The concrete problem

Mohammed Teymouri, assistant professor of construction management in South Dakota State University's Jerome J. Lohr College of Engineering, is working to solve one of the most pressing issues in the construction industry: how to lower carbon emissions of concrete. 

Concrete is the world's second most widely used material after water and is crucial to construction projects around the world. Concrete is also responsible for 8% of the world's total carbon emissions. 

As the world moves toward a "net-zero" carbon future, one of the biggest challenges will be reducing and eliminating concrete’s carbon emissions. This will be especially difficult as the need for and use of concrete — the primary material for the world's bridges, roads, dams and other infrastructure — is only expected to rise.

Mohammed Teymouri is an assistant professor of construction management in South Dakota State University's Jerome J. Lohr College of Engineering. His research is focused on solving the concrete emissions issue by developing low-carbon concrete mixtures.

"We are playing with the ingredients of concrete," Teymouri said. "We want to make a combination that is not only strong performance wise, but also environmentally friendly." 

Concrete is made by mixing a binding mass, either conventional cement or modern binders, with aggregates like stone, gravel or sand, and water. The environmental issue lies in cement production, which is extremely carbon intensive. 

"Portland cement" is the most popular type of cement used in construction. During its production, the limestone used undergoes a calcination process that releases large amount of carbon into the environment. This process is primarily responsible for concrete's carbon emissions, and the concrete industry as a whole is looking to achieving net-zero carbon emissions by 2050. 

To "fix" the concrete emissions issue, researchers must first start with the carbon-intensive cement production process. Previously, Teymouri has conducted research on alkali-activated concrete, or cement-free concrete, as it is otherwise known. Alkali-activated concrete is a cementitious material that can be used as a substitute for Portland cement concrete. It is estimated that widespread use could significantly reduce carbon emissions.

But as Teymouri explains, there is not just one approach that will work in reducing carbon emissions for the concrete industry. Different countries, or even different parts of countries, will take different approaches. The end goal will be the same: low-carbon concrete. How each country gets there will be different and will be reliant on the materials most accessible to them. 

As a new faculty member in the Lohr College, Teymouri's research program is just getting started, but he is excited to find collaborative opportunities with other researchers on campus. He came to SDSU after earning his doctorate in civil and environmental engineering from Colorado State University. 

In the immediate future, Teymouri will continue his work on the impacts of chemical admixtures and its effects on the short-term and long-term properties of concrete made from new commercially available cement (Type IL Cement). The research is supported by a grant from the Portland Cement Association.