Mayo Construction Hits Spec with High Tech

Intelligent compaction and paver mounted thermal profiling assist in quality paving in Bottineau County

BY BRYCE WUORI

MModern-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.

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.

Willow Designs Notch Wedge System includes the notched wedge joint maker and a tow-behind rubber-tire roller.

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.”

Caterpillar AP1055F paver with SE60 screed and PMTP

Mayo Construction performs a slate of best practices during milling operations and understands the importance of producing a good RAP source for the RAP plant mix. The one best practice the milling operation performed that assisted immensely on the Hwy. 5 project was the use of a milling machine with a 14-foot mill head. This allowed the RAP source to be managed more accurately in the field with a single machine performing the pavement extraction and allowing one single pass in each lane from the milling machine to reduce inconsistencies and improve rideability of the milled surface.

Precise milling operations will produce more consistent RAP sources and increase the ride of that existing roadway for the paving operations. Inconsistencies in milling sections on the roadway and RAP sources from the extraction operations can ultimately result in reduced rideability and inconsistent RAP plant mixes on the project. Performing best practices during the milling operations will assist in making any RAP paving project go more efficiently from start to finish. These practices and procedures are confirmed by projects that produce large amounts of success like the Hwy. 5 project.

THERMAL PROFILING

The paving team at Mayo Construction incorporated a Topcon FC6000A thermal profiling unit mounted on a Caterpillar AP1055F paver and SE60 screed. Having the ability to monitor the thermal uniformity of a newly placed asphalt mat with a thermal profiler is game changing when it comes to quality control. This is especially true when paving with RAP mixes and in cooler ambient paving temperatures. Being able to see what happens to the uniformity of the mix behind an asphalt paver as project variables such as plant production and paver speed are modified, will ultimately assist the quality control team in finding the “sweet spot” in the operations where quality can be achieved.

PMTP technology also assists in training and showing paver operators the importance of keeping consistent paving speeds and reducing paver stops. Paver stops create thermal inconsistencies in the asphalt mat and impact the performance of the rolling train, which is very crucial in constructing smooth uniform dense roads. Bumps in the road can be developed from paver stops and roller stops. Eliminating the number of these stops will increase better average densities and build a smoother road.

Billadeau said, “We always try to match the paver speed with the plant production rate to minimize pave stops. Being our first time using the PMTP, we did not know what to expect. Once the PMTP system was set up, the paver screed and speed were adjusted to maximize the consistent temps across the mat behind the paver. The final PMTP and IC data was immediately turned over to the DOT for their use after the project.”

The paving team at Mayo Construction Inc. had great success implementing the PMTP as a quality control tool in the field. “The Topcon system was very user friendly and easy to manage in the field,” Billadeau said.

Technologies like the PMTP assist the users in identifying quality control parameters for paver and roller setup. Without technologies like intelligent compaction and the PMTP it is almost impossible to see thermal segregation behind the paver or areas on an asphalt mat a roller may have accidently missed. Technology tools are designed and developed to assist the user in understanding variables that are difficult to identify with conventional means in the field. The desire to use technologies as quality control tools in the field is steadily increasing within the paving industry. When paving technologies can be applied and managed properly, users will develop enhanced quality in the field and produce more project success.

INTELLIGENT COMPACTION

The Mayo Construction paving team has used IC technology on many mainline projects over the past few construction seasons, including the Hwy. 5 project.

“Basically, each roller operator can watch the screen to see the areas compacted and set up rolling patterns,” Billadeau said. “This system ensures that the entire roadway gets rolled as consistently as possible while not missing any areas.”

FIGURE 1. TABLE 430-13 EXPLAINING NDDOT REQUIRED PAVEMENT DENSITY ADJUSTMENT FACTORS FOR FAA 44 AND 45

ADJUSTMENT FACTOR

1.05

AVG. PAVEMENT DENSITY1

> 93.6%

1.03 93.1% - 93.5%

1.00 92.0% - 93.0%

0.98

0.95

0.91 91.0% - 91.9%

90.5% - 90.9%

90.0% - 90.4%

0.85 89.5% - 89.9%

0.70 89.0% - 89.4%

North Dakota DOT’s required pavement density states the engineer is to apply adjustment factors from Table 430-12 for lifts of pavement placed on aggregate base, reclaimed material or cold in-place recycle material. Table courtesy of NDDOT

FIGURE 2. NDDOT REQUIRED JOINT DENSITY CONTRACT PRICE ADJUSTMENT PER LINEAR FOOT JOINT LOT % MTD

$0.40 > 91.1% $0.20 90.6% - 91.0% $0.00 90.0% - 90.5% $(0.20) 89.0% - 89.9% $(0.60) 88.5% - 88.9% $(1.10) 88.0% - 88.4% $(1.80) 87.5% - 87.9% $(3.60) 87.0% - 87.4%

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Having consistent rolling patterns and the use of IC can be a key step in developing uniform and smooth asphalt roads.

The rolling train for the Hwy. 5 project consisted of a Caterpillar double steel drum roller in the breakdown position, a Caterpillar pneumatic roller in the first intermediate position, a Dynapac double steel drum roller in the second intermediate position and a Dynapac double steel drum in the finish rolling position. With cooler ambient paving temperatures and the difficult density requirements this project specified, the paving team used a combination of technology, experienced roller operators and good quality equipment to successfully achieve required density on the Hwy. 5 project.

PROJECT SUCCESS

Management commented, “Our Crews at Mayo Construction work very hard and take pride in doing the best they can. The employees understand that it takes the entire crew from the flaggers and pilot car to truck drivers, dump man, paver and screed operator, and everyone through the final finish roller operator to accomplish a smooth ride on ride spec projects. Their commitment to achieving a bonus ride is through dedication and working as a unified team for a common goal.”

The management team in the field that assisted in a successful project consisted of: Ted Billadeau, quality control manager; Jon Newman, project manager; and Stuart Uhlenkamp, project superintendent. Establishing common goals that team members can strive toward is a great way to develop team unity on your next paving project. When a contractor takes pride in what they do, as Mayo Construction does, this passion reflects through in the workmanship of the road being constructed. Team unity, common goals and pride in workmanship will help produce a high-quality constructed road. The Hwy. 5 project for Mayo Construction is a prime example of this theory in practice.

Recognized in North Dakota for delivering the best ride quality project in 2021, Mayo Construction has a lot to be proud of. The project received the North Dakota Ride Quality Award, which is presented by the North Dakota Department of Transportation and the Dakota Asphalt Pavement Association. This was announced at the Dakota Asphalt Pavement Association Conference in January 2022, but the award will be given to Mayo Construction at the North Dakota Asphalt conference March 2.

“It’s always rewarding to be recognized by the industry for a job well done,” Billadeau said.

The paving team at Mayo Construction recorded a 33.4 IRI on the eastbound lane and 30.6 IRI on the westbound lane. Other project successes included achieving a 93.3 average for the mat density and a 90.7 average for the joint density. Mayo Construction used the Willow Notch Wedge System on the project and implements this tool on every project that requires joint density.

As evidenced by these numbers, hard work pays off. The Mayo Construction team balances best practices in the field, quality control with technology tools, team unity and dedication to continuously develop successful paving projects.

Bryce Wuori is the owner of Wuori Consulting and the developer of PaveWise™ and Dynamic Density Design. He studied construction engineering at North Dakota State University and holds a Master of Project Management. For more information, contact him at bryce.w.wuori@gmail.com.