TOP-DOWN CONSTRUCTION USING PRECAST ULTRA HIGH STRENGTH CONCRETE BASEMENT COLUMNS AND QUALITY CONTROL OF ACTUAL BUILDING OPERATIONS

Abstract

The top-down construction method using pre-cast concrete for basement columns is more effective in improved quality of concrete, shorter construction time and economy of labor compared with traditional top-down method, requiring no column construction under the ground floor after excavation. This paper first describes the production planning and the implementation of the top-down construction method applied to an actual high-rise building using pre-cast ultra high-strength concrete with a design strength of 100 MPa for basement columns. The paper then proceeds to report on the results of the quality control tests of the high-strength concrete.