Design Theory of High-Ductility Cementitious Composites Reinforced with PVA and PE Fibers

Cementitious composites suffer from inherent brittleness, low toughness, and limited crack resistance, restricting their performance in complex service environments. Engineered Cementitious Composites (ECC) achieve tensile strain-hardening and multiple cracking through fiber bridging, but PVA and PE fibers differ significantly in interfacial bonding. This review focuses on three aspects: 1) Micromechanical design criteria: coordination of crack-tip fracture and fiber bridging load/energy, considering matrix heterogeneity, defect distribution, and fiber orientation; 2) PVA-ECC design theory: interfacial control of debonding–slip energy distribution and its effect on macroscopic tensile response; 3) PE-ECC model modification: coupled effects of fiber tilt, interface wear, and slip hardening, and strategies for bridging-model adjustments. Unlike previous ECC reviews that emphasize composition and performance, this study systematically compares PVA and PE systems in design-theory evolution and bridging-model modification. Future work should develop bridging models capturing interfacial evolution under age, environment, and multi-field conditions, integrating friction, slip, fiber tilt, and damage into a unified micro–macro framework to enhance predictive consistency and engineering applicability.