In potentially transformative research for both the recycling and concrete industries, a City College of New York civil engineering team is developing a glass powder to replace cement in the production of concrete. The material conceptualized by Dr. Julio Davalos and doctoral student Marija Krstic, was tested for sidewalk construction in South Jamaica, Queens, by the New York City Department of Design and Construction on May 5.
It was the first such demonstration in the United States, according to Davalos, chair of civil engineering in City College’s Grove School of Engineering.
Davalos’ research with Krstic entails developing the new glass powder ingredient for concrete from post-consumer recycled color glass that has no value-added market.
“Cement is the binder in concrete, but its production emits an equal amount of CO2. Thus nanoscale materials (pozzolans) are used to partially replace cement and enhance concrete performance,” noted Krstic.
The most common pozzolan used is fly ash, a byproduct from coal burning plants. However, due to plant closures and conversions to natural gas, there is a severe shortage of fly ash, which makes this CCNY development significant.
“This innovation has potential for worldwide application and economic development,” said Davalos. Louis Grasso of Urban Mining Northeast collaborated with the CCNY team.
New York City officials test the new CCNY developed concrete glass powder for sidewalk construction in Queens. From left: Richard Jones and Jean Clermont (both NYDDC); Louis Grasso (Urban Mining Northeast); and CCNY’s Julio Davalos and Marija Krstic.