August 2003

Consistency is Key to Customer Satisfaction

Tight stone specs help Aggregates Industries, West Central Region win award for commercial paving.

By Angie Moehlman

Aggregate Industries, West Central Region’s Morrison Quarry installed an air classifier to clean the granite sand to provide sizing consistency.

For the last nine years, the Colorado Asphalt Pavement Association (CAPA) has sought to honor quality construction projects with recognition. At the ninth annual Asphalt Pavement Awards Best in Colorado ceremony in February, CAPA awarded Aggregate Industries, West Central Region, Golden, Colo., with the award for Best Overall Quality for a commercial project for the job it performed for the Majestic Commerce Center warehouse area in Aurora, Colo.
The Majestic Commerce Center warehouse project involved improvements to the existing entrance road leading into the area, North Windsor Drive, and the total construction of a new parking lot and dock ramp areas to service Building 23 in Majestic Commerce Center’s warehouse area. Commerce Construction, Aurora, Colo., owned the project. Aggregate Industries’ seven crew members had 60 days to complete the project and finished it with award-winning smoothness.
Aggregate Industries’ crews used a paver from Blaw-Knox to lay the parking lot’s first lift of 5,000 tons of a Superpave gyratory design hot mix asphalt (HMA). The HMA was an S grading design with 5 percent performance grade 64-22 binder.
After laying the asphalt, Aggregate Industries’ crews rolled the mat in several stages for compaction. “Our standard setup is a vibratory roller for breakdown, followed by a pneumatic roller, finished off with a static steel roller to get the tire marks out of the mat,” says John Cheever, quality control manager for Aggregate Industries, West Central Region Materials Division. Cheever says that the crew typically uses Ingersoll-Rand rollers. After the first lift was laid, crews repeated the process and laid a second lift of 5,000 tons of HMA.
The entrance road involved new construction to tie the parking lot into the existing roadway. Approximately 3,000 tons of HMA was laid in three lifts.
For the mix design, Aggregate Industries chose stone from its own Morrison Quarry, located just west of Denver. “In the mix design, we used concrete sand, crushed squeegee, and also air-classified granite sand,” says Cheever.
Aggregate Industries recently made plant improvements to its Morrison Quarry. Improvements include the installation of an air classifier, manufactured by Buell, a division of Fisher-Klosterman, Inc. The air classifier has ceramic lined chutes and processes the crusher fines at a rate of approximately 160 tph. “This allows us to take a product with 12 percent passing the #200 sieve and clean it up to 7 percent passing the #200 sieve,” says Cheever. The fine material that is removed from the crusher fines is then blended back into the structural fill product being produced, according to Cheever. “The air classifier has made the granite sand really consistent, so we have had a lot of success with that,” says Cheever.
Additionally, Aggregate Industries recently purchased an 8- x 20-ft. Deister screen to process a large pile of roadbase at its Morrison Quarry. The screen deck has 0.875-in. screens on the top deck, 0.375-in. screens on the middle deck, and a solid bottom that is used as a chute. The unit processes approximately 320 tph and produces 60 percent minus 0.75-in. rock and 40 percent structural fill. The screen deck is fed by a mobile surge tunnel that is charged from above with a dozer. The rock produced is used by Aggregate Industries’ asphalt plant in the Denver market.
To achieve an award and make the Majestic Commerce Center into the smooth, quality project that Aggregate Industries’ crews are known for, particular attention was paid to quality control/quality assurance measures. Aggregate Industries has its own quality control lab, so it can make certain that the mix adheres to the specs it was designed for. In addition to having its lab performing tests, Aggregate Industries had its own density tester on site to make sure compaction was being achieved at all times. Also, according to Cheever, “at our asphalt plants we are doing both gradation and asphalt content testing multiple times of the day.”
Tony Stoffel, project manager for project owner Commerce Construction, was pleased with the performance the crews gave on the job. “They’ve done several jobs for us in the past,” says Stoffel, “and they always do nice work and this project was no exception.”
Due to the seamless joints and smooth mat, Cheever decided to submit the project to the Colorado Asphalt Pavement Association for consideration in its award program. “I just thought that the project might be considered award-worthy,” says Cheever. “It had very straight joints that are barely visible and no segregation. The mat looks very consistent and overall, the project just looked quite nice.”
Aggregate Industries received the Best Overall Quality, Commercial Project Award at CAPA’s Best in Colorado award presentation. “We want to recognize high quality asphalt paving construction and performance,” says Rodger Young, Director of Technical Services at CAPA.
The team of judges includes a member from the American Consulting Engineers Counsel, American Public Works Association Colorado Chapter, CAPA, Colorado Association of Road Supervisors and Engineers, and the Colorado Department of Transportation. “The five of us go out and look at the projects and we try to look at them from the standpoint of the user,” says Young. “We have five categories that we rate the projects in, and they are overall appearance, segregation, longitudinal joints, transverse joints, and ride and quality. Each judge rates the job, and then we weigh that rating and average everyone’s score, and the project with the highest weighted average is the winner.”
“When you get into a parking lot or service road center area such as the one they did at Majestic Commerce Center, there can be a lot of tight corners and tough places to get into,” says Young. “Aggregate Industries’ crews did a great job; the joints looked really nice and the mat had little or no segregation. They did a really nice job of putting it down and making it look good overall.”

Aggregate Industries, West Central Region award recipients Jerry Meier (left), general superintendent, and Kevin Bartleson (center), paving superintendent, are presented the Best Overall Quality, Commercial Award from Scott Davis (right), president of the Colorado Asphalt Pavement Association.

The parking lot at the Majestic Commerce Center received two lifts of 5,000 tons each of HMA. A density tester was on site during the project to ensure crews achieved compaction.

Angie Moehlman is the associate editor for Aggregates Manager.