Directionally sensitive cement-based sensor using carbon nanotube and carbonyl iron powder (CNT@CIP)-based nanohybrid clusters

Cement-based sensors have been highlighted for using as structural health monitoring sensors; however, the conventional cement-based sensors can only detect the levels of applied loading not the direction of the loading. Therefore, this study proposes a new method for developing cement-based sensors which can detect the levels of applied loadings with their direction. The proposed method involves using carbon nanotube and carbonyl iron powder (CNT@CIP)-based nanohybrid clusters, which are added to the cement-based sensors during fabrication, and controlling their conductive networks through magnetization curing. The fabricated cement-based sensors are then tested for piezoresistive sensing. The experimental outcomes indicated directional sensitivity values of 3.12%, 2.47%, and 0.98%/MPa stress sensitivity in horizontal, random, and vertical sensors. In addition, their long-term sensing capabilities are predicted using a long short-term memory (LSTM) model. The findings of this study could be useful in developing multi-directional cement-basd sensors and predicting their long-term sensing capabilities.