Making Waste Useful

By Andrew Wyder
Matt Gombeda

Finding ways to utilize fly ash is of interest to a variety of stakeholders in the United States, both from an environmental standpoint and as an attractive alternative for the concrete industry. Assistant Professor of Civil Engineering Matt Gombeda received a nearly $1 million grant in October to examine methods to incorporate fly ash in high volumes as a supplementary cementitious material (SCM) for precast concrete applications. Here’s a look at the reasons why:


Why Precast Concrete:
Precast concrete products, which are generally used in buildings and other structures in the form of prefabricated products such as concrete beams, slabs, and columns, offer high quality control and rapid fabrication and installation.

Fly Ash

Why Fly Ash:
As of 2017, power plants in the United States produced more than 38 million tons of fly ash, a fine powder coal byproduct, according to the American Coal Ash Association. The U.S. Department of Energy is interested in its potential uses for two main reasons—economic opportunities and environmental benefits.

Precast Concrete

How Does It Work:
Incorporating fly ash, which is already done at lower levels, into concrete can make creating precast concrete products more difficult, so Gombeda and his collaborators are working to develop novel concrete mix designs consisting of next-generation high-volume fly ash binders. This effort will be done by first re-engineering the binders’ hydration mechanisms, then scaling up the most effective binders to feasible concrete mix designs, and, lastly, demonstrating proof of concept via full-scale experimental testing of precast components.

Acknowledgment: “This material is based upon work supported by the Department of Energy under Award Number(s) DE-FE0031931.”

Disclaimer: “This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.”

Photos: David Ettinger