The Eccentric Compression Performance of Spirally Stiffened Thin-Walled Square Concrete-Filled Steel Tubular Laminated Composite Members

To enhance the local buckling resistance of thin-walled steel pipes and their fire corrosion resistance, a new spirally stiffened square concrete-filled tubular laminated composite member with transverse ribs is proposed. Through four forms combined members for eccentric pressure testing, it was found that: ordinary pipe concrete drum more severe; spiral ribs, limited between stiffening ribs; deformation significantly reduced. By addressing problem cooperative work inner outer structural layers components, that, after setting constraints such as bars, integrity two can be ensured, stress performance improved; compared to concrete, load-carrying capacity 17.9% higher, roughly equivalent. Spiral form spatial restraint, in addition increasing bending stiffness, manifest an overall restraint role limiting lateral pipe, whereas vertical stiffness insignificant. Based on test evidence, influences width thickness ratio pitch were determined, reasonable measures given. N–M relationship curve, limit damage compression tension under eccentricity obtained at about 0.9. Finally, method calculating compressive ultimate load this