Study on performance of sulfoaluminate cement through hybrid PVA/PET fiber reinforcement based on AE and DIC techniques

This study systematically investigates the reinforcement mechanisms of hybrid rigid polyvinyl alcohol (PVA) and flexible polyester (PET) fibers in sulfoaluminate cement (SAC). Experimental methods included flexural, compressive, and splitting tensile tests to evaluate mechanical properties; acoustic emission (AE) for real-time damage monitoring; digital image correlation (DIC) for strain and crack analysis; scanning electron microscopy (SEM) for microstructural characterization; and fractal dimension analysis for crack complexity quantification. Results indicate that the hybrid fiber system with 0.3 vol% PVA and 0.3 vol% PET significantly enhanced tensile strength, ductility, and crack resistance. AE and DIC data revealed a transition from brittle to ductile failure mode: PVA fibers suppressed microcrack formation through chemical bonding, while PET fibers bridged macrocracks and dissipated energy through physical mechanisms. Microstructural analysis showed a denser interfacial transition zone facilitated by PVA and a stable three-dimensional network formed by PET, with SAC’s low alkalinity contributing to PET’s durability. This work demonstrates a feasible strategy for developing high-performance, ductile, and durable SAC composites using sustainable hybrid polymer fibers, suitable for marine engineering structures.