The Utah Department of Transportation (UDOT) selected expanded shale, clay and slate (ESCS) lightweight chip seal aggregate for two sections of interstate during the summer of 2020 as well as various other locations around the state. The interstate projects were on I-80 passing Coalville, UT between Wanship and Echo Junction and the other on I-84 between Echo Junction and Henefer, UT. Together these projects totaled approximately 20 miles in length and used a total of just over 10,000 cubic yards of lightweight type C/type II chips.
Representatives from UDOT reported that the projects turned out extremely well and there wasn’t a single claim or even a complaint of a broken windshield or vehicle damage which is unheard of when chip sealing a section of interstate. There were also no areas where chips peeled off the road or became dislodged even after a year’s time and a season of snow plowing which occurs frequently during winter months in the region. No broken windshields and a superior bond with the emulsion are two of the primary benefits of using ESCS lightweight aggregates in chip seal applications. Another benefit is the excellent freeze thaw durability in cold weather climates such as Utah.
UDOT consistently uses ESCS lightweight chip seal aggregate for these reasons as well as the cost savings generated by the long-lasting pavement preservation they provide and have done so for approximately 30 years.