Micro Surfacing in Ohio
BY Olivia Kortepeter
Two technologies shine for Ohio micro surfacing of 15-year-old state park pavement preservation
Overseeing state park roads, the Ohio Department of Transportation (ODOT) is no stranger to innovative pavement preservation solutions. Maumee Bay State Park faces a climate with freeze-thaw cycles and additional moisture from lake proximity. Water can make its way into small voids and cracks in pavement, and when temperatures are below 32°F, this water freezes and expands, causing cracks to grow and compounding pavement deterioration. To combat these challenges, the park needs durable, weather-resistant pavement that does not require frequent, disruptive repairs.
After assessing the park’s current pavement conditions, ODOT identified micro surfacing as an ideal treatment. This cost-effective technique not only provides a protective barrier against oxidation and moisture intrusion, but also creates a high-friction surface to enhance year-round safety.
Maumee Bay’s existing hot mix asphalt (HMA) surface course was still in decent condition and around 15 years old, making it a good candidate for micro surfacing. By choosing the right treatment at the right time for the right road, ODOT is maximizing the life they will get from their pavement.
Nestled along the scenic shores of Lake Erie, Maumee Bay State Park is one of Ohio’s most cherished outdoor retreats. Spanning over 1,336 acres, the park offers a blend of natural beauty and recreational facilities, including over 250 campsites. Each year, its network of roads and parking lots experiences high visitor traffic from a full calendar of activities ranging from fishing and boating to cross-country skiing and sledding. Maintaining durable, safe and accessible infrastructure is essential to the park’s continued success.
PPRA’s research has shown micro surfacing—when performed with best practices—consumes less energy and reduces greenhouse gas emissions by more than 44% compared to HMA resurfacing. If the pavement is in the right stage for this process, states can use taxpayer dollars efficiently and sustainably when selecting these alternative materials and methods.
Micro Surfacing Product Evaluation
In a unique approach, ODOT used the Maumee Bay project to evaluate Ergon Asphalt & Emulsions’ (Ergon’s) eFlex®, a highly polymer modified micro surfacing treatment. Asphalt Materials, Inc.’s (AMI’s) AMISEAL™ was placed as a control section.
ODOT State Asphalt Materials Engineer Eric Biehl said, “I heard about the eFlex® product at the National Pavement Preservation Conference in 2016, and ever since, wanted to do a job with it.”
Micro surfacing consists of polymer modified asphalt emulsion with fine aggregates, mineral fillers and other additives. Ergon’s eFlex has enhanced polymer modification, compared to traditional micro surfacing treatments. It is formulated for enhanced durability, including increased resistance to tearing and scuffing of the pavement. Meanwhile, AMISEAL micro surfacing is a more traditional formulation, known for its longevity and reliable performance.
Successful Micro Surfacing Application
In October 2024, Pavement Maintenance Systems, LLC (PMS), now part of Evergreen Roadworks, placed close to 40,000 square yards of micro surfacing across eight roads and three parking lots at Maumee Bay State Park.
Prior to the application, cracks larger than 0.25-inch were sealed and the entire project received tack coat, providing a strong foundation for the surface treatment. The actual micro surfacing construction process involved mixing the materials within the paver’s pugmill mixing chamber and applying the mixture evenly across the pavement through a spreader box. This method ensures uniform coverage and a quick, efficient application.
The eFlex product was used on 80% of the project, while traditional micro surfacing, AMISEAL, covered the remaining 20% of the designated control section. Each product was placed at 22 pounds per square yard, approximately 0.25-inch thick. There was no discernable variation in the application or appearance of eFlex vs. AMISEAL.
Despite temperatures around 50°F, both emulsions set effectively. The mat began as a gray-brown color, but within an hour, the emulsions darkened—a visual cue that the mat had cured. The quick-setting nature of micro surfacing enabled PMS to complete the project swiftly, minimizing public disruption. As a final result, the pavement had a refreshed, uniform dark surface.
PPRA’s research has shown micro surfacing—when performed with best practices—consumes less energy and reduces greenhouse gas emissions by more than 44% compared to HMA resurfacing. If the pavement is in the right stage for this process, states can use taxpayer dollars efficiently and sustainably when selecting these alternative materials and methods.
Partnering with an Expert Team
Working with an experienced micro surfacing contractor proved instrumental in a successful process. PMS, with its extensive background in micro surfacing, ensured efficient and high-quality work. The on-site team included Chase Cornell (foreman) and Jason Cline (operator) with 20 and 25 years of experience laying micro respectively. PMS’s project manager Steve Willett was present to supervise the entire operation. Since 1988, PMS has been honing its micro surfacing process. In addition to the team’s collective decades of experience, keys to success include their commitment to safety, traffic control and excellent communication.
Also contributing to the project’s success were AMI’s Vince Venturella and Todd Thomas from the specialty products team. Jeff Dunn and Chris Hollenback from Heritage Research Group were present to perform additional quality control. Additionally, ODOT State Asphalt Materials Engineer Eric Biehl joined, as he initiated the introduction of eFlex to Ohio.
The micro surfacing technique not only provides a protective barrier against oxidation and moisture intrusion, but also creates a high-friction surface to enhance year-round safety.
Embracing Advanced Technology for Better Results
Micro surfacing bonds with existing pavement to form a layer of protection from moisture and oxidation—two key factors that lead to pavement degradation. This protective layer also increases surface friction, which enhances driver and pedestrian safety, especially during the winter.
The inclusion of Ergon’s eFlex as a micro surfacing option is an example of ODOT’s commitment to exploring advanced material technology. With its enhanced polymer modification, eFlex has been proven to deliver a durable, long-lasting surface with few maintenance needs. With Maumee Bay as its proving ground, ODOT will continue assessing premium products for state-wide use.
Gaining attention in the neighboring state of Indiana, rapid penetrating emulsions (RPE) are another category of asphalt product designed to extend pavement life. RPE penetrates the road surfaces and then cures, sealing off access to air voids, and mitigating the harmful effects of moisture and oxidation. This innovative product, developed by Heritage Research Group, and available as AMIGUARD™ RPE through AMI, is another tool DOTs can leverage to enhance their road networks.
Pavement preservation techniques like micro surfacing and RPE are designed to enhance the longevity of HMA, offering a more substantial method of managing pavement. As a complement to HMA, preservation treatments open the door for applicators to add new services to their toolkit. These services, in turn, allow agencies to stretch their budgets further.
While pavement preservation treatments like micro require an upfront investment, the return on that investment offers an extended life of paved surfaces. Biehl said, “Our normal micro surfacing mix lasts roughly 7-9 years on interstates and state routes, so I hope to see the same life, if not more, from eFlex.”
According to the Pavement Preservation and Recycling Alliance (PPRA), micro surfacing treatments reduce the life cycle costs of roadways by 25-45%, compared to HMA resurfacing. Overall, Maumee Bay State Park’s recent micro surfacing project demonstrates ODOT’s proactive approach to pavement management. By choosing high-quality materials, working with expert contractors and embracing innovative preservation techniques, ODOT has set a standard for long-lasting, sustainable pavement solutions that benefit both the environment and the community. The successful application of eFlex and AMISEAL at Maumee Bay will serve as a valuable reference for future pavement preservation projects across the Midwest.