Innovative nano reinforced restoration materials: Design at the nanoscale, piezoresistive evaluation at the microscale and their sustainability

Abstract

In the present article, the holistic concept of designing reinforcement at the nanoscale for lime-based restoration materials up to the sustainability aspects of the restoration with innovative materials is assessed. Within the framework of research project “Advanced Cultural Heritage”, the University of the Aegean was the responsible partner to perform the design at the nanoscale, i.e., to perform an investigation on the appropriate process parameters to uniformly disperse the carbon-based nanostructures (CBNs) on aqueous solution. The type, concentration, and dispersion capability of the CBNs are critical to the restoration material, since they are responsible to enhance the material with another functionality (piezo-resistivity) that enables for remote structural health monitoring of the restored area. As a working example, it was shown that the addition of 0.15 wt% multi-wall carbon nanotubes (MWCNTs), increases by 25 % the compression strength of the ternary binder as well as the binder was enabled with piezo-resistive characteristics. An approximate 22 % normalized electrical resistance change under compression loading – unloading loops at loading level of 50 % compressive strength was noticed. The economic viability and sustainability of the new technology was demonstrated for a 25 years’ service life, where the innovative restoration approach with the exploitation of nano reinforced material, proved to cost less for maintenance and monitoring activities over the designated time span.