The state of the paving art: the ACPA Award winners for 2004 represent the nation's best concrete pavement projects and clearly show what's possible with concrete pavement today

Concrete Construction, Dec, 2004

Overlays

1-40 Unbonded Overlay

El Reno, Canadian County, Okla.

Constructing a 10-inch unbonded concrete overlay on 6 miles of Interstate 40 built in 1967 took the overall ride of the project down from 110 inches to 0.9 inch per mile. Duit Construction proposed using a 1-inch-thick asphalt bondbreaker of a special durable mix developed with the subcontractor instead of the 2-inch bond-breaker in the plans. This reduced construction time and saved about $750,000. Duit filled in low spots with concrete instead of asphalt, enabling placement of the bondbreaker in one lift without stacking lifts in low areas.

Of primary concern was maintaining a daily traffic volume of 39,000, up to 40% trucks, and access to the main business districts of El Reno and Oklahoma City. Duit constructed temporary ramps at the major intersection and established a detour route for emergency use. The emergency route was used twice, once for an accident and once for emergency repairs on the existing asphalt shoulder.

Traffic Management

U.S. Route 202 Widening and Reconstruction

Chester and Montgomery Counties, Pa.

Upgrading an urban divided highway and its interchanges built nearly 40 years ago when traffic speeds and volumes were much lower is a challenge. The $104 million widening and reconstruction of U.S. 202 was the fourth and largest section in the Pennsylvania DOT's improvement project where traffic was highest--approximately 180,000 vehicles per day. It included interchanges with U.S. 422 and I-76 and the U.S. 202/Gulph Road intersection.

Contract plans provided fifteen control stages for the 30 months of construction. Plans were to provide at least two lanes of traffic from 5 a.m. to 11 p.m. in each direction on the three roadways. Additionally, no traffic restrictions were permitted from November 1 to March 15. An incentive/disincentive clause provided the contractor $30,000 per day (up to 30 days) for finishing construction before November 1, and equivalent penalties for finishing after November 1. In 2001, paving finished 5 days later than scheduled but wrapped up 11 days early in 2002 and 2 days ahead in 2003.

State Roads

U.S. Highway 59

Sequoyah County, Okla.

Changing an old, 24-foot-wide, shoulderless road into a five-lane, 60-foot-wide highway required using all the available right-of-way. Duit Construction planned for this 1.3-mile, highly confined worksite to maintain access to 23 businesses and accommodate an average daily traffic flow of 10,100 vehicles, including 21% trucks. That suddenly increased to 17,000, with 40% trucks, just 6 days into this project when the I-40 bridge over the Arkansas River collapsed and U.S. 59 became a designated detour.

To ensure smooth pavement, Duit paid close attention to constructing the subgrade and base. Stringline-guided CMI auto-grade equipment trimmed the 8-inch fly-ash modified subgrade. An ABG paver then used the same stringline to place 6 inches of aggregate subbase, topped with a 2-inch ACC base. Finally, dowel baskets were attached to the asphalt base and a CMI 450 paver placed the 10-inch concrete pavement, with an average smoothness of just 2.9 inches per mile.

Concrete Pavement Restoration

U.S. 90 Concrete Pavement Repair and Grinding

Hancock County, Miss.

This was the first rehabilitation of a 4.8-mile stretch of two-lane concrete pavement along the Mississippi Gulf coast since its completion in 1948. High levels of joint faulting, averaging 0.31 inch on the 21-foot-long slabs, and the extremely hard chert gravel coarse aggregate made diamond grinding and slot preparation for dowel bar retrofit very difficult.

Diamond Products' testing showed the chert to have a Mohs hardness of 9.5; by comparison, diamonds have a Mohs hardness of 10. The challenge was holding the diamonds in place on the edge of the saw blade while still getting reasonable production and blade life. Grinding subcontractor Penhall Co., Highway Services Division, used space cutting to establish a profile grade with the first pass. A second pass of diamond grinding achieved the ride and surface texture specification. The initial profile was estimated to be 60 inches per mile; following restoration, the ride quality exceeded specifications with a project average of 3.21 inches per mile.

Divided Highways--Urban

Cargo Road Interchange

Pittsburgh, Pa.

Originally, reconstructing Business Route 60 and building a new intersection with Cargo Road serving Pittsburgh International Airport's cargo handling facility was expected to take 2 years. Prime contractor Trumbull Corporation arranged a formal partnering session at the outset and proposed to have all mainline concrete paving completed in 1 year. The new schedule included a short detour and saved the Pennsylvania DOT $500,000 in temporary roadways, crossovers, and signage.

Project team members agreed to unmatched quality control measures: delivery ahead of schedule, meeting a more stringent specification than the project required, and reducing public disruption. Despite the lack of contractual incentives for superior ride quality, concrete paving contractor Hi-way Paving ran profilograph readings at its own expense The result was an international roughness index of 69.33 inches per mile, which would have passed the DOT's newest and most stringent ride quality requirements.