Experimental Study on the Axial Compressive Behavior of an Aluminum Alloy Foam Concrete Composite Column

Abstract

Highlights What are the main findings? Axial compression tests showed that cracks mainly initiated and propagated along the diamond-shaped diagonal-braced surfaces, with the middle column segment being the most vulnerable region. Strain analysis indicated that foam concrete dominated the early-stage axial resistance, while the semi-passive confinement effect of the aluminum alloy frame weakened as the load increased. What are the implications of the main findings? The diagonal-braced region and middle column segment should be considered critical locations in the design and damage evaluation of aluminum alloy–foam concrete composite columns. Finite element results suggest that, within the investigated numerical range, two interlocking keys, zero cover thickness, and a 3 mm frame thickness can improve synergistic load-sharing and axial capacity. Abstract A lightweight and high-strength structural system is increasingly demanded in prefabricated and sustainable construction; however, accurately evaluating the mechanical behavior of novel composite members remains challenging. This study proposes an aluminum alloy foam concrete composite column consisting of an embedded aluminum alloy frame and foam concrete infill. Material tests, a full-scale axial compression test, and finite element-based parametric analyses were conducted to verify the hypothesis that composite action between the embedded aluminum alloy frame and foam concrete governs the axial load-transfer mechanism and bearing capacity of the proposed column. The results show that initial cracking mainly occurred in the middle region of the column along the diagonal brace direction, while the composite column maintained favorable elastic performance under relatively high load levels. The aluminum alloy frame provided a semi-passive confinement effect on the foam concrete, although this effect gradually weakened with increasing load due to lateral deformation of the diagonal braces. Moreover, an appropriate arrangement of interlocking keys significantly improved the composite action and overall stability of the column. These findings provide experimental and numerical evidence for assessing the axial compression performance of aluminum alloy foam concrete composite columns and offer guidance for the design and optimization of this novel lightweight structural system.