Developing a sustainable concrete substitute — ScienceDaily

Worcester Polytechnic Institute (WPI) researchers Nima Rahbar and Suzanne Scarlata have received $692,386 from the National Science Foundation (NSF) to improve and develop new functions for their Enzymatic Building Material (ECM), a “living” building material ” low-cost negative emission. they set out to address one of the biggest contributors to climate change — concrete — by offering what they refer to as “a path to repair or even replace [traditional] concrete in the future.” Rahbar and Scarlata have already made their research available for commercial use through a start-up called Enzymatic, Inc.; this new funding will also allow them to:

  • explore new avenues for the use of ECM, including the repair of cracks in various types of glass, such as eyeglass lenses, cell phone screens, and car windshields.
  • develop a program to educate diverse populations of underprivileged girls — in Worcester and in Africa — about engineering and construction.

About ECM – the need, the science and the process

According to Statisa, between 1995 and 2020 worldwide cement production jumped from 1.39 billion to 4.1 billion tons, making it the second most used substance on Earth after water. In addition to their efforts to help mitigate the massive climate change impacts created by concrete, Rahbar and Scarlata plan to use the new funding to refine and optimize ECM and the processes to create it, and expand the use of him in different materials.

Biological enzymes are catalysts that promote chemical reactions. The ECM is made through a process involving an enzyme known as carbonic anhydrase—found in all living cells—that has the unique ability to react with CO2 to rapidly remove greenhouse gas from the atmosphere. This reaction creates calcium carbonate crystals, which serve as the main component of the ECM. A sand slurry is also added, as well as a polymer, which holds the ECM together during its early stages, much like scaffolding during the construction of a building. Through this process, the ECM can “heal itself” and repair cracks or other imperfections that may develop over time, maintaining its strength for up to six self-healing cycles.

Through extensive testing and experimentation, the research team found that ECM has “tremendous” compressive strength, rivaling traditional mortar, making it strong enough to be used in building construction as compression elements. It also does not require baking at high temperatures like a traditional brick and can be made quickly, unlike the 28 days needed to cure concrete. ECM can also be produced at a low cost since the percentage of enzymes is minimal. This new NSF funding will help the team improve processes that will allow EMC to move more quickly from the lab to construction sites.

A new route for the material can also be used to repair cracked or broken glass. Scarlata says inspiration came to her through something many parents can relate to — her kids accidentally dropping and breaking cellphone screens — making her want to find a way to repair, rather than replace, glass phone screens. While Scarlata and Rahbar do not yet have data on ECM’s ability to repair glass, they believe it is possible. “This method of glass repair would save a lot of time, energy and waste,” says Scarlata. Rahbar adds, “it’s a dream now, but that science evolves … through dreams.”

What it means for girls and why it matters to the construction industry

In addition, the grant will allow Rahbar and Scarlata to develop a program based on their lab work at ECM to educate and inspire underrepresented and underprivileged girls about engineering and construction, an industry where the gender gap is wide; According to OSHA, only 9 percent of construction workers in this country are women.

The researchers plan to partner with organizations in Worcester, including the local chapter of Girls Inc. to create summer and after-school programs in which girls will design a six-inch model building, make a mold for it using 3D printing, and build structures out of ECM. Rahbar and Scarlata are also collaborating with the African University of Science and Technology to host visiting graduate students at WPI and conduct additional summer programs for this group. “Construction has traditionally been a male field and has been overlooked by young women as a possible career, but women have a lot to contribute, in all fields, including construction,” said Scarlata.

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Materials provided by Worcester Polytechnic Institute. Original written by Jack Levy. Note: Content may be edited for style and length.

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