Real-time monitoring of structures under extreme loading using smart composite-based embeddable sensors

Abstract

Cementitious composites reinforced with conductive nanoparticles, also known as smart composite-based sensors, are emerging as novel sensors for real-time monitoring of structures. The present study deals with the development of embeddable smart composite-based sensor (called as eSCS), for monitoring the damage evolution in large-scale beam-column (B-C) sub-assemblages. Firstly, a systematic approach has been developed to fabricate the sensors through incorporation of functionalized (-COOH) multi-walled carbon nanotubes (MWCNTs). The optimum dosage of CNTs required for developing sensors with maximum conductivity and piezo-resistivity was ascertained by determining the percolation threshold limit. The best performing eSCS was then successfully embedded at the critical locations of full-scale B-C joint specimens. The embedded sensors are used, for the first time, for damage monitoring of the B-C sub-assemblages subjected to reverse cyclic loadings. From the study, it is found that eSCS with 0.50 wt.% COOH-MWCNT shows excellent piezoresistive behaviour and gauge factors are found to be approximately 730, 457 and 396 for the applied compressive stress ranges of 2–4, 2–6 and 2–8 MPa, respectively. The embedded sensors showed the excellent strain sensing capability under reverse cyclic loading. The present study demonstrates the suitability of embedded eSCS sensors for robust structural health monitoring applications.

Performance of Self-Sensing Cement-Stabilized Sand under Various Loading Conditions

“…Among other factors, the stress level induced by the applied external load is one of the main factors affecting the piezoresistive performance of self-sensing cementitious composites [ 92 , 93 , 94 ]. In this section, the FCR changes in self-sensing cement-stabilized sand containing 4% MWCNT/GNP were evaluated under the loading conditions shown in Figure 3 e by applying various stress levels ranging from 63 kPa to 3804 kPa, as illustrated in Figure 8 and Figure 9 .…”

Smart cement‐sensor composite: The evolution of nanomaterial in developing sensor for structural integrity

“…235 In SHM application such as railway sleepers, 236 vibrations, 58 structure deformations, 237 dynamic load behavior, 238 aircraft structures, 239 self-cleaning, 240 stress strain behavior of concrete, 28 and to monitor the performance of the RC beams 241 and beam-column of large scale sub-assemblage. 242 This paves the way for the application of selfsensing sensors with high precision and easy installation in SHM to attain smart and sustainable infrastructures. 243 Figure 21a,b show the application of sensors in structural elements and the signal measuring method to monitor the structure.…”

“…The SSCM incorporated with nanomaterial possess multifunctional properties that are used appropriately in various field application such as to monitor high speed rail infrastructures, 130 in traffic detection, 233 , 234 smart pavements by weigh‐in‐motion (WIM) sensing 235 . In SHM application such as railway sleepers, 236 vibrations, 58 structure deformations, 237 dynamic load behavior, 238 aircraft structures, 239 self‐cleaning, 240 stress strain behavior of concrete, 28 and to monitor the performance of the RC beams 241 and beam‐column of large scale sub‐assemblage 242 . This paves the way for the application of self‐sensing sensors with high precision and easy installation in SHM to attain smart and sustainable infrastructures 243 .…”

Performance of Self-Sensing Cementitious Composite under Various Loading Conditions

“…Among other factors, the stress level induced by the applied external load is one of the main factors affecting the piezoresistive performance of self-sensing cementitious composites [92][93][94]. In this section, the FCR changes in self-sensing cement-stabilized sand containing 4% MWCNT/GNP were evaluated under the loading conditions shown in Figure 3e by applying various stress levels ranging from 63 kPa to 3804 kPa, as illustrated in Figures 8 and 9.…”