Tim Woolery
For silanes to work, they must penetrate the concrete. If the so…
Just because you can’t see It …
Silanes are run through vigorous American Society for Testing and Materials (ASTM) and American Association of State Highway and Transportation Officials (AASHTO) testing before any DOT approval.
Application requires nothing more complicated than a low-pressure generator spray or pump-up sprayer, roller, pour-and-squeegee, and/or spray bars. Dry times range from 30 minutes to two hours, so impact on traffic flow is minimal. Silanes don’t affect skid resistance or pavement color.
Properly applied, they last at least six years with no maintenance. Prices have dropped by more than one-half.
Dozens of DOTs and universities globally and in the U.S. have affirmed silane performance. The question is always, “How can something we can’t see work?”
Water- or solvent-borne silane?
When introduced in the 1970s, penetrating sealer formulations were 100% silane. Silanes in and of themselves are not a volatile organic compound (VOC), but they contain VOCs. For example, a 100% silane formulation contains about 350 grams/liter. Read More
In 1976, Oklahoma became the first DOT to allow silane. Forty years later, Oklahoma State University researchers studied 360 2-inch core samples from 60 bridges. After 12 years, penetration was deeper than the state’s required 3.2-millimeter (about ? inch) minimum on all 60. After 15 years, 68% of the bridges met the requirement; 16% did after 20 years.
Silanes perform as advertised when the proper amount is specified and applied. But because manufacturers test their formulations at various application rates, it’s difficult to compare product data sheets.
Fortunately, there’s a way to write an apples-to-apples specification.
Next page: A proven rule of thumb
