Implementation of bio-inspired organic/inorganic layer structures as interphase in carbon fiber reinforced concrete

Materials & Design, vol. 243, pp. 113034

Abstract

Biological materials found in nacre or glass sponges reveal specific layered organic and inorganic structures known for their fracture toughness caused by crack deflection and −bridging. This work aims to bio-mimic the brick-and-mortar (BnM) structure from nacre and the layer-by-layer (LbL) structure from the glass sponge filaments to incorporate these effects into the contact zone of carbon fiber-reinforced concrete (CFRC) in order to prevent brittle composite failure. To build up BnM- and LbL-structure materials such as nanoclays, sodium water–glass and polymer dispersions were selected since they are well-established low-cost materials in building. Nanoclays were analyzed regarding their size, dispersibility and exfoliation. Montmorillonite (MMT) was used to be mixed with polymers to produce self-assembled BnM-structured films and coatings. Also, LbL structures were formed by alternating layers of sodium water glass and polymer. Scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to verify the morphology. The MMT-containing coatings demonstrated enhanced nucleation potential when exposed to cementitious eluate. Micromechanical pull-out tests on single carbon fibers with BnM- and LbL-coatings embedded in concrete demonstrate the potential to increase composite toughness. The successful implementation of the bio-inspired structures using affordable materials lays the groundwork for their scalability and integration into composite structures for building.

Authors 4

1. Toni Utech

   Leibniz Institute of Polymer Research

   Affiliation as printed

   Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany

2. Henning Kruppa Aachen Chair of Building Materials Institute of Building Materials Research

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Chair of Building Materials and Institute of Building Materials Research, Schinkelstr. 3, 52062 Aachen, Germany

3. Anya Vollpracht Aachen Chair of Building Materials Institute of Building Materials Research

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Chair of Building Materials and Institute of Building Materials Research, Schinkelstr. 3, 52062 Aachen, Germany

4. Christina Scheffler corresponding

   Leibniz Institute of Polymer Research · Technische Universität Dresden

   Affiliation as printed

   Institute of Construction Materials, Technische Univerisität Dresden, 01187 Dresden, Germany

   Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany