Glasphalt, a type of
asphalt with tiny bits (4.75 mm for the surface, though larger grains can be used for base) of ground glass mixed in, is a
novel way of
recycling glass and improving the condition of paved surfaces. It was originally developed as a way of recycling mixed-color glass or "cullet," which cannot be melted and recycled into bottles.
It has several benefits over ordinary asphalt, including increased resistance to skidding and quicker drying after a heavy rain. In addition, it makes road surfaces shiny, reflecting streetlights for easier nighttime driving.
Glasphalt has been used on streets and highways for many years in the Baltimore area, though it was eventually discontinued because of high cost. Recently, it has gained popularity, spreading to other cities. Aside from its performance benefits, glasphalt just looks better than regular asphalt.
Faculty at the University of Missouri-Rolla have been active in the research and development of this product since the early 1970's. In 1996, the Rolla airport became the first airport in the U.S. to be paved with glasphalt.
In 1995, Columbia University civil engineering professor Christian Meyer invented a glass-containing concrete mixture "glascrete" to utilize New York's additional glass waste that was not going into glasphalt.