An insufficient fire resistance of the composite material has so far inhibited a broad application of carbon-reinforced concrete. The reinforcement elements available at present are composite materials made of carbon fibers with a high number of filaments, which are embedded in a polymer matrix. The polymeric impregnation materials ensure the bond between the individual filaments and the concrete matrix. However, the inserted polymers soften under the effect of heat, and the carbon-reinforced concrete can no long resist the acting mechanical loads.
A promising approach is the development of less temperature-sensitive impregnation materials on the basis of mineral finest materials, however, this involves a lot of challenges. For one thing, the physical interaction of the hydrophobic carbon fibers with the water-based suspensions has to be increased and, for another thing, it is very difficult for the particle suspensions to penetrate the carbon multi-filament yarns.
In current studies, the development of such mineral-based impregnation materials is pushed forward, with their effectiveness being verified. In this process, it was already possible to demonstrate that the particle sizes of the reactive finest materials have a remarkable influence on the mechanical performance of the coated reinforcement elements, which consequently is also expressed in the bond behavior of the carbon-reinforced concrete. Additionally, it was demonstrated that a purposeful plasma treatment of the carbon fibers can considerably improve the interaction with the suspension of mineral finest materials.