A comprehensive review on the performance, mechanisms and design of polyvinyl alcohol (PVA)-enabled self-healing concrete

This review critically examines the roles, mechanisms, and future potential of polyvinyl alcohol (PVA) in self-healing concrete, with particular emphasis on the effects of polymer form, degree of polymerization (DP), and degree of alcoholysis (DA). Most of existing studies focus predominantly on PVA fibers for crack control. This review provides a comprehensive comparison between fiber-based and soluble PVA systems and evaluates their distinct influences on fresh properties, mechanical performance, durability, permeability, and self-healing efficiency. Recent experimental and simulation studies indicate that while PVA fibers mainly enhance autogenous self-healing by refining crack widths and providing nucleation sites, soluble PVA—especially low-DP variants—shows potential to actively promote autonomous healing through calcium-ion complexation and accelerated carbonate precipitation. Based on these comparisons and discussions, this review proposes a conceptual extension of the complexation–precipitation theory as a potential unifying framework to interpret PVA-enabled self-healing behavior. Key challenges related to workability, strength trade-offs, long-term durability, and cost are critically assessed. Finally, emerging perspectives are discussed, including synergistic use of multiscale PVA systems, integration with biomineralisation agents, and broader extension of complexation-based healing strategies. This review aims to bridge material engineering performance with underlying chemical mechanisms, providing guidance for the rational design of next-generation self-healing concrete systems incorporating PVA. • The effects of PVA on self-healing concrete depend on its form of incorporation. • Incorporation of PVA inevitably alters the fresh and hardened properties of concrete. • The polyhydroxyl molecular structure of PVA enables weak complexation with Ca 2+ ions. • Excessive PVA introduces porosity or retards hydration, highlighting the need for optimisation. • Research on the synergistic combination of PVA fibers with low-DP soluble PVA is promising.