The behavior of cold‐formed steel geopolimeric composites

Abstract

Geopolymer concrete‐filled cold formed steel composite beams can exhibit high durability and adequate strength. The geopolymer concrete is used to manufacture the cold‐formed steel tubular composite beam due to the significant advantages, such as greater in strength resisting capacity, higher‐energy dissipation capacity, and more stiffness than the regular one. This paper reports an experimental investigation on the behavior of rectangular geopolymer concrete‐filled cold‐formed steel composite beams. In order to investigate the mechanical behavior (such as flexural, shear, and torsion) of geopolymer concrete‐filled cold‐formed steel tubular composite beams (GCFTBs), 48 beam samples were tested. The 16‐GCFTBs and another 16‐GCFTBs were tested under flexural and overhanging, respectively, which the 16‐GCFTBs were tested under pure torsion. The relationships for load–displacement, torsional moment‐rotation angle, energy dissipation capacity, ductility, and failure mode were analyzed. The test results showed that the increase in cross‐sectional area and curing temperature had a significant effect on bending, shear and torsion behavior. Although the increase in the cross‐section ratio (height/width) increased the bending moment capacity, it decreased the displacement capacity and caused a decrease in ductility. Curing conditions and cross‐section ratio affected strength, displacement capacity, and experimental modulus of elasticity in both bending and shear tests. Increasing the cross‐section ratio and curing temperature resulted in an increase in ductility. Contrary to bending test and shear test, curing temperature, and cross‐section ratio increased both torsional moment strength and rotation angle in torsional moment tests.