Cape seals combine the benefits of two treatments for increased protection of underlying road layers by preventing water intrusion and providing a durable wearing course.

Project Details
In preparation for the cape seal project, the City, along with the selected contractor, Missouri Petroleum, proactively communicated with impacted citizens and businesses using door hangers and social media, as well as the official City of Malvern webpage. To ensure public safety in and around work areas, Missouri Petroleum also provided wooden road barriers and road closure signs.

Application Highlights
In 2020, the City was approved for a bond issue to meet the necessary investment to address isolated structural distresses before the cape seal project. In 2021, Missouri Petroleum applied a rejuvenating scrub seal using eScrub as the first layer of the cape seal to 12.3 miles of road.

During this process, eScrub, a polymer modified and rejuvenated asphalt binder, was applied over existing pavement at a shot rate of 0.30 gallons per square yard and then covered with a layer of Class 4 aggregate that was rolled and embedded into the modified binder. The use of a scrub broom forces the binder deep into the cracks, repairing mass cracking and revitalizing the pavement by returning asphaltenes into the original asphalt. The scrub seal was followed by the application of highly polymerized eFlex micro surfacing at 25 pounds per square yard. eFlex works to inhibit oxidation and provides an extremely durable wearing surface. Together, these treatments are expected to provide a minimum of 7-10 years of life extension for the treated streets.

The performance of treatments applied in 2021 and the public’s positive response thereafter led to the City cape sealing another 17.7 miles of network streets in 2022.

Results
The City of Malvern and the driving public are enjoying the finished result, including the look of freshly laid pavement and enhanced durability. “The applied combination of rejuvenating scrub seal and high-polymer micro surfacing has addressed the serious distresses our streets were experiencing and has held up well under snowplowing,” said Jacob Wright, City of Malvern Street Department Superintendent. “The treatment has greatly improved the overall ride quality and has provided a surface capable of being maintained for the next 10 years. The City is extremely pleased with the finished product and now has another tool in its pavement maintenance toolbox.”

Cost Savings
The City was able to save millions of tax dollars using cape seal as opposed to the traditional mill-and-fill approach. In addition, by sealing the high level of cracking, the treatment is expected to perform much better than a mill and overlay, where reflective cracking would have returned in 2-5 years, incurring more expense.

Long-Term Strategy
The City plans to continue to improve the overall health and safety of its streets by tracking the lane-mile-years of service life extension and documenting data within its pavement management program.