The Status of Research on Self-Sensing Properties of CNT-Cement Based Composites and Prospective Applications to SHM

Abstract

Degradation phenomenacan affect civil structures over their lifespan. The recent advances innanotechnology and sensing allow to monitor the behaviour of a structure,assess its performance and identify damage at an early stage. Thus, maintenanceactions can be carried out in a timely manner, improving structural reliabilityand safety. Structural Health Monitoring (SHM) is traditionally performed at aglobal level, with a limited number of sensors distributed over a relativelylarge area of a structure. Thus, only major damage conditions are detectable. Densesensor networks and innovative structural neural systems, reproducing thestructure and the function of the human nervous system, may overcome thisdrawback of current SHM systems. Miniaturization and embedment are keyrequirements for successful implementation of structural neural systems. Carbonnanotubes (CNT) can play an attractive role in the development of embeddedsensors and smart structural materials, since they provide to traditionalmaterials like cement both structural capability and measurable response toapplied stresses, strains, cracks and other flaws. In this paper the mainresults of an extensive literature review about CNT/cement composites and theirself-sensing capabilities are summarized and critically revised. The analysisof experimental results and theoretical developments provides useful designcriteria for the fabrication of CNT/cement composites optimized for SHM applicationsin civil engineering.