Highways 281 and 337 are two major thoroughfares that run in and out of Mineral Falls in Palo Pinto County, TX. After several years of increased growth, traffic in the community has grown enormously causing pavement deterioration on both highways. With high temperatures around 97°F, low temperatures around 32°F, and average precipitation of 29.3” the harsh environment has reaped havoc on the flexible pavements.
TXDOT has a long track record of using fabrics along with a tack coat as an interlayer for overlay applications.
The two lanes on Highway 281 covers 12.6 miles and the two lanes on Highway 337 cover 11.3 miles are the limits of this project. The design engineer chose to use Mirafi.
The Design
MPV 500 along with a tack coat was chosen for the project mainly to create a waterproof membrane and help to reduce reflective cracking within the pavement system. Creating a waterproof membrane and reducing reflective cracking would prevent water from infiltrating the pavement system and sabotaging or softening the foundation of the pavement. Secondly, Mirafiｮ MPV500 was chosen by the design engineer to increase the resistance against fatigue cracking.
Mirafi MPV500 is a non-woven polypropylene geotextile with an excellent absorbency designed for asphalt overlay applications.
Before construction, the highways varied from slight to severe pavement distress. Construction began by removing and replacing components in areas of severe pavement distress and a leveling course was utilized in areas with irregular pavement surfaces. PG 64 -22 is an asphalt tack coat applied at the rate of 0.20 gal/yd2 using a distributor truck. The temperatures of the tack coat stayed above 325ｰF. Mirafi MPV500 was immediately applied using a bar rig on the front of the truck. The fabric was aligned and smoothed using push broom brushes. Then, a 2・ TXDOT Type D hot mix asphalt overlay was placed on the paving fabric.
Performance
The installation of the fabric and overlay was completed in a timely manner. They expect this system will perform up to and beyond their expectations. The sections will be closely monitored for performance for possible future applications of the system.
