Dual Roles Give Southern Concrete Materials an Edge on Restrictive Job Site October 2007
Company supplies and places concrete for the I-4401 Buncombe County Design-Build project
STURTEVANT, WI (October 1, 2007) – To the locals in Asheville, North Carolina, the merging of I-26 and I-240 into I-40 is known as “malfunction junction.” With the increasing congestion at this busy interchange, drivers face hazardous conditions that have resulted in a number of traffic accidents. The North Carolina Department of Transportation (NCDOT) is responding with a solution to alleviate the ongoing traffic issues with the help of Asheville-based Taylor and Murphy Construction (T&M).
An Innovative Solution In 2005, the NCDOT chose T&M to design and construct additional lanes along I-40 in Buncombe County. According to John Herrin, construction project manager for T&M, the project started in 2006 and will include five phases: •Phase I: Construct two lanes in the existing median throughout the project; replace signals along US 19/23 at ramp interchanges; complete the Intelligent Transportation System (electronic warning system for drivers) and use the system for remaining phases.
•Phase II: Place the existing two west bound lanes into the newly constructed median lanes; construct a new outside auxiliary lane; overlay the existing two lanes on the I-40 west bound lane.
•Phase III: Place the two west bound lanes from the median onto the two new west bound lanes completed in Phase II; place the two east bound lanes into the median lanes; construct the new outside auxiliary lane; overlay the existing two lanes on I-40 east bound lanes; complete the Sound Wall along I-40 east bound lane.
•Phase IV: Place the two east bound lanes from the median into the three new eastbound lanes completed in Phase III; construct the permanent median barrier rail throughout the project and complete the median lanes.
•Phase V: All four lanes open in each direction.
Currently, the project is in Phase III.
“One of the key reasons T&M was chosen by the NCDOT for this project, was because of T&M’s innovative ‘Design-Build’ approach to the extreme congestion issue on the interchanges,” says Herrin. “This approach allowed us to hire design firms to design the project, while simultaneously proceeding with construction before the final design plans are complete.”
T&M chose Florence & Hutcheson, Inc., as the roadway design engineer and Ralph Whitehead Associates as the structure design engineer for the project.
Herrin says going with this approach saves a considerable amount of time and money by allowing the contractor and the engineer to develop an optimum plan from the start.
“The project will be complete two years earlier than if a traditional construction approach had been used on this project,” comments Herrin.
Doubling Up T&M chose Asheville-based Southern Concrete Materials (Southern Concrete) as the project’s primary concrete and concrete pump supplier. Southern Concrete has been in business since 1958 and notes that T&M is one of their biggest customers.
“One of the key reasons we chose Southern Concrete is because they’re a responsible and honorable supplier who takes great care in furnishing and delivering both a product and service that are well above average for the industry. The company is a true leader in western North Carolina,” says Herrin. “With Southern Concrete not only providing the concrete boom pumps but also supplying the concrete for this project, we have established a great rapport which only helps to expedite progress on the project even more.”
According to Herrin, a total of 30,000 cubic yards of concrete is needed for the I-4401 Buncombe County Design-Build project. About 10,000 cubic yards of the total amount of concrete will be pumped and provided by Southern Concrete.
“The remaining 20,000 cubic yards of concrete needed for this project is for the various concrete pavement needs,” notes Herrin. “Southern Concrete has and will provide some of this concrete when certain situations call for it.”
Southern Concrete arrived on the job site in 2006, according to John Holt, vice president and Hendersonville, North Carolina, division manager for Southern Concrete, with their two Putzmeister 36Z-Meter truck-mounted boom pumps and Putzmeister 43Z-Meter truck-mounted boom pump. The pumps will place 5,000 cubic yards, of the total 10,000 cubic yards of concrete, for the bridge spans and the west and east sections of the project, according to Holt.
“One of the other key reasons we chose Southern Concrete for this project is because of their dependable Putzmeister pumps,” notes Herrin. “In all my years working with them [Southern Concrete] we’ve always had success with their Putzmeister equipment. The versatility and adaptability of the pumps, especially on this extremely space restrictive site, is amazing.”
Pumping in a Challenging Environment According to Herrin, the project’s location is so restrictive because, “the location of the project is right in the middle of a developing urban area where we’re rebuilding a main artery for the traveling public in Asheville and also rebuilding a major truck route to the east and west. The Norfolk Southern Railway creates another challenge because it runs right through the project area. With limited room and this project surrounded with environmental concerns it’s a big deal just positioning equipment as well as logistics for the smallest scopes of work.”
The environmental concerns Herrin references refer to the environmental wetlands and historical areas around the project site that cannot be disturbed by the ongoing construction of the project.
“We cannot interrupt the trains using the Norfolk Southern Railway, so we have to work around the train schedules,” says Holt.
In July 2007, Southern Concrete’s team placed concrete for the westbound bridge span that goes directly over the Norfolk Southern Railway.
“We placed approximately 250 cubic yards of concrete for this pour with our 43Z-Meter pump,” says Holt. “We had to carefully choose what location would be best to position the pump because of the close proximity of where the concrete needed to be placed and where the railroad is located.”
The 43Z-Meter was placed right next to the westbound side of the bridge and directly next to the Norfolk Southern Railway.
“The pour lasted about 16 hours because of having to stop pumping to wait for trains to pass through periodically on the railroad during the pour as well as other various factors concerning the site conditions. This is a very long time considering we only placed 250 cubic yards of concrete,” notes Holt. “But this is a good example of how challenging this site is and how versatile the 43Z-Meter is in restrictive environments. Without the 43Z-Meter’s flexibility and ability to setup quickly on restrictive job sites, the pour would have been much tougher and much longer.”
According to both Holt and Herrin, even with the long time frame of the pour in July, there were no problems with the delivery or placement of the concrete.
“We were able to control concrete set time by using admixtures in the concrete mix,” says Holt.
“The delivery and placement of the concrete for this pour was carefully planned out by Southern Concrete and T&M; therefore eliminating any potential problems with the delivery and placement of the concrete,” adds Herrin.
In addition, Holt says the impressive 138' 5" vertical reach and the five-section Z-Fold design of the pump was an unquestionably huge asset to have for this pour and will be for other pours on the project.
“The extended reach of the boom pump’s Z-Fold design allowed us to place the concrete exactly where it needed to be placed, even in the most restrictive environment.
“In addition, our two 36Z-Meter boom pumps have pumped various sections of the westbound bridge. The four-section Multi-Z boom design and 116' 9" vertical reach has also been impressive, along with its compact footprint on-site and its powerful pumping performance of up to 210 yd3/hr. No matter which pump we use, we really can’t go wrong.”
The Mix The concrete mix for the west and eastbound bridge spans are a NCDOT specified mix at 4,500 psi and is a Class AA mix, according to Holt. The mix consists of cement, flyash, 3/4" stone, natural sand and admixtures.
The concrete mix for other work on the project; such as mat slabs for the medians and auxiliary lanes is also NCDOT specified and is a 3,000-psi concrete mix.
Holt says their pumps have been handling the mixes with ease.
What’s Ahead According to Herrin, the project is close to being right on schedule. Next up on the project’s timeline is Phase IV; placement of the barrier rail throughout the project on inside shoulders and the west and eastbound sections of the bridge and roadwork inside the median will begin.
Southern Concrete will be on the project for about another year. Their next task is placing concrete with their pumps for the west and eastbound lanes that will occur from winter 2007 through spring 2008.
Herrin says of Holt and his team on this project as a whole, “The management of Southern Concrete as well as its personnel and equipment have made this project a lot easier. Their drive to produce quality and excel in safety has been a true asset. On behalf of T&M, I thank them for a great job and look forward to many more.”
Set for completion in fall 2008, the I-4401 Buncombe County Design-Build project will relieve drivers of most of the malfunction occurring in the junction of I-26 and I-240 into I-40.