Axial loading tests of thin-walled circular steel tubes infilled with cast-in-place concrete and precast segments containing DCLs

Large precast segments (PSs), prefabricated with DCLs and FC, are proposed to be installed into hollow steel tubes which are then poured full of cast-in-place concrete (CC). The resulting clad, composite columns were examined in full-scale axial compression tests. The key variables were the size and number of PSs assembled in each single tube, and the compressive strength of CC. Using higher strength CC was found to somewhat enhance a column's compression resistance, but it compromised the column's axial deformability significantly. A homogenization-based design equation is formulated, which is shown to predict quite well the axial capacity of the proposed columns. Overall, the semi-precast columns proposed are easy-to-construct, and behave comparably to their cast-in-situ counterparts, showing potential for future precast applications.