In 1970, California tested a road surface made of recycled glass, marking an early step in sustainable infrastructure.
Glass road in Fullerton
On October 26, 1970, a road in Fullerton, California, was constructed using recycled glass as part of an environmental initiative. The project, led by researchers from the University of Missouri-Rolla for the United States Environmental Protection Agency, aimed to find a way to reuse millions of non-refundable bottles that were filling landfills.Experimental road design
The road was built in a low-traffic area within Fullerton’s industrial park. Technicians applied the glass-based mixture on three-quarters of the road’s width, while the remaining quarter used conventional asphalt as a control for comparison. This setup allowed researchers to evaluate the performance of the new material over several years.Glass processing and mix
The glass used came from non-refundable bottles, which were crushed into particles of varying sizes using a hammer mill. Rock dust and hydrated lime were added to create a homogeneous asphalt mix. The final layer was 7.5 centimeters thick, laid over a base of crushed rock and compacted only after the mixture had cooled enough to prevent cracking.Performance evaluation
Core samples taken after the road was built showed that the glass section had been compacted satisfactorily. The skid resistance of the glass surface matched that of the conventional asphalt, indicating that the recycled material performed similarly in terms of safety and durability.
