Eco-Friendly Cement Unveiled by Researchers at Western Sydney University

Concrete is essential for the construction industry, but bad for the environment. A team of researchers is working to solve this problem.

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Concrete is massively important to the construction industry. It provides a strong base for countless construction jobs, serving as the foundation for structures ranging from one-story homes to one-hundred floor skyscrapers.

Unfortunately, the production of Portland Cement, an essential ingredient in concrete, makes up 5 to 8 percent of all global greenhouse gas emissions. According to a 2016 report, if the concrete industry were a country it would count as the third-largest emitter of CO2 in the world behind only China and the United States.

In order to lessen the impact that concrete has on the global environment, researchers have been working to develop new formulas that significantly decrease the environmental impact of concrete without lessening its structural integrity. One team of researchers working out of Western Sydney University recently announced study results that they believe could eventually lead to the replacement of conventional cement.

The team has been working on developing a carbon-neutral form of cement known as MOC (magnesium oxychloride cement) since 2017. As a carbon neutral material that can actually absorb CO2 from the atmosphere, MOC is undeniably more environmentally friendly than traditional cement. It even has several properties superior to those of conventional cement, including a faster-setting formula and much higher compressive strength.

However, MOC does have a fatal flaw. It lacks resistance to water, losing strength and integrity when exposed to water and moisture. That weakness has made it practically unusable within the construction industry at large.

But last week, the researchers at Western Sydney University, led by associate professor Yixia (Sarah) Zhang, released a report stating that they have developed a formula for MOC that makes it much more water-resistant and therefore viable for use in construction applications.

“The MOC can fully retain these strengths after being soaked in water for 28 days at room temperatures,” reads the report. “Even in hot water (60˚C), the MOC can retain up to 90% of its compressive and flexural strength after 28 days.”

The team finds the idea that MOC could one day become a replacement for traditional cement “very promising”. First, they have to solve another large issue: steel corrodes when in MOC. Combining concrete and steel together to make reinforced concrete is a major application within the construction industry, so any new formula for concrete will have to be able to work with steel.

“More research is needed to demonstrate the practicability of uses of this green and high-performance cement in, for example, concrete,” reads the report.

A professor at Texas State has also been working on reducing concrete’s impact on the environment. You can read more about his research here.