BY DAN HILDEBRAN
Telegraph Staff Writer
STARKE— The Florida Department of Transportation opened its concrete test road eight miles north of Lawtey on Tuesday, March 14.
FDOT said the two northbound lanes from Highland to Clay Hill parallel to U.S. 301 is the only full-scale concrete test facility of its type in the southeastern United States.
Motorists driving from Lawtey toward Baldwin are now diverted from U.S. 301’s northbound lanes to the right onto the concrete surface just after entering Clay County and are then directed back onto 301 north of County Road 218.
The 2.5-mile pavement includes 52 experimental pavement sections and a weigh-in-motion system located at the southern end to document the vehicle types and weights traveling the test road.
FDOT said it will conduct three experiments on the concrete pavement while motorists travel over the surface: structural, drainage and calibration.
“The structural experiment consists of 20 test sections,” the state agency said. “The primary purpose of these sections is to investigate different concrete thicknesses and base types. The concrete thickness ranges from 6 to 10 inches and five different base configurations are utilized. In addition, the use of reclaimed asphalt pavement as an aggregate source for the concrete pavement is part of the study.”
FDOT said the drainage experiment includes 16 test sections, some with and some without edge drains.
“The primary purpose of this experiment is to study the effectiveness of edge drains,” the agency said. “Concrete pavement joints remain unsealed in selected sections to study the effect of water infiltration through joints. Two concrete pavement thicknesses and three base types were constructed in these test sections.”
FDOT said the calibration experiment consists of 16 test sections and will be used to calibrate fatigue cracking.
“Concrete pavement joints will be sawed at two different lengths and curing application rates will be modified to ensure crack initiation at different ages.” the agency said.
In addition to the structural, drainage and calibration experiments, three different surface textures were applied to the passing lane to evaluate the effect on pavement friction, surface drainage, and pavement-tire noise.
“These surface textures include longitudinal diamond grinding, a combination of longitudinal diamond grinding and transverse grooving, and a new longitudinal diamond grinding technique known as the Next Generation Concrete Surface,” FDOT said. “Longitudinal diamond grinding, the standard surface texturing method on FDOT concrete pavements, will be performed on the entire travel lane.”
FDOT began the project in 2016 and initially scheduled completion in late 2020.
The agency added that it selected the U.S. 301 site in Clay County for the test road because of the large volume of trucks traveling the highway between Ocala and Baldwin and the absence of driveways and side streets in the Highland-Clay Hill area.
“In addition, the site is less than 40 miles from the State Materials Office (in Gainesville),” the agency said. The State Materials Office is managing the test road.
