Research on the mechanical properties of assembled TRC permanent formwork composite columns

To further promote the prefabricated development of textile-reinforced concrete (TRC) permanent formworks, in this paper, the effects of TRC formwork form, assembly method and assembly direction on the mechanical properties of composite columns with TRC permanent formworks are studied by performing axial compression tests. The results show that the failure of these composite columns is divided into three typical failure modes, namely, corner fracture failure, bolt hole shear failure, and splicing joint crack failure. Compared with plain concrete columns, TRC permanent formwork composite columns can better control the development of cracks and improve the crack development mode under compression. A comparison of different forms of TRC formworks shows that the ultimate bearing capacity of a composite column with flat-plate TRC formworks is higher than that of composite columns with L-shaped formworks. Compared with other assembly methods, the composite column with a bolt, angle steel and high-strength nonshrinkage grouting material achieves the maximum ultimate bearing capacity. Furthermore, the bearing capacity of the composite column with the TRC formwork assembled in two directions is weaker than that of the composite column with the TRC formwork assembled in only one direction. Finally, by analyzing the bearing mechanism of the TRC permanent formwork composite column, the calculation model of the ultimate bearing capacity of the composite column is obtained, and the calculated value is in good agreement with the test value.