WisDOT Study: PoreShield Reduces Concrete Pavement Damage

Wisconsin Department of Transportation (WisDOT) study shows that PoreShield, a concrete durability enhancer technology, can provide long-term concrete pavement protection from chloride ion diffusion.

WisDOT Study Shows PoreShield Reduces Concrete Damage Protection From Chloride Ion Diffusion
A worker spraying PoreShield on the I-65 highway in Indiana. PoreShield is a sustainable and cost-effective solution, derived from soybeans.

A Wisconsin Department of Transporation (WisDOT) study noted that PoreShield, a concrete durability enhancer technology, demonstrated long-term protection from chloride ion diffusion in pavement.

To measure the effectiveness of different treatments in preventing chloride ion diffusion, WisDOT funded a comprehensive study to analyze the protection of concrete joints in highways. Its findings were released in March 2020. WisDOT evaluated seven products: standard penetrating sealers (versions of silane, siloxane, poly-alpha-methylstyrene and lithium silicate) and PoreShield Concrete Durability Enhancer on select sections of Interstates 94, 41 and 39. The study demonstrated that PoreShield was more than twice as effective as the penetrating sealers in reducing chloride ion diffusion when measured at least 0.5 inches below the surface.

WisDOT Study Shows PoreShield Reduces Concrete Damage Protection From Chloride Ion DiffusionReduction in Chloride Ion Concentration, Wisconsin Department of Transportation StudyWisconsin Department of Transportation | PoreShield

“Although PoreShield is often compared to penetrating sealers, it performs very differently,” says PoreShield Technical Consultant Paul Imbrock, who helped develop PoreShield. “As demonstrated in this study, PoreShield is not only more effective at reducing chloride ion diffusion, but it also increases the service life to concrete five-to-nine times longer.”

What is Chloride Ion Diffusion?

Chloride ion diffusion is one of the leading culprits of concrete highway damage. This is most often a result of deicers applied to highways, meant to keep roads safe from snow and ice. Common deicers such as Calcium Chloride (CaCl2) are effective at melting ice and snow at lower temperatures. However, CaCl2 doesn’t go away after the ice melts.

Deicers are primarily used in the winter months to keep pavements safe for travel. These chemicals are absorbed and ions diffuse into the pore network of concrete where they build up over time. In the warmer temperatures of spring, summer and fall months, these ions react with the calcium hydroxide that exists in the pores of all concrete. This reaction forms a product called calcium oxychloride, which expands and causes damage year-round.

Because PoreShield fills the concrete pores, it blocks the absorption and diffusion of ions and keeps deleterious ions, such as CaCl2, at the surface. This deters year-round calcium oxychloride formation which is a root cause of concrete damage stemming from winter deicers.

PoreShield is ideal for major highway projects, bridge construction and other large-scale roadway infrastructure applications. Unlike any other existing method, PoreShield does not undergo a chemical reaction or solidify. It is a soy methyl ester-polystyrene (SME-PS) material that remains fluid and protects concrete from the inside out with a flexible, hydrophobic barrier that is absorbed deep into the pores. With preventive and self-healing properties, this barrier stops any existing damage and deterioration from getting worse. This barrier makes PoreShield the most durable solution available to protect concrete against water, salt and freeze/thaw damage.

In addition to high performance, PoreShield is a sustainable, hazard-free and cost-effective solution. It is derived from soybeans, a renewable resource. It is low in VOC and reduces application time. PoreShield requires no personal protective equipment and eliminates the need for hazardous waste cleanup. Not only is PoreShield safer, faster and sustainable to use, it is also a smart investment. With reduced application and maintenance costs, combined with 10 or more years of protection, PoreShield is a cost-effective concrete durability enhancer for every budget.

This research was funded through the Wisconsin Highway Research Program by the Wisconsin Department of Transportation and the Federal Highway Administration. The full report is available at wisconsindot.gov/documents2/research/0092-18-01-final-report.pdf.