Carbon nanostructures incorporated to C3S- and cement-based binders

Carbon Nanotubes (CNTs) are well known for their unparalleled mechanical properties. Additionally their very high aspect ratio and low specific weight make them a very promising reinforcement material for composites. Recently carbon nanotubes were incorporated to plain cement pastes and normal concretes, ultra-high performance concretes and C3S-model systems leading to improved mechanical properties. Also different carbon nanostructures like multi-walled carbon nanotubes (MWNTs) and carbon nano-coils (CNCs) were used and their influence on the hydration of C3S and the mechanical properties of the composite were examined. In situ x-ray powder diffraction (XRPD) and differential heat-flow calorimetry (DCA) were used to get information about how the nanostructures influence the hydration. Also their effect on the microstructure had been observed. The results show that the carbon nanostructures (CNSs) influence the hydration as well as the microstructure and are leading to improved mechanical properties of the composite. In this work we dispersed MWNTs by sonification and the use of sodium dodecyl sulfate (SDS) and incorporated them into pressure compacted prisms. The influence of the SDS and the MWNTs on the hydration, microstructure and the mechanical properties were examined.

Author: T. Kowald, S. Eser, R. Trettin

Section: Science and production

Keywords: nanocomposite, multi-wall nanotube, structural analysis, sample preparation, reaction kinetics, microstructure, mechanical properties