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Thermoplastic carbon-based cements

One example of a thermoplastic carbon-based cement is C-Fix which is a carbon-based organic cement. It is produced as a waste/residue when crude oil is ´cracked´ and historically has been burnt to avoid waste-handling measures but, in so doing, contributed CO₂ to atmosphere.

C-Fix was developed by Shell and the University of Delft (NL) and needs to be heated to 200°C before being added to aggregates/fillers to make a ´carbon concrete´. It has properties in common with both asphalt and cement-based concretes but is mixed and applied using asphalt techniques. The developers claim that the carbon footprint of C-Fix concrete is 3½ times lower than that for Portland cement-based concrete (but this is only credible when the carbon footprint of the refining process that gives rise to the residue is completely discounted.)

C Fix is a thermoplastic material (it softens when heated and hardens again when cooled), and as such, within ´concrete´ it is temperature and pressure sensitive.

It may have considerable potential as a replacement for asphalt in road-surfacing work, concrete in industrial flooring/paving and use in the marine and chemically extreme environments

Further information is available in the MPa Cement Fact Sheet 12

Acknowledgement: The Concrete Society