Evaluation of Cementitious Paste, Mortar, and Concrete Mixes with Graphite

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CTLGroup conducted an experimental program designed to provide Superior Graphite with testing and evaluation of cementitious paste, mortar and concrete compositions that contain graphite or graphitic carbons produced by Superior Graphite.

The scope of phase I services consisted of laboratory trials with cement pastes containing four types of graphite or graphitic carbons. The study evaluated the rheological properties of the cement pastes with graphite or graphitic carbon additions.

Phase II concentrated on the development and characterization of rheological, physical and mechanical properties of mortars containing the same four types of graphite or graphitic carbons used in Phase I. Specifically, shrinkage, compressive, tensile and flexural strengths of carbon containing mortar specimens were determined. Additionally, rheological properties and air content of the fresh mortar pastes were evaluated.

Results of both Phase I and Phase II allowed for specific recommendations for Phase III in which concrete specimens were evaluated for thermal diffusivity, specific heat, thermal conductivity, compressive strength and freeze/thaw resistance. The decision was made to test and evaluate concrete compositions that contained resilient graphitic carbon only in Phase III. Rheological properties and air content of the fresh concrete pastes were evaluated.

Phase III results showing increased thermal conductivity of concrete with resilient graphitic carbon additions prompted analysis of possible applications performed in Phase IV Part 1. CTLGroup identified the five most promising applications for product launch
testing and planning:

    1. Mass concrete cooling systems
    2. Heated pavement systems
    3. Thermally conductive oil well cements
    4. Geothermal heat exchanger grouts
    5. High voltage cable infill materials

More cost analysis related information was also provided for architectural concrete. In the next and final stage of Phase IV, application specific test plans and preliminary product launch plans will be developed for the mostpromising applications. Regulatory requirements will be identified, the testing plan will be defined and the budget and schedule for product launch will be estimated.