Applicability of carbon nanotube-incorporated cement-based composites as a sensor for measuring the carbonation front: an overview

Carbon nanotubes (CNTs) have been widely used in various fields due to their remarkable electrical and mechanical properties. In the construction industry, several studies have been conducted in an attempt to impart conductivity to cement-based composites by incorporating CNTs into the composites. The electrical properties of CNT-incorporated cement-based composites undergo changes due to several factors, allowing one to use these composites as cement-based sensors. Carbonation has been regarded as a significant factor contributing to the deterioration of concrete structures. The reaction between hydrates and dissolved carbon dioxide in concrete leads to the precipitation of calcium carbonate and reduction of pH levels, causing corrosion of reinforcement. Thus, numerous efforts have been dedicated to non-destructively assessing the extent of carbonation of concrete structures. This paper summarizes previous studies on the non-destructive evaluation of the extent of carbonation in concrete. In addition, a preliminary study on the applicability of CNT-incorporated cement-based composites embedded in the concrete structure as sensors for measuring carbonation front will be introduced.