Tag Archives: Atkins

Municipal Streets & Intersections >30,000 SY (SILVER)

Lindsey Street (from 24th Ave. SW to East of Berry Rd.), Norman, OK
Contractor:  Sherwood Construction Company
Owner: City of Norman 
Engineers: Poe & Associates, Inc. and Atkins

This important stretch of roadway is lined with restaurants, businesses and homes, and is also a vital like to the University of Oklahoma.  With about 25,000 vehicles (including delivery trucks) using this roadway every day, it’s easy to see why there was a lot of attention on this project.

This project was the second portion of a major upgrade to this important corridor. After citizens of Norman approved a major bond issue, crews went to work on utility relocation and other work, including the upgrade of a water line through this area.

Sherwood Construction coordinated closely with hundreds of businesses located along the corridor to maintain access throughout the whole project. The project was phased almost as if it were two separate projects.

The contractor first established a detour by removing the existing curb, then connecting all the driveways with a 6 in. fiber reinforced concrete pavement on untreated base.

To construct the base, Sherwood used a modified cement-treated base/econocrete base, which they developed to allow the use of ready mixed concrete. Placing the econocrete base with a slipform paver had its challenges because of it was only 4 in. thick. To meet the challenge, Sherwood developed a sliding rail forming system to place the material by hand. Pins where set on grade and a steel channel was set on the pins.  The channel would slide from pin-to-pin and served as a strike off for base material. 

The contractor moved traffic out to install a new storm sewer system which, at some locations, was an 8 ft. x 7 ft. box that was almost 20 ft deep to the flowline. The replacement storm sewer extended to two side streets to alleviate flooding in the residential areas north of the corridor.

Sherwood then detoured traffic to one side of the grade to construct half the new driveways and the 8 in. jointed plain concrete pavement.  The traffic was then moved to the new pavement to allow construction of the other half of the roadway.  Next, the median and islands were constructed to complete the middle of the roadway.

Slipform paving proved to be challenging.  String line was set to get the most productive run of each paving section, typically from intersection to intersection. The contractor would then block out alternating driveways to maintain access to the businesses.  The block-outs would be poured by hand later using a high early strength concrete mixture that would allow for re-opening the driveways 24 to 48 hours later.

This high-profile project required excellent communications.  The City of Norman had several public meetings before the project started to inform businesses and residents along the project of the upcoming work.

During construction Sherwood and the engineers would meet with city officials on a bi-weekly basis to go over project schedule.  Businesses or residents that were would also be notified in advance of work, and in time for city officials to issue press releases and media advisories about upcoming closures or traffic switches.

The contractor earned a $400,00 incentive for early completion of the project and now, local residents and roadway users have a long-lasting, high quality concrete that will serve this busy corridor for many years to come.

Commercial Service & Military Airports (GOLD)

Taxiway Pavement Replacement at Hartsfield-Jackson Atlanta International Airport, Atlanta, GA
Contractor: McCarthy Improvement Company 
Owner: Hartsfield-Jackson-Atlanta International Airport
Engineer: Atkins

Completing any construction project at the world’s busiest airport would be a challenge, but when ATL airport needed three taxiways and adjacent shoulders replaced, McCarthy Improvement Company met the challenges by delivering a quality concrete pavement reconstruction project.

The total contract was $23.7 million, with the concrete portion accounting for more than $5.1 million. In all, the work was completed in 10 phases. The overall project duration was 330 calendar days, with liquidated damages set at $100/minute for any delays in reopening taxiways as specified, as well as $3,000/day penalties for exceeding the 330-day schedule.

The demo sections depth varied from 16.75 in. to 22 in. During one phase of the demolition, crews found and removed two layers of concrete with strength at or above 3,000 psi.

The taxiway pavement replacement project consisted of full depth replacement of portions of three taxiways. In all, the work included 38,000 SY of concrete paving removal, new centerline lights, subgrade repairs, new underdrain system, and a complete rebuilding of asphalt shoulders.

The typical new taxiway section was comprised of new underdrains trunk lines and herring bones, new light can conduits & light cans, a P-401 bituminous leveling course on top of 6 in. of soil cement, fully rebuilt asphalt shoulders, and a 20 in. concrete pavement. The non-reinforced/reinforced concrete thicknesses were: 20 in., 20 to 26 in. thickened edges, and 16 to 20 in., and a 16 in. shoulder ramp.

Typical slab sizes were 25 ft x 25 ft, with two of the phases having outside slabs measuring 12.5 ft wide 25 ft long. The smaller slabs were reinforced, slip-formed, and extended for a total length of approx. 900 linear ft in one phase and 725 linear ft in another.

The required straight-edge smoothness was 12 in., with a maximum 0.25 in. deviation on 16 ft with anything over 0.5 in. removed and replaced. Despite the presence of new light cans installed in the center-line lanes, as well as intersecting taxiways, the concrete met the smoothness requirements with no grinding.

One of the keys to the successful completion of this project was the extensive planning and coordination, which ensured all the construction traffic and related operations were contained in the designated work area, thereby avoiding the disruption of airport operations. Haul routes were clearly marked on drawings provided to escorts and haul-truck drivers.

Scheduling was done for each hour of every 24-hour workday, which was divided into 12-hour shifts, with a 1-hour overlap for the crews. The project also benefited from strong support by the owner and engineer, along with real-time decision making to address unforeseen conditions, along with the contractor’s ability to adjust operations efficiently.

Expert planning, communications, and paving resulted in this project being completed on time. Thanks to this team effort, the three durable, concrete taxiways can be expected to meet the demands of this busy and bustling airport for many years to come.

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