Massive Concrete Boom Pumps Pump Largest Pour in Georgia’s Gwinnett County
Massive Concrete Boom Pumps Pump Largest Pour in Georgia’s Gwinnett CountyTwo 63Z-Meter pumps place more than 3,400 cubic yards of concrete in 17 hours
STURTEVANT, WI (October 1, 2007) – On September 8, 2007, the largest single concrete pour to-date for the Gwinnett County Department of Water Resources (GCDWR) took place for the Yellow River Water Reclamation Facility (WRF) modernization project in Lilburn, Georgia. According to the DWR, more than 3,400 cubic yards of concrete was placed in 17 hours with two 63Z-Meter Putzmeister truck-mounted boom pumps. The large slab will serve as the structural floor for one of two, new 20 million gallon water equalization tanks.
One Phase at a Time
“The Yellow River WRF modernization project is part of an ongoing upgrading and consolidation of the GCDWR’s facilities in the Yellow River Basin. This project is a complete renovation of the existing system and will provide this part of Georgia, with a new, advanced technology facility that increases the capacity of water treatment from approximately 14 million gallons per day (MGD) to 22 MGD,” says Bob Huie, project director for Pizzagalli Construction Company (Pizzagalli), the general contractor for this project. “The new facility will improve the plant’s ability in treating the water to meet new and higher standards.”
The project started in January 2007 and according to Huie, has multiple phases. Currently the project is in an early stage of the project, which includes placing concrete for, and the construction of, two new 20 million gallon equalization tanks.
“Construction of the two equalization tanks will allow the plant more flexibility in handling flow to the plant while the later phases of this renovation are executed,” notes Huie. “Later in the project approximately 40 percent of the plant will be taken out of service to construct the improvements; these tanks will then allow the plant to continue to function while the construction effort is in progress.”
According to Talamadge Mincey, area manager for The Crom Corporation (Crom) the tank designer for the project, there is only one other tank Crom has erected that is larger than the two for the Yellow River WRF.
“The only other larger tank we’ve designed holds 22 million gallons of water,” says Mincey. “But that particular tank doesn’t have a dome roof like the two new equalization tanks for this project will.”
Making it Happen
According to Huie, without the teamwork of all of the stakeholders on this project, the success of this pour and overall project would not be possible. The stakeholders include: GCDWR, the Owner: Pizzagalli, Jordan Jones & Goulding/CH2M Hill/ Precision Planning, Inc. (JJG/CH2M/PPI), the engineers; Crom; USA Readymix, the concrete mix supplier; Pioneer Concrete Pumping (Pioneer), the concrete pumping company and the testing/quality control company, ECS of Atlanta.
“The excellent communication between all of the stakeholders definitely came into play for the September 8th pour,” says Huie. “One of the biggest concerns for this large concrete placement was ensuring timely delivery and placement of the concrete.”
“There were two ready mix plants located in a very congested area of the metro Atlanta area. Given this issue, there were many unknowns on the road [traffic conditions, accidents, etc.] that could impact the work required to complete this large concrete placement,” comments Huie. “The project team decided to start the pour work for the structural floor of Tank #2 of the new equalization tanks in the late evening on Friday, when road conditions were less of an impact, and work through the early hours of Saturday.”
Crom chose Pioneer as their concrete pump supplier and operator for this project. Mincey notes that Crom chose Pioneer for this project based on successful projects with them in the past.
Placing the Concrete
While the rest of the Atlanta-area was fast asleep at midnight on that Saturday, the Yellow River WRF project team, including Pioneer’s two 63Z-Meter truck-mounted concrete pumps, started their workday for the monumental pour for the 18-inch thick structural floor of equalization Tank #2. The actual pour started at 1 a.m. on Saturday.
“After our [Pioneer] initial site inspections and pre-pour meetings with Pizzagalli, the Crom Corporation and USA Readymix, we concluded using our two 63Z-Meter pumps for this pour was the most efficient way to go,” says Chuck Maddox, sales representative for Pioneer. “We knew the versatility of the pumps would make placing the large amount of concrete for the substantial 265-foot wide footprint of the storage tank a piece of cake.”
According to Maddox, the remarkable 203' 9" vertical and 190' 7" horizontal reaches of the pumps helped immensely in completing the pour for the bowl-like equalization tank.
“The booms of both units were able to stretch and fold their first two sections of the boom vertically, fold the third and fourth sections and then extend the remaining section down, close to the body of the pump, right next to the outriggers, to place the concrete exactly where it was needed throughout the pour,” comments Maddox.
“This maneuverability of the Z-Fold booms was especially important for this pour by avoiding having to unnecessarily move and re-setup the pumps at a different location,” adds Rick Dover, a ten-year veteran operator for Pioneer. “The two pumps stayed in the same location for the entire pour which saved a lot of time.”
In addition to the impressive pumps on site for the pour, was also the impressive amount of ready mix trucks on site; about 40-50. According to the GCDWR, there was one concrete ready mix truck arriving on the project site every two minutes for a straight 14 hours during the pour.
A Mix That’s Hot
According to Maddox, his powerful pumps easily handled the concrete mix specified for the structural floor of Tank #2.
Mincey says a 5,000-psi structural concrete mix was used for the structural floor of Tank #2.
“This is a very ‘hot,’ or strong mix,” notes Mincey, “…containing 57 stone aggregate and a lot of cementitious material. This produces a concrete mix that can set up quickly, especially if the temperature of the concrete gets too warm. This further emphasized the need to keep the ready mix trucks coming nonstop during the pour to avoid a cold joint in the slab.”
This mix was specified, according to Mincey, because of required codes for these large-scale types of equalization tanks as well as the possibility of potential seismic loading conditions in the Lilburn, Georgia area.
The six-inch thick dome roofs of the two tanks require a different mix, according to Mincey. A 4,500-psi concrete mix has been specified and includes a pea rock aggregate.
“The hoop forces created by the prestressing in the dome band is responsible for supporting the free-span concrete dome.” notes Mincey. “There are no intermediate supports underneath the entire 260' diameter dome, which is pretty incredible.”
According to Mincey, next up for Pioneer’s Putzmeister pumps is to place the more than 3,400 cubic yards of concrete for the structural floor of Tank #1, which will occur in about six weeks; as well as placement of 1,500 cubic yards of concrete for each of the 260' diameter prestressed concrete domes.
In addition to the structural floor and roof dome concrete placements, according to Maddox, Pioneer will also be placing the remaining 50,000 cubic yards of concrete for the Yellow River WRF with a variety of pumps ranging from their 20Z-Meter pump to their 63Z-Meter pump.
The remaining concrete placed by Pioneer will be for about 50 percent of the base and structural slabs; 40 percent for the floors, walls and columns; and 10 percent for miscellaneous needs, according to Huie.
Pioneer will be pumping and placing concrete for this project through 2009. The entire Yellow River WRF project will be complete in 2011.