While attempting to create more environmentally friendly cement products, CTS Cement Manufacturing Corporation, a manufacturer of specialty fast-setting hydraulic cement and shrinkage compensating cement, has discovered new structures in mixtures of coal flyash and hydrated calcium sulfoaluminate cement.
Self-organising structures
The structures consist of micron-sized glass spheres upon which needles have grown radially. Whereas these needles usually grow randomly in the company’s Rapid Set® cement, in flyash/cement mixes they organise themselves as spines on round flyash particles. They are very small, typically a few tens of microns in size, and can only clearly be seen under an electron microscope.
According to Dr. Eric Bescher, Vice President for Cement Technology at CTS Cement, this is the first time these complex structures have been seen.
Strength benefits
“Think of these structures as micron-sized sea urchins shells embedded in cement paste,” said Bescher. “We have some indications that they may play a beneficial role in the reinforcement of concrete or in shrinkage mediation. Our work is in progress and we are investigating the influence they could have on other properties of construction materials.”
New discovery
CTS Cement believes that this is a new discovery. The company thinks it may be possible that these structures grow and develop only in calcium sulfoaluminate cement/flyash mixtures.
The discovery was made when substituting some of the Rapid Set cement with an alternative raw material: flyash. The aim of this is to reduce the product’s carbon footprint; it may be that the new discovery can offer even greater benefits.
BescherBalls
The structures have been named BescherBalls and CTS Cement is undertaking further investigations to understand what part they might be able to play in future construction materials.
“We have much more to learn about this ingenious design and the formation mechanism of these structures,” says Bescher. “Our research teams are hard at work.”
Adapted from press release by Katherine Markham
Read the article online at: https://www.worldcement.com/the-americas/13042012/flyash_mix_shows_potential/
