A review on the impact resistance and fire performance of 3D 2026 Next Mater

3D-printed concrete (3DPC) is progressively being adopted in the construction industry, for applications in which resistance to impact loading and fire exposure is critical. Notably, the layer-by-layer deposition process introduces anisotropic interlayer interfaces that fundamentally govern both the strain-rate-sensitive dynamic response under impact loading, as well as the preferential spalling pathways and effective heat transfer under fire exposure. Although existing review studies have addressed the mechanical performance, anisotropy, microstructure, durability, mix design, and rheology of 3DPC, a comprehensive assessment integrating both impact resistance and fire performance remains lacking. Therefore, this article synthesises recent advancements in the impact resistance and fire performance of 3DPC within a unified framework. Furthermore, this review systematically investigates the effects of different fibre types, supplementary cementitious materials (SCMs), printing parameters, anisotropic and aggregate characteristics, and interlayer interface properties on both the impact resistance and fire performance of 3DPC. Specifically, the study critically discusses the impact testing methods, namely drop-weight, Split Hopkinson Pressure Bar (SHPB), and projectile impact tests together with the associated strain-rate effects, dynamic increase factors (DIF), and constitutive relationships used in different numerical approaches. In addition, the fire performance of 3DPC is comprehensively evaluated through a review of different fire performance assessment methodologies, experimental fire testing approaches involving different component types, shapes, and configurations, fire behaviour influenced by anisotropy, interlayer architecture, and microstructural characteristics, as well as relevant numerical models.