Grand Canyon North Rim
Dec 10, 2013
Budget constraints limit how often a road gets paved in our National Parks. The parks are often located in remote enviornments, far from a local asphalt mix plant. Then, in the summer, tourists swarm the parks and their roadways. Considering these factors, the Office of Federal Lands Highway requires reliable, high-performing paving operations outside of the traditional paving months.
Trucks loaded with Evotherm WMA from Western Rock Products in Kanab, UT, headed for the North Rim of the Grand Canyon. They travelled over two hours to Cape Royal Road where a paving train awaited the start of the overlay project. The National Park Service specified the construction of the overlay using an Ultrathin Bonded Wearing Course. This overlay technique utilizes a spray paver, one designed with an integrated emulsion spray system that applies the emulsion directly in front of the wave of asphalt mix under the paver machine. Evotherm was chosen by Western Rock Products to address the long haul and cool ambient conditions.
While the temperatures hovered in the upper 50’s, the strong winds along the canyon rim quickly cooled the thin lift of asphalt mix. Mix temperatures behind the screed hovered near 240°F with minimal clumping. A visiting engineer was concerned about conducting the job due to the cold temperatures, windy conditions, and long haul distance. After arriving onsite, he was even more confused to observe the mat looking so good. Having been involved with the Golden Gate Recreational Area, he quickly understood how the job was progressing so well when he learned that the mix contained Evotherm technology. Both the National Park Service and Western Rock Products were pleased with the quality of the finished surface and identified Evotherm as a key component to their success.
Author: Brandon Milar