Cornejo & Sons Wins KAPA Overlay Award with WMA
Using a warm-mix additive from Ingevity Corporation, North Charleston, South Carolina, the Cornejo & Sons LLC team, of Wichita, Kansas, performed an award-winning project for the Kansas Turnpike Authority (KTA) on a 16-mile section of Interstate 35 near Cassoday. The 2-inch mill and fill incorporated approximately 63,000 tons of Superpave hot-mix asphalt (HMA) with PG70-28 binder and achieved bonuses for density, air voids and profilograph readings before grabbing the 2nd place Kansas Asphalt Pavement Association (KAPA) 2018 overlay 1-inch or greater. Cornejo & Sons subcontracted the milling, then produced and placed the mix.
Since 1952, Cornejo & Sons has been serving the community, businesses and government. In 2013, the company was acquired by Summit Materials and continues to provide construction services and materials in Kansas and the Midwest. With nearly 600 employees and multiple subsidiaries, Cornejo & Sons has grown to be a vertically integrated construction materials company.
Tim Zynda, vice president of ready mix, asphalt and trucking, has been with Cornejo & Sons since 2013. He explained the company acquired a new asphalt plant in 2018 and used the warm-mix additive Evotherm for its first project with the KTA’s pavement preservation project in the Flint Hills.
“Evotherm was incorporated into the mix design as a liquid antistrip and warm mix chemistry,” he shared. “The aggregate had similar characteristics to what we’ve used in the past, and we knew Evotherm worked well with those materials. We produced the mix at appropriate temperatures and achieved maximum density bonuses.”
Zynda explained they brought in a storage tank for the liquid product, which required merely a pump tied into the controls. “The buttons were there,” he said. “Our initial emphasis to introduce warm-mix additive is we use a limestone that is an absorptive material and we would occasionally see a browning of the mix. We wanted better adhesion, wanted to get plant temperatures down, and wanted to improve viscosity. We didn’t want to cook the light ends out of the asphalt. We wanted to improve the life in the silo without drain down. The lower production temperatures [with warm mix] also help us be a better neighbor in our community by keeping emissions to a minimum.”
He explained that the most rewarding aspect of being a part of the asphalt industry for Cornejo & Sons is building:
“We like to build things. A project that goes well, rides well, where the team has gelled as a unit and brought a project in on time is one we’re proud to let everyone know we built. We spend an inordinate amount of time on quality control.”
The elements of quality control and workmanship contributed to the preservation project’s success.
“We originally incorporated Evotherm because of its adhesion capabilities,” Zynda said. “[It] allowed us to replace liquid antistrip and provided supplemental benefits…Evotherm’s ability to improve coating and workability, aid in consistent densities, and reduce mixing temperatures led to better performance and increased cost savings. Once our organization noticed the impact Evotherm made on overall mix performance, we implemented the product throughout all our plants.”
“We’re responsible for doing testing alongside a certified, independent lab running quality assurance tests,” he continued. “We have a Superpave lab with the KTA running the quality assurance tests.”
Glen Scott of KTA spoke highly of the outcome. “We were pleased with the performance of the mix. We were also very pleased with the contractor’s work during construction, which resulted in a very good ride, which resulted in a bonus payment to the contractor under a contract specification that is pretty demanding in terms of ride performance.”
“Besides Evotherm’s adhesion and coating attributes, we also discovered a lubrication property that enhances the mix throughout all stages.”
Zynda believes the lubricating properties helped achieve compaction of the mix on the KTA preservation project. “We do attribute some of the benefits to the product, but we like to think part of it is a well-balanced mix design, too. We achieved 80+ on the TSR testing and did not struggle to attain densities north of 93 percent.”
The team Cornejo & Sons has put together makes their success.
“At the end of the day, it’s all about the team working together to achieve the same result,” Zynda said. “When everyone’s clicking on all cylinders, that’s utopian in this arena. This group is solid, top to bottom. We’re proud of the team we’ve assembled here, and the quality products we use. We throughput those materials and take pride in producing a quality end product for private and public customers.”