Austin Public Works Department Uses Glass Crusher to Make Artificial Sand and Gravel
The Austin (Texas) Department of Public Works installs a new concrete sidewalk on top of a two-inch layer of fine grained glass made of waste diverted from its landfill. At $5 to $6 per ton, the re-purposed glass can compete in price with natural aggregate.
A glass crusher makes glass cullet out of waste glass at a Materials Recovery Facility (MRF) in Austin, Texas. The crusher can output cullet in various consistencies, as course as pebbles or as fine as sand. It can then be used as landscape mulch for walking trails, drainage media for pervious pavements, backfill for a retaining wall, or bedding material under sidewalks and small diameter water and service lines.
Cullet that is clean and sorted by color can fetch as much as $60 per ton in some markets, but unsorted glass co-mingled with other waste is virtually worthless to manufacturers. However, it can bring $6 per ton as an aggregate substitute for roadbeds and other projects.
Keri Burchard-Juarez, P.E., PMP is the Assistant Director for Engineering and Capital Project Delivery for the City of Austin Public Works Department.
Steven J. Penshorn, P.E., CPM, is a Supervising Engineer for Quality and Standards Management in the City of Austin Public Works Department.