Concrete-filled aluminum alloy tubular stub columns under compression: current status and capacity prediction methods

Concrete-filled aluminum alloy tube (CFAT) is a new type of composite structure with excellent durability and light weight, having broad application prospects in corrosion-resistant structures. The research progress of CFAT and concrete-filled double-skin aluminum alloy tubular (CFDAT) short columns is systematically reviewed. Material properties of aluminum alloy and concrete used in CFATs are first introduced. Existing experimental, finite element (FE) and theoretical studies on the axial compressive behavior (e.g., experimental setup, FE modeling method, failure modes, confinement mechanisms, ultimate bearing capacity) are reviewed. Effects of the key factors, such as material strength, cross-sectional form, diameter-to-thickness ratio, confinement coefficient and void ratio, on short columns' structural behavior are discussed. In addition, a database containing 254 CFATs and 91 CFDATs has been established. Prediction accuracy of existing bearing capacity calculation models in current design codes and research papers is assessed, and their applicability and limitations are discussed. New models are then proposed to explicitly consider the local buckling of aluminum alloy tubes and the effect of concrete strength, and these models exhibit satisfactory accuracy. Finally, future research directions on this topic are suggested.