Abstract
Three-dimensional concrete printing enables automated, formwork-free, and resource-efficient fabrication of cementitious components. However, its layered architecture creates climate-dependent durability risks that conventional concrete tests and homogeneous transport assumptions cannot adequately capture. This critical review develops a climate-process-microstructure-transport-degradation-durability framework for 3D-printed concrete and evaluates evidence across five performance-based exposure regimes: cold, marine, hot-arid, hot-humid, and temperate. The evidence identifies connected interfaces, filament boundaries, cold joints, surface defects, and non-uniform curing as pathway amplifiers that govern directional transport and localized damage. These effects remain strongly dependent on material, printer, geometry, orientation, and protocol. Moreover, the importance of test orientation, interlayer interval, curing, and component-scale and geometry variability are highlighted. Accordingly, reported data are translated into evidence-informed mixture-process-curing design ranges with climate-specific validation criteria rather than universal limits. Furthermore, transport reporting in three directions, interface-sensitive durability metrics, and an evidence-maturity hierarchy from printed coupons to monitored field structures are proposed. Service-life calculations remain system-specific and model-assisted until anisotropy, interfaces, curing, component scale, and field exposure are incorporated and validated.