I have seen broken glass (± 1" (~25 mm) square pieces) used effectively as the drainage backfill around a residential foundation. The owner reported that it worked very well.
An internet search shows other situations where the crushed glass is used as aggregate in construction, including some cases where the aesthetics are used to an advantage. See HowToPedia article, for example, which suggests the following uses:
Crush to sand size which removes sharp edges:
- use as bedding in place of sand
- use as aggregate instead of sand
- add to plaster for decorative shine
Crush to pebble size which removes sharp edges, use as decoration in concrete plaster.
For more, see Studies of Glass in Construction Applications, (CWC, Ref BP-GL4-01-01, Nov 96) which refers to the following (relatively old, now) studies:
Clean Washington Center ... glass as a construction aggregate.
Florida Institute of Technology ... Waste Glass and Waste-to-Energy Bottom Ash as Highway Fill Materials
Schmucker, Bruce O., and Buffalini, Rick J: Pulverized Glass and Landfill Liner Systems
University of Missouri - Rolla; Glasphalt Paving Handbook