Strain-Detecting Properties of Strain-hardening Cement Composite (SHCC) Sensors Embedded in the Compressive Zone of Notched SFRC Beams in Flexure

A strain-detecting sensor with a smart strain-ardening cement composite ((SHCC)-H-2) incorporating steel fibers and multi-walled carbon nanotubes (MWCNTs) was developed and tested. This study investigated the piezoresistive responses of (SHCC)-H-2-based sensors embedded in the flexural compressive zone of notched steel fiber-reinforced concrete (SFRC) beams under monotonic and repeated loadings. Two types of flexural loadings were used to investigate the range and stability of the strain-detecting capacity of the embedded (SHCC)-H-2-based sensors. The results indicate that the variation in the fractional change in resistivity (FCR) of the embedded sensor was consistent with the flexural compressive strain changes, which exhibited acceptable sensitivity and reversibility. Therefore, the results confirm that (SHCC)-H-2-based sensor embedded in structural members exhibits excellent strain-detecting properties; it can be used to monitor strain and damage to infrastructure.