By Mark Rea

Motorists making their way north from Dallas toward the Oklahoma border along U.S. Highway 75 will soon enjoy a smoother ride.

Although the $46 million reconstruction of a 10-mi. stretch of the highway in southern Grayson County between Van Alstyne and Sherman is not scheduled to be completed until early 2005, the Texas division of general contractor Duininck Bros. Inc. believes the project could be finished several months early.

"This project is moving along at a very good pace," said Ken Santjer, project superintendent for Duininck Bros. "I think we're going be finished by the fall of 2004."

The U.S. 75 reconstruction began on the TxDOT drawing board as a simple refurbishing project with hot mix asphalt as the desired pavement topping. But the roadway had been overlaid with HMA in the late 1980s, and experienced severe rutting problems especially in the northbound lanes.

TxDOT ordered another overlay project in 1994, but it did not alleviate the rutting problems. When it came time to resurface the highway again in 2002, the state highway department opted for complete reconstruction.

"The project was originally designed to remove all of the asphalt pavement and replace it with a newer design, perhaps a stone matrix configuration," said TxDOT Sherman area engineer Bobby Littlefield. "But we eventually decided to completely rebuild that section of the highway."

The highway was initially built in the early 1960s with design specifications of the time that included shorter access and egress ramps for slower speed limits. "We felt the time was right to go ahead and design for up to 70-mph speeds, and make this highway compatible for a future six-lane facility," Littlefield said. "So we scrapped our overlay concept and went with a complete reconstruction."

The new, safer design for faster speeds could help qualify U.S. 75 for redesignation as an interstate highway in the future.

"There is a lot more that needs to happen before that takes place, but one of the requirements is that the controlled-access freeway feature a 70-mph design," Littlefield added. "This is not necessarily the first step - it's just one step. But we felt if we were going to spend the money to rebuild this section of the highway, why not go ahead and spend a little bit more and bring it up to meet that design speed criteria?"

Getting Started

Construction began on the five-phase project in April 2002 with detours being built for both northbound and southbound traffic. "We actually widened the highway in both directions to make room for two lanes of detoured traffic," Santjer said.

In the second and perhaps most difficult phase, work crews installed a new roadway course over what was the grass median that divided the existing four-lane highway.

"Anytime you have to close lanes and reroute traffic, it's tough," Santjer said "We had to wait for traffic-control personnel to set everything up to be able to go to work in the morning, then we had to quit early enough in the evening to get everything down for the afternoon commute. It made for some slower going in the beginning stages."

Once the middle section was completed, work on the southbound lanes began with demolition of the existing 8-in. pavement. The old course was removed and crushed, then recycled back into the base course of the project.

"We cement-treated the course and the subgrade, then overlaid that with a 1-in. hot mix layer and 13 in. of continuously reinforced concrete pavement," Santjer said.
Crews used a variety of conventional concrete mixes, provided by McKinney-based Lattimore Materials Co. and mixed at Duininck Bros.' onsite portable batch plant.

Once complete, the project will contain more than 626,300 sq. ft. of concrete. In mid-July work crews totaled approximately 100 working average 6-12 schedules. Santjer estimated the workforce and schedule will continue throughout the remainder of the project.

Paving Particulars

In mid-July, workers were setting their sights on completing reconstruction of the southbound lanes and getting ready to concentrate on the northbound section.

Crews from Roanoke-based J.L. Steel LP are handling installation of the reinforcing steel for the project, which was supplied by the Lofland Co. of Fort Worth. Workers install No. 5 and No. 6 rebar approximately 6 in. apart with transverse bars placed every 24 in.

Following behind the rebar crews is the paving train led by the concrete paver, which averages laying approximately 2,000 cu. yds. of pavement per day. A tining machine then cuts grooves into the concrete pattern to create water displacement for better traction on the pavement. Finally, the curing machine sets up the concrete pavement for its finished appearance.

The concrete sets fairly quickly, but any vehicle weighing more than 14,000 lbs. is not allowed on the pavement for at least four days. The full curing cycle is seven days after which the pavement can be opened to normal traffic.

Also included in the project is electrical work for roadway lights and conduit to be located in the concrete median barrier. That work is considered the fifth of the project's five phases although installation of the lights will be completed in the future. The only lights installed as part of the current project will be operational at three bridges and the 14 on- and off-ramps on either side of the roadway.

"The finished project will have two lanes in each direction," Littlefield said. "But to accommodate future use as a six-lane facility, the entire outside shoulder is paved to a width of 12 ft. rather than the conventional 10-ft. width. That way, when we expand, that third lane will also be in place. All we'll have to do is remove the concrete median and build the 10-ft. shoulders."

Littlefield estimated that the six-lane configuration could be installed as soon as five years after the completion of the reconstruction project. "It could be as little as five or as much as 10 years," he said. "Either way, we'll be ready."