Autonomous Application of Smart Cement Sensor-repairs

Self-sensing cements offer a unique opportunity to unify our approach to the remote monitoring and maintenance of concrete assets. The objective of this work is to develop a remotely-deployable, “smart cement” technology that can simultaneously repair damage, monitor underlying structural strain and attempt to detect further defects. Automating the deployment of these materials using robotics will improve the efficiency of installation and permit application to areas with restricted access or hazardous environments. Here, we present our latest progress in manufacturing and robotically spraycoating smart cement sensor-repairs onto concrete substrates. Spray-coating provides controllable, high pressure distribution of the material, providing high geometrical accuracy in addition to high adhesion. The smart cements are based on metakaolin geopolymers — a novel class of cement-like binders that cure to a strong, chemically resistant, electrically conductive shell. In this work, the manufacturing process of the geopolymer patch is presented before investigating the sensing capability. Initial results regarding the temperature and strain sensing of the patch demonstrate the dependence of measurements on the frequency of the applied potential. Furthermore, exploiting this dependence presents the possibility of self-compensating for temperature.