Night Moves
Updating a 50-year old elevated highway in a congested urban area is a delicate job requiring deft moves to avoid the constant flow of traffic and other construction equipment wedged onto the construction site. When the job also requires completely rebuilding 12 bridges – one with a river crossing – the job takes on new proportions for concrete pumping with long booms to reach piers in the water and decks above. Add the complication of pumping at night in summer to keep concrete in spec and ready-mix trucks moving and you have a description of the final phase of the I-75 Modernization Project in Ohio. Buckeye Concrete Pumping, Middletown, Ohio has been on the project for a year with more than three years to go on the final stretch in downtown Dayton.
Kokosing Construction, Fredericktown, OH, is the general contractor for phase 2. This final phase will connect two earlier phases at the northern and southern ends of the project. Kokosing value engineered the project for the State and saved the taxpayers some money by converting steel beams to concrete. This also makes the construction sequence go a lot smoother, according to the contractor. The company’s Heavy Highway division is responsible for the I-75 project but the company is proud to note that any, or all, of their six divisions – Heavy Industrial, Asphalt, Utility, Marine and Equipment – can be concentrated on one project.
Buckeye is equidistant from Cincinnati or Dayton allowing a short 30-minute drive to their two largest markets. According to Joshua Craiglow, Buckeye vice-president of operations, “We schedule for the project as if we are going to be pumping around the clock.” The company’s fleet of Schwing boom trucks includes machines from 31 to 52-meters as well as line pumps. “We have at least one pump on the project four to five times a week, “ Craiglow adds. This is the second year that the company has been pumping on the project. “Most of the substructure is pumped with our 32 and 39-meter boom pumps,” Craiglow says, “Pours range from 100 to 350-yards and occur three times a week.” Most recently the pumping has included stem walls and pier caps which have been within the reach of the company’s 39-meter pumps.
There are 14 piers being constructed in the Great Miami River, according to plans. Kokosing elected to build cofferdams and causeways to allow the pumps access to nine pier locations. The concrete pumps’ booms were able to reach into the 16-foot high, three-foot diameter caissons to pump the piers that support a three-foot thick pumped stem followed by a cap of equal thickness. The two 1500-foot spans will carry three lanes south and two lanes north.
As the construction has progressed, pumping has moved overhead requiring longer booms. “In order to minimize moving the pumps, we have 45, 52 and 61-meter booms on the deck pours,” says Craiglow, “We have a good relationship with Ramcrete who brings their long boom to the job when needed.” Ramcrete is located in Hamilton, OH, northwest of Cincinnati. They operate a versatile fleet of Schwing boom pumps from 31 to 61-meters. Buckeye owner, Terry Craiglow has enjoyed a 30-year relationship with Ramcrete owner Ron Morgan. Both pumpers have sons actively involved in their companies. “We compete, but we also work together which helps foster the growth of pumping in our area,” Terry states, “As long as our customers are getting good service, it pays to share some of the work.”
Buckeye’s S 52 SX Schwing pump with 170’7” vertical reach and 158’2” horizontal reach operating through a RZ5 Overhead Roll and Fold 5-section Z boom allows the operator to rotate the boom 370-degrees pouring smoothly in front of the paving machine. The 2525H-6 pump kit utilizes a pair of 10-inch diameter pumping cylinders with long 98-inch strokes providing up to 213 cu. yds. per hour. “The result is a near continuous flow of concrete which is great for the finishing crew to screed off and maintain the paving process,” Josh Craiglow notes, “Kokosing uses a 100-yard per hour rule but we often get over 135-yards per hour out of the pumps which is only limited by the ready mix trucks .” Kokosing has been using Buckeye for a long time with good results, according to a company representative.
Deck pours are designed to keep pump movement to a minimum but when the pour schedule requires coverage beyond one set-up, the pumps are hopscotched along one side of the elevated roadway to keep two pumps working at all times. “Both the S 52 SX and S 61 SX have Super X outriggers that deploy quickly which aids in this process,” according to Craiglow. The pumps also incorporate MPS – Multi Port Switching – which eases the material cylinder into the forward stroke to reduce the pounding noise that some pumps create. The MPS also keeps the boom stable even at maximum output.
“Our operators are able to maintain pumping efficiency with the Vector controls which are standard on the Schwing pumps, “ Craiglow states, “They can be positioned on the bridge deck and monitor the pumping process through a readout on the wireless remote control box. It keeps them pumping instead of returning to the pump to check on operating status.”
Night pours are a regular occurrence on the project when high ambient temperatures threaten to overheat the concrete. Reduced traffic also helps speed ready-mix trucks along the 15-mile trip to the site. The producer mixes with 56-degree well water that helps extend the setting time, but occasionally they add ice or retarder to the mix in high temperatures and humidity. The mix is a QSC – Quarry Sand Concrete – that enables the high-performance 4500 psi concrete to reach compressive strength and pour at a six or seven-inch slump.
The marathon project is scheduled to be completed in the Fall of 2017. Pumping is ongoing and for Buckeye it is a regularly scheduled project for at least three pumps. Night pours begin at 7:00 p.m. with the plan to finish up around 6:00 a.m. the following morning. Which means there are a lot of Buckeye pumps burning the midnight oil, especially on a recent weeknight when they were also working on three other bridge projects.
Specs:
Project: I-75 Modernization Project, Dayton, Ohio
Owner: Ohio Department of Transportation
General Contractor: Kokosing Construction, Westerville, Ohio
Pumping Contractor: Buckeye Concrete Pumping, Middleton, Ohio
Pumping Equipment: S 32 X, S 39 X, S 45 SX, S 52 SX, S 61 SX Schwing truck-mounted concrete pumps with placing booms
