Composite frame system called Reinforced Concrete Steel Tube (RCST) system

Composite frame system called Reinforced Concrete Steel Tube (RCST) system

Building use

Complex building

Country/Region

Japan

Overview

The RCST system consists of concrete-filled steel-tube columns, H-shaped steel beams and beam-column joints with steel cover plates for confinement. Column steel tubes are not welded to the beam-column joint, which leads to the rapid erection of the upper column on the floor. Columns and beam-column joints are easily connected by casting concrete and by the connecting rebars arranged through the upper/lower columns and the beam-column joints. The system has been mainly applied to mid or low-rise buildings such as logistics and commercial facilities so far.

Basic information (construction date, number of stories, gross floor area, adopted design code, engineer(s), Contractor(s), etc.)

Construction date: 2019
Number of stories: 5
Gross floor area: 60,000m2
Adopted design code: Japan Building Standards Act; Japanese prequalified design code
engineer(s): Shimizu corporation
Contractor(s): Shimizu corporation

Reason for composite solution

The proposed structure is compared to conventional structures such as steel structures, the weight of steel materials can be reduced, and the total cost of construction materials can be reduced. In addition, compared to reinforced concrete structures, the construction period can be greatly shortened.

Technical details

Both the top and bottom of column steel-tubes are not welded to beam-column joints, leading to the rapid erection of the upper column on the floor. Columns and beam-column joints are easily connected by casting concrete and by the connecting rebars arranged through the upper/lower columns and the beam-column joints. Thus, RCST structures are designed in accordance with the R/C design code for column ends, the steel design code for steel beams, and the conventional RCST design method for joints and column shafts. The RCST design method for joints refers to another composite system called RCSS (Reinforced-Concrete & Steel System).

References / Technical Papers Content

2020. “EFFECTS OF MEMBER CONFIGURATIONS ON SHEAR CAPACITIES OF BEAM-COLUMN JOINTS CONSTRUCTED BY “RCST” COMPOSITE SYSTEM” 17th World Conference on Earthquake Engineering, Sendai, Japan, 2i-0057, 1-12