concrete Preservation Treatment, if applied correctly, will enhance the performance of the concrete as stated in these particular situations.”
This report was influential to MARKHAM taking on concrete hydrogel treatments, a technology which was virtually unknown in the industry at that time.
A more detailed case study download is available here.
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Photograph courtesy BC Hydro
