Ready-Mix Producer Uses In-House Pump Fleet To Complete 3800-yard Pour in 7 hours 2002

Cemstone Ready Mix, Inc., Mendota Heights, Minn., has maintained its familiar place in the Midwest’s concrete construction industry for over 75 years. The company prides itself in expanding their customer service with state-of-the-art pumping equipment. The contractor commissioned five of their concrete pumps to complete a 3800-yard monolithic mat pour this past August.

Widely admired as a ready mix supplier, Cemstone has expanded its fleet over the years to over 400 concrete mixer trucks. Their signature light blue truck mixers haul to job sites from plants spread throughout Western Wisconsin and Minnesota. To add to their reputation as the region’s leading supplier of concrete and aggregate products, Cemstone provides services including retail outlets, engineering, custom batching and pumping. More than 850 Cemstone employees operate and support 42 concrete batch plants, 12 contractor supply stores, 1 concrete block plant, 14 aggregate mines, 15 concrete pumps, 2 concrete reclaimers, and their truck mixer fleet.

Through their Placing Division, Cemstone is able to offer the full-service concrete construction package. Contractors appreciate the single-source responsibility that Cemstone is able to deliver thanks to the company’s fleet of truck mounted concrete pumps with placing booms manufactured by Schwing America, Inc. The fleet features seven different models of pumps with placing booms ranging in lengths from 17 to 47 meters.

Recently Cemstone’s supply and placing services as well as management and coordination capabilities were put to the test. Concrete contractor Thor Construction, Minneapolis, Minn. called on Cemstone’s Ready Mix and Placing Divisions to complete several mat pours at the Metropolitan Wastewater Treatment Plant in St. Paul, Minn. Four individual pours were completed throughout the summer months under general contractor Madsen-Johnson Corporation, Hudson, Wis. Cemstone’s truck mounted concrete pumps completed all four of the pours, each ranging between 1,300 and 1,700 yards. By August 18, two-thirds of the foundation for a new solids processing building had already been completed. The largest and final third of the pour, a 24,000-square foot area, remained. The 3,800-yard concrete foundation pour, contracted by Knutson Construction Services, Minneapolis, Minn., would require reliable equipment and careful planning with the concrete contractor and the ready mix/pump supplier.

Pre-pour management meetings by Cemstone and Thor management teams to review and plan the placements were necessary to coordinate pump set up and supply issues. Cemstone and Thor management teams met to review and plan. Division heads inside of Cemstone conducted their own in-house briefings. One major obstacle to the monolithic mat pour was the consistent supply of ready mix to the high-output pumps. Ready Mix Division representative Jack Devine said the solution was simple: more mixer trucks.

On August 19, at 2:00 a.m., Cemstone’s pumping fleet began the massive pour, relying on five of their concrete pumps. Four S 47 SX models and one KVM 39 X each pumped over 120 yards per hour, and remained stationed in their initial set-up position throughout the pour.

To supply the concrete, 72 concrete mixers from five different Cemstone plants were put through a grueling schedule. Because each mixer truck held a 10-yard load, an average turnaround of one truck per minute kept things constantly moving throughout the project. At any given minute during the 7-hour pour, 72 trucks were starting or completing their cycle, heading back to one of five plants for another load, or entering the job site to supply concrete to one of the five pumps. Devine estimated that the longest ready mix haul was a commute from Cemstone’s Burnsville location, a 30-minute transport. Most of the ready mix was gathered at Child’s Road and Midway Cemstone plant locations, a short 5-minute trip both ways. Only one washout area, measuring 130 feet by 50 feet, serviced the mixer trucks during the pour. Through the organized, cooperative effort, Cemstone trucks successfully supplied up to 600 yards of ready mix per hour, enough to keep the pumping on schedule.

"Cemstone had a 39-meter onsite as back-up, but the original five kept going," said Chris Rowe, Field Operations Director for Thor. "We didn’t shut them off until it was done." Thor crews were responsible for placing and finishing the concrete.

Besides cooperation from Cemstone mixer truck and pump operators, on-site engineers and supervisors, Cemstone plant managers and 2 dispatchers also helped coordinate the smooth execution. Along with Chris Rowe, Thor Construction President Richard Copeland commissioned Director of Concrete Operations George Fernstrom, On-site Supervisor Sean McMongial and Gary Marshall, Project Manager, to direct Thor crews. The Cemstone family was also on hand for the productive day. Tom Becken, CEO, Thor Becken, President, Tim Becken, Senior VP of Operations, and Steve Becken, VP of Aggregates remained on the job site for most of the 7-hour pour.

Daryl Gagnon, head of Cemstone’s Placing Services Division, said both pre-pour planning and reliability of Schwing pumps aided in the quick completion of the project. "We were mainly concerned with the truck turn around. Not once did we need to worry about the reliability or performance of any of the Schwings."

The mat pour provided the foundation for a brand new solids management building. General contractor Knutson Construction Services was awarded a $67 million contract for the construction portion. The new plant will house the largest fluid bed incinerators for wastewater treatment plants in the U.S., and will process waste solids for portions of six counties in the metropolitan area. The new building will replace an inefficient, older building that prompted concern from the Environmental Services Division of the Metropolitan Council (MCES), who is responsible for treating wastewater in the seven county metro area. Knutson general manager J.B. Kennedy said the scheduled date for completion is June 2004, and the target date for full-scale operation is early 2005.