Mesocrystalline calcium silicate hydrate: a bioinspired route towards elastic concrete materials.

Calcium silicate hydrate (C-S-H) is the binder in concrete, the most utilized synthetic material in the world. The main weakness of concrete is the lack of elasticity and poor flexural strength considerably limiting its potential making reinforcing steel constructions necessary. Although the properties of C-S-H could be significantly improved in organic hybrids, the full potential of this approach could not be reached because of the random C-S-H nanoplatelet structure. Taking inspiration from a sea urchin spine with highly-ordered nanoparticles in the biomineral mesocrystal, we report a bio-inspired route towards a C-S-H mesocrystal with highly aligned C-S-H nanoplatelets interspaced with a polymeric binder. A material with a bending strength similar to Nacre is obtained outperforming all C-S-H based materials known to date. This strategy could greatly benefit to future construction processes as fracture toughness and elasticity of brittle cementitious materials can be largely enhanced on the nanoscale.

Author: A. Picker, L. Nicoleau, Z. Burghard, J. Bill, I. Zlotnikov, C. Labbez, A. Nonat, H. Coelfen

Section: New materials

Keywords: concrete, calcium silicate hydrate, elasticity, flexural strength, mesocrystal, highly-ordered nanoparticles, polymeric binder.