Environmental effects on <scp>CFRCM</scp> 's piezoresistive behavior and corresponding layered failure modeling

Abstract The functional integration design of carbon fabric reinforced cementitious matrix (CFRCM) materials for smart sensing advances structural health monitoring. However, theoretical models and experimental studies on CFRCM's piezoresistive effects remain incomplete, particularly under practical service conditions. To bridge the gap between the idealized predictive model and complex environmental factors, 81 pull‐out tests were conducted to examine the individual and combined effects of temperature, moisture, and chloride content on the piezoresistive behavior of CFRCM. Results of single‐factor indicate that moisture increase brings about larger peak displacement and initial resistance, temperature rise reduces initial resistance while amplifying elastic‐phase resistance growth, and chloride exposure significantly lowers the peak load. Further analysis reveals coupled effects, such as chloride dissolving in high‐moisture conditions, resulting in lower resistance and moisture‐saturated specimens undergoing freeze expansion in low‐temperature environments, weakening the fiber‐mortar interface bond. When multiple factors coexist, the simulated load is jointly influenced by Cl − ion, water immersion, and temperature effect, causing a deviancy of up to 63.6%. Finally, a refined piezoresistive model and simulation framework for CFRCM pull‐out behavior was proposed with environmental modifications. The load and resistance curves of the entire pull‐out process were simulated, incorporating the equivalent layered failure model. The modified model was verified to be reliable with an accuracy exceeding 95%, providing a theoretical foundation for structural health monitoring using CFRCM composites.