Dr. Francis Dube reports
GRAPHENE DERIVED FROM ALBANY GRAPHITE CONTINUES TO SHOW CONSIDERABLE PROMISE AS CEMENT ADDITIVE
Zenyatta Ventures Ltd. has released preliminary research findings from University of Toronto that point to significant improvements in the compressive and flexural strength of cement when graphene products derived from Albany graphite are combined with the cement.
Including graphene in quantities of as little as 0.02 per cent increased the compressive strength of cured cement paste by up to 39 per cent, according to research conducted by professor Daman Panesar and her team at University of Toronto's department of civil and mineral engineering, where she is one of the inaugural recipients of the Erwin Edward Hart Professorship in Civil Engineering. A broad objective of professor Panesar's research is to advance concrete technologies by investigating new types of concrete to reduce environmental impact, improve economic feasibility, achieve desired plastic and mechanical properties, and improve long-term durability performance. Although still at a preliminary stage, professor Panesar's work confirms and builds upon research that was previously conducted at Ben-Gurion University in Israel by professor Oren Regev and his team.
"These encouraging preliminary results strengthen the business case for using graphene in concrete," said Dr. Francis Dube, Zenyatta's co-chief executive officer and head of business development. "With such a low graphene loading, Zenyatta may now be able to pursue the ready-mix concrete market, which is much larger than the significantly smaller volume ultrahigh performance concrete market." The ready-mix concrete market is estimated at $500-billion (U.S.) per year.
For the current round of research, three forms of Graphene-based materials -- graphene, graphene oxide and reduced graphene oxide -- were systematically tested. The three types of graphene material were mixed with cement in a range of concentrations, from 0.01 per cent to 0.16 per cent of the cement weight, and the results compared to a control specimen comprised 100 per cent Portland cement paste (without graphene).
Adding any of the three graphene materials improved both the compressive and flexural strength at three, 14 and 28 days, by varying degrees. At the 28-day mark, the inclusion of graphene materials improved compressive and flexural strength by a maximum of 39 per cent (for 0.02 per cent graphene) and 84 per cent (for 0.04 per cent reduced graphene oxide), respectively, compared with the control cement paste. Furthermore, all three forms of graphene materials improved the cement paste's transport properties at 28 days. (Transport properties are related to the porosity of the resulting composite: the lower the porosity the better, as it reduces fluid flow through the material and potentially results in a higher durability.) The microstructural analysis and transport properties of 28-day-old graphene-cement composites showed that the presence of graphene materials densified the composite microstructure.
The dispersion of the graphene is a key factor in achieving these results, and graphene derived from Zenyatta's unique Albany graphite deposit has particularly good dispersion qualities. Previous research by professor Yoshihiko Arao and professor Masatoshi Kubouchi at Japan's Tokyo Institute of Technology concluded, "The optical absorbance of the Zenyatta graphene was two to 10 times better than the other three tested reference samples which demonstrate concentrated graphene dispersion."
Zenyatta will continue to work with professor Panesar and her team as they study in greater depth graphene-infused cement-based composites, including graphene dispersion techniques, repeatability of results, the long-term properties of graphene-cement composites as well as their performance in more complex cement-based systems such as mortar and concrete.
Professor Panesar's research was supported by financing from the government of Canada through the NSERC Engage funding program. Zenyatta also acknowledges the contributions of professor Aicheng Chen at University of Guelph who provided the graphene oxide and reduced graphene oxide for professor Panesar's research, and professor Giovanni Fanchini at Western University who provided the graphene -- which were all produced from graphite samples provided by Zenyatta from its Albany deposit.
Peter Wood, PEng, PGeo, vice-president of Zenyatta, is the qualified person for the purposes of National Instrument 43-101 and has reviewed, prepared and supervised the preparation of the technical information contained in this news release.
About Zenyatta Ventures Ltd.
Zenyatta's Albany graphite project hosts a large and unique quality deposit of highly crystalline graphite. The deposit is located in Northern Ontario just 30 kilometres north of the Trans-Canada Highway, near the communities of Constance Lake First Nation and Hearst. Important nearby infrastructure includes hydro power, natural gas pipeline, a rail line 50 kilometres away and an all-weather road just 10 kilometres from the deposit.
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