In 2024, Arizona used foam made from 100% recycled glass at 19 sites while...

I-17 Improvement Project using foam glass aggregate as a new innovative construction material Engineers in Arizona have used an unusual material to expand a major interstate: tens of thousands of tonnes of crushed recycled glass. During the expansion of Interstate 17 north of Phoenix, construction crews used ultra-lightweight foam glass aggregate at 19 locations along a 23-mile section. The material, made entirely from recycled glass, provided a lightweight structural fill that allowed existing drainage culverts, built decades ago for a two-lane highway, to support extra traffic lanes without being crushed by the added weight. According to the Arizona Department of Transportation (ADOT), this was the first time foam glass aggregate had been used in a state infrastructure project. In an official agency publication, ADOT Communications representative Laura Douglas said the material was chosen because it combines high compressive strength, low weight and environmental benefits.Solving structural challenges on a busy corridorThe 23-mile section of Interstate 17 between Anthem Way and Sunset Point is one of the region's busiest major routes, carrying more than one million motorists each...