MAYO CONSTRUCTION HITS SPEC WITH HIGH TECH Intelligent compaction and paver mounted thermal profiling assist in quality paving in Bottineau County
M BY BRYCE WUORI
Modern-day paving projects are introducing multiple project requirements with more difficult specifications. It is not uncommon to find projects that have a combination of longitudinal joint density, mat density, profile milling, recycled asphalt pavement (RAP) mix design, and other requirements that all must be satisfied within the project scope. Mayo Construction Inc., Cavalier, North Dakota, understood the Highway 5 project located in Bottineau County was a modern-day paving project that would require serious attention to detail to be successful. With the number of project variables this specific project generated for the paving team, it was evident that the use of technology tools and best paving practices would be a necessity to develop a high-quality project. Mayo Construction implements paving technologies such as the paver mounted thermal profiler (PMTP) and intelligent compaction (IC) as quality control tools for improved quality in paving operations. The Hwy. 5 project Mayo Construction took on is a good example for us to focus on due to its many difficult project requirements. This specific project required a mat density average of 92% (See Figure 1), a joint density average of 90.5% (See Figure 2), a ride specification and used a Federal Aviation Administration (FAA) 45 mix design with 10% RAP produced from ¾-inch milling on the project roadway. Modern-day projects like this have a lot of moving parts that must be managed accurately to be effective. With the use of technology tools and best practices, contractors can significantly increase success rates on paving projects by eliminating variations in the field.
PROJECT ALTERATIONS FOR IMPROVED QUALITY
Project design requirements don’t always match up with the best available option for the proposed field and paving conditions. It can be difficult to understand and design a project with the number of unknown variables that can become present in the field during construction. If the contractor can present an option that will satisfy the requirements of the project—and the agency accepts it—everyone wins. When the parties involved in the project can work together toward a common objective, the quality of the road will increase for the end user and owner. The Hwy. 5 project produced a few of these situations, and the team members involved on the project were able to work together to find effective solutions. The first project alteration for improved quality on the project was allowing Mayo Construction to pave a 1-inch leveling course and a 2-inch wear course for the asphalt section. The original project design of two 1.5-inch lifts of asphalt prevented the necessary correction to the existing roadway section and brought up concerns with asphalt density and rideability of this designed section. 34 | MARCH/APRIL 2022
Willow Designs Notch Wedge System includes the notched wedge joint maker and a tow-behind rubber-tire roller.
The second project alteration for improved quality allowed Mayo Construction to increase the RAP mix design from 10% to 14%. With the inconsistency in the RAP source from the milling operations due to the ¾-inch proposed milling procedure, the contractor was allowed to adjust the RAP content to improve overall mix volumetrics, which included meeting required air void content. Working together for a common goal and understanding what variables will build a better road for the user is a must on all projects. Interactions like these are key in building long lasting smooth roads within our infrastructure system.
MILLING FOR RIDEABILITY
Milling operations for the Hwy. 5 paving project called for a ¾-inch milling depth across the entire roadway section. Mayo Construction discovered early in the milling operations that the specified ¾-inch milling depth proposed on the project was producing an inconsistent RAP source for the project and the proposed RAP mix design. Check out the article “Paving with RAP” in the February issue for tips on RAP sourcing.
Ted Billadeau, the quality control manager for Mayo Construction, commented, “This was the first time we had milled such a shallow depth of asphalt roadway to be reincorporated back in the mix design. The total ¾-inch milling performed on the centerline of the project was approximately ½ inch of asphalt and ¼ inch of chip seal, while the shoulder milling depth was averaging zero to ½ inches and was all chip seal material and very little asphalt. The varying depth of milling from centerline to shoulder can produce inconsistent RAP material.”
