“Glascrete”—Concrete with Glass Aggregate

Abstract

Post-consumer glass represents a major component of solid waste, yet its use as an aggregate in concrete is problematic because of the strong alkali-silica reaction (ASR) between the cement paste and the glass aggregate. In a research project at Columbia University, the use of crushed waste glass as aggregate for concrete products was investigated. Fundamental aspects of ASR in concrete with glass aggregate were studied. It was shown that waste glass ground to U.S. standard sieve size No. 50 or smaller causes mortar bar expansions in the American Society for Testing and Materials C 1260 test of less than 0.1%, which is less than that of reference bars without any glass. Also, green glass does not cause any expansion to speak of, and finely ground green glass has the potential of an inexpensive ASR suppressant. Specific concrete products with glass aggregate are currently under development. These include concrete masonry blocks with 10% mixed color waste glass aggregate and glascrete products with 100% color-sorted glass aggregate for numerous architectural applications.