Strain-sensing carbon nanotube cement-based composites for applications in structural health monitoring: Preparation and modelling issues

Abstract

The authors have recently explored the use of electrically conductive cement-based composites doped with carbon nanotubes for dynamic monitoring of strain in concrete structures. While the technology appears to be very promising for cost-effective structural health monitoring, some challenges still limit its applicability to full-scale constructions. The dispersion of the nanoparticles, typically based on sonic treatment and on other special procedures, is not compatible with distributed full-scale deployments and essentially limits the applications of the technology to the fabrication of embeddable sensors. Also, the electromechanical behaviour of the composites is complex and a proper analytical model linking electrical output to accurate strain measurements is yet to be established. This work discusses these open issues in fabrication and modelling of carbon nanotube composite concrete. A fabrication procedure with potential applicability to large casting volumes is presented and experimental results highlighting its effectiveness are discussed. Results cover analysis of nanoparticles dispersion, electrical percolation, strain sensitivity and polarization.