Experimental Study on the Seismic Performance of Hollow Columns with Fiber Lightweight Aggregate Concrete

To study the seismic performance of hollow columns with fiber lightweight aggregate concrete, a quasi-static test on eight hollow columns with fiber lightweight aggregate concrete under lateral low-cycle reversed loading and axial force is presented in this article. The effects of the dosage of plastic-steel fibers (0, 3, 6 and 9 kg/m3, respectively), steel fibers (25, 50 and 75 kg/m3, respectively) and the axial compression ratio (0.4 and 0.6, respectively) on the seismic mechanical properties such as capacity under lateral load, stiffness, ductility and energy dissipation were investigated, and the main failure morphology and force mechanism of hollow columns with fiber lightweight aggregate concrete under lateral low-cycle reversed loading were revealed. The results showed that (1) the failure modes of hollow columns could be divided into shear failure, bending-shear failure and bending failure; (2) compared with the specimens without fiber, the increase in ductility coefficient of specimens with plastic-steel fiber was 2~33.7%, and that with steel fiber was 30.8~125.7%; the increase in cumulative energy dissipation of specimens with plastic-steel fiber was 5.3~43.7%, and that with steel fiber was 88.9~203.8%, thus indicating that the seismic performance of the specimens could be improved effectively via the incorporation of fibers. The formula of shear capacity under lateral load was proposed, and its calculation results were more reliable when compared with the actual project. A foundation for further research on the seismic performance of hollow columns with fiber lightweight aggregate concrete is provided.