The Utah Department of Transportation (UDOT) used Expanded Shale Lightweight Aggregate to chip seal a portion of Interstate 84 between Echo Jct. and Henefer, Utah in the summer of 2012.
This section of I-84 is located only 50 miles from Salt Lake City and 36 miles from Ogden, and receives continual heavy truck traffic as well as frequent snowplowing during 5 months of the year. New pavement was required on this stretch of roadway in 2012. Rather than leaving the new pavement exposed, UDOT chose to have a chip seal placed over it to pro-long its life by protecting the new pavement from weathering and traffic.
Although chip sealing is the most economical way to maintain an asphalt surface, many state DOT’s have gotten away from chip sealing interstate highways because of chips peeling or stripping off of the road, and because of complaints arising from broken windshields.
UDOT’s Type III “crusher processed rotary kiln lightweight expanded shale chips” were chosen for the project because they do not break windshields and do not peel or strip after being applied. This is because UTELITE lightweight aggregates are porous and do not contain clay or silica dust that prevents a firm bond with the emulsion. An adjoining section of Interstate 80 from Echo Jct. to Coalville was chipped with UTELITE chip seal aggregate in 2004 and again in 2010 after 6 years of service on a very busy section of freeway.