APPLICATION: The Lake Pontchartrain Causeway is one of the longest roads in the world, connecting the Mandeville area to New Orleans. Over 43,000 vehicles travel this causeway on a daily basis. The pavement condition at the beginning of the causeway had deteriorated and was in need of rehabilitation.
CHALLENGE: The pavement surface was exhibiting transverse and longitudinal cracking due to many years of heavy traffic. There was a significant amount of distress and a simple mill and fill (3”-6”) would not work because the cracking would reflect through soon after the overlay was installed. Other options such as a full depth reconstruction would require long lane closures and much higher construction costs. SITE CONDITIONS: The weather is warm and humid. Summer temperatures range from 80-90°F and can drop below freezing during winter nights. After years of exposure to the sun, the asphalt had oxidized and become quite brittle.
SOLUTION: The GlasGrid® Pavement Reinforcement System along with a slightly modified “mill and fill” approach was selected as a lower cost alternative to reconstruction. Approximately 3” of the existing pavement was milled to accommodate the 1.5” leveling course and a 1.75” overlay. GlasGrid® 8501 comes with a high quality, pressure sensitive adhesive that provides the bond to the new leveling course. This solution allowed for traffic to proceed without any delays.
PERFORMANCE: Over the last 6 years, the 1.5 mile section has performed extremely well and remains essentially crack free even through weather events. Only a few small cracks can be found in the area immediately next to the curb. The main travel section is crack free.
SYSTEM ADVANTAGES: Introduced in 1989, the GlasGrid System consists of stiff environmentally friendly fiberglass material coated with a specially formulated elastomeric polymer. The grid is rolled out over a smooth asphaltic surface, rolled with a pneumatic tired roller, and can be paved immediately with an overlay. The GlasGrid System is considered the most expedient installed interlayer system available. GlasGrid has been successfully used within asphalt overlays throughout the world to combat reflective cracking initiated by one or more of the following:
Concrete pavement longitudinal and transverse joints
Cement treated or stabilized layer shrinkage cracks