Reinforced concrete column with in situ cast core - has grooves for shear transmission between tube and core

摘要

The precast reinforced concrete tube (1) of rectangular or circular cross-section has a cylindrical cavity (2). The cavity is formed with recesses (4, 5) which may be annular, helical or a series of square indentations arranged in rows. An in situ concrete core is poured into the tube, and takes up the shape of the recesses. - The keyed contact between the tube and the core is effective in transmitting axial shear stresses, ensuring good stress distribution in the column. Flexible tinplate formwork is used to cast the tube.