Ultraductile Cementitious Structural Health Monitoring Coating: Waterborne Polymer Biomimetic Muscle and Polyhedral Oligomeric Silsesquioxane‐Assisted C‐S‐H Dispersion.

Cement‐based sensors (CBSs) have demonstrated potential in structural health monitoring (SHM) despite rare applications due to their poor flexibility and sensing accuracy/protection with robustness. Herein, a promising strategy is reported to design a waterborne epoxy resin (WEP)‐modified cement‐based composite coating sensorcapable of simultaneous stable SHM and durable protection. The interpenetrating network (IPN) formed by WEP within cement paste is bionic to the toughness and crack resistance of biological muscle tissue and balances the ion permeation performance and polarization of hydration products. The polymerization‐redispersion progress and mechanism of calcium silicate hydrate (C‐S‐H) gel modified with [3‐(2‐aminoethylamino)‐propyl]trimethoxysilane silsesquioxane (C‐POSS) are characterized and revealed. The results show that the muscle‐like IPN increases the cement‐based coatings' maximum deflection angle to 30° and improves the monitoring accuracy of compressive, tensile, and fatigue microchanges of concrete structures to more than 95%. The POSS···Ca2+···C‐S‐H interaction in C‐POSS partially transferred the intra‐adhesive hydrogen bonds surrounding the nanoconducer into electrostatic bridging ones to maintain an excellent electromechanical conductive dispersion. [ABSTRACT FROM AUTHOR]