In research on hydrated calcium sulfoaluminate cement and fly ash mixtures, Rapid Set brand producer CTS Cement Manufacturing Corp. has discovered needle-like formations that grow radially and organize themselves as spines on round fly ash particles.
While Rapid Set cement specimens have exhibited random needle growth, Vice President for Cement Technology Dr. Eric Bescher notes this is the first time such complex structures—typically a few tens of microns in size that can only be seen clearly under an electron microscope—have been observed. Think of these new self-organized inorganic architectures, he explains, “as micron-sized sea urchin shells embedded in cement paste. We have some indications they may play a beneficial role in the reinforcement of concrete or in shrinkage mediation, [and] are investigating the influence they could have on other properties of construction materials.”
CTS is not aware of reports on similar structures in scientific literature to date and cites the possibility that they only develop in calcium sulfoaluminate/fly ash mixtures. The discovery stems from attempts to make the already green Rapid Set product even greener, notes Bescher, adding, “By substituting some of the Rapid Set cement with fly ash, we will further reduce the already minimal carbon footprint of [our] cement while finding a use for a waste material. In this process, we stumbled onto something unexpected, the significance of which is to be determined.”
The producer continues investigation of the so-called, self-organized BescherBalls—a working name for the microstructures. “We have much more to learn about this ingenious design and the formation mechanism,” says Bescher. “Our research teams are hard at work.” — CTS Cement, Cypress, Calif., www.ctscement.com
Eric P. Bescher is Vice President for Cement Technology and has worked with CTS Cement since 1997. He holds a master’s degree and doctorate in materials science from the University of California Los Angeles. As Associate Adjunct Professor at UCLA, he teaches undergraduate and graduate Materials Science, and focuses advanced cementitious materials fundamentals.