Picture a section of highway being excavated, crushed into gravel-sized aggregates, and re-buried into the ground as fresh pavement. Sounds like the sort of short-term solution one would expect to decay to dust within a season, but in the mid-1980s, the state's transportation department actually did just this along a stretch of Interstate 57 near Effingham. And twenty years later, engineers returned to the site to see how well their experiment had borne up.
As per a 2009 Illinois Center for Transportation research report by Jeffrey Roesler and J. Gregory Huntley, things were going swimmingly. Between 1986 and 1987, the Illinois Department of Transportation (IDOT) excavated a four-and-a-tenth-mile stretch of an older, faulted concrete roadway, repurposing the broken-up aggregate as the primary component in a ten-inch-thick continuously reinforced concrete pavement (CRCP).
