A Missouri University of Science and Technology research team was recently awarded $2.5 million in funding to find new ways to turn waste products into supplementary cementitious materials (SCMs) – plus use those materials to store carbon permanently in concrete.
"Years ago, SCMs were used as a cheap option to replace some Portland cement and also have a stronger and more durable concrete mixture," says Dr. Hongyan Ma, Francisco Benavides Scholar and associate professor of civil engineering at S&T. "There is now a severe shortage of these materials, so my team is looking at creative ways to develop new alternatives that are carbon-negative and will make the industry greener."
Ma also serves as director of S&T's Laboratory of Future Cements and Carbon-Negative Initiatives.
He says one of the most common SCMs has traditionally been coal combustion residue, or fly ash, but a large percentage of this type of waste is not currently usable in cement. According to the Electric Power Research Institute, 2.5 billion tons of this type of waste have been disposed of in ponds and landfills throughout the United States.
Ma's two-year research project, which received a $2 million grant from the U.S. Department of Energy and $500,000 in matching funds from S&T and industry partners, aims to make this unusable waste into something of value.
The research will also cover the ash from municipal solid waste incinerators, steel slag, recycled concrete and other waste products. The team is currently developing processes to break down the structure of the solid wastes in ways that will also allow them to store CO2.
The carbon that is combined with these new SCMs will primarily come from the flue gases of power plants and the manufacturing industry, Ma says. By using CO2 directly from the flue gasses, as long as the concentration is high enough, his team will not have to use energy-intensive carbon-capture methods.
Ma says this project is designed to make a significant difference in the concrete industry in the near future, as opposed to focusing on more general, long-term concepts.
"The work we are conducting is mission-oriented," he says. "Part of our research is to make sure what we develop is economically feasible. It can't be too expensive, as it needs to be a realistic option to support the supply chain."
Ma is the project's principal investigator (PI). Serving as his co-PIs at Missouri S&T are: Dr. Aditya Kumar, associate professor of materials science and engineering; Dr. Mahelet Fikru, associate professor of economics; and Dr. Wenyu Liao, assistant research professor of civil engineering. Lawrence Livermore National Laboratory is also collaborating with S&T for the project.
Source: https://www.mst.edu/