Scientists’ work with elements at the atomic level continues to yield promising concrete admixtures whose impact might one day approach that of polycarboxylate superplasticizers. As Concrete Products has observed in reports on Zenyatta Ventures Ltd. and EdenCrete Industries this past year, nanotechnology has led to identification and processing of concrete market-ready graphene, a single atom-thick layer of pure carbon derived from mineral or synthetic graphite.
Among newer companies formulating concrete admixtures through nanotechnology is Australia-based NanoGraphene Inc., whose material imparts crack resistance plus improved strength and ductility in finished slabs or structures. Company officials describe graphene as a “allotrope of carbon … strong, flexible and a good conductor of electricity … 200 times stronger than steel.” The latter property makes graphene admixtures ideal for concrete structures requiring very high tensile strength and superior mechanical properties.
NanoGraphene arrives in concrete following EdenCrete Industries and Zenyatta Ventures, each armed with technology capable of tapping carbon atoms’ potential to improve the properties of cast-in-place or precast concrete. Littleton, Colo.-based EdenCrete, the North American subsidiary of Eden Innovations Ltd., Australia, offers a namesake liquid admixture dosed at up to 4 gal./yd. and bearing quintillions (one million trillion) of carbon fiber-like tubes, or carbon nanotubes.
Eden Innovations scientists present carbon nanotubes as cylindrical structures comprising bundles of graphene having single-atom wall thickness. By bonding to hydrating cement particles, the 99.5 percent (or higher) pure carbon structures create millions of strong, flexible bridges throughout a concrete matrix, while also improving cement paste–aggregate bonds. Neutral and non-reactive, the EdenCrete agent can be used with standard chemical admixtures, and does not hamper mix workability and finishability. Compared to a plain or conventionally reinforced slab or structure, EdenCrete concrete exhibits lower permeability, up to 54 percent as measured by bulk electrical resistivity; greater resistance to shrinkage, 39 percent less in ASTM C157 results; increased flexural, tensile and compressive strengths, 32 percent, 46 percent and 41 percent, respectively, higher in ASTM C78, C496 and C39 results; and, increased abrasion resistance, 59 percent greater in ASTM C779 results.
EdenCrete Industries generates its signature product through Pyrolysis, a proprietary process separating the carbon and hydrogen of methane (CH4). By contrast, Zenyatta Ventures is developing a graphene admixture derived from volcanic graphite mined at the Albany deposit near its Thunder Bay, Ontario, headquarters. The company has aligned with Larisplast Ltd. of Israel for a second phase of graphene testing toward a commercial product. From there, an agreement between the companies could spawn a partnership to market a specialized admixture product globally.
Working with Ben-Gurion University of the Negev, Larisplast has converted graphite from Ontario to a graphene admixture with an eye to testing it for a variety of quality control factors and mixture dispersion properties, plus short- and long-term strength development. Concurrent with the Lariplast partnership, Zenyatta Ventures has formed a subsidiary, ZEN-tech Materials Ltd., to focus on development and commercialization activities of graphene applications, plus intellectual property allocation and worldwide technology licensing. ZEN-tech will capture value and advance graphene application development separate from the mineral development business. Zenyatta will focus on advancing the Albany deposit towards commercializing its brand of highly crystalline, purified graphite.
Foreshadowing how ZEN-tech, Larisplast, EdenCrete and its other nanotech peers might impact concrete—along with other engineering, industrial and consumer applications—NanoGraphene boldly observes, “The Age of Plastic is coming to an end before our eyes, giving way to the Graphene Age and its superior technologies.” Early commercial applications and laboratory testing suggest the concrete industry is fertile ground for individual carbon atoms.