Composite beams composed of rolled steel profile concreted between flanges

Composite beams composed of rolled steel profile concreted between flanges

Building use

Other

Country/Region

Japan

Overview

This technology is a composite structure in which members filled with concrete are columns and beams in a web of steel H-shaped cross-sections, and in addition to realizing a rational cross-section with a simple configuration, it also has excellent workability. In this research, the evaluation methods necessary for the practical design of structures and fire resistance have been proposed.

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

Construction date: 2015
Number of stories: 8
Gross floor area: 6,784m2
Adopted design code: Japan Building Standard act
Engineer(s): Takenaka corporation
Contractor(s): Japanese contractor

Issue and/or innovation

Because it is a new technology, it is necessary to evaluate the rigidity, strength, and fire resistance performance in practical design, and the issue is to propose an evaluation method based on the experimental results.

Reason for composite solution

Due to the following issues in the construction of housing complexes in the context of a shortage of production labor and concrete supply due to the Great East Japan Earthquake in 2011:
1) Early provision of buildings that are not affected by the labor situation
2) High safety in the event of a major earthquake
3) Economic efficiency equivalent to conventional RC housing complexes

Technical details

In this technology, members filled with concrete are used in the web of the H-section of the steel frame to construct the frame structure. Studs and welded wire mesh to prevent falling off are arranged in the web part. This technology has the advantages of improving the rigidity and bearing capacity of each member, rationalizing the steel cross-section by the local buckling restraint effect, and eliminating the need for fireproofing.
In the field of structures, experiments were conducted on the flexural performance and shear performance of beams, and methods for evaluating stiffness and strength were proposed. In the field of fire resistance, fire resistance tests were conducted to determine the relationship between the fire resistance time and the loading bending moment of composites and beams. In addition, by showing that the analysis results were consistent with the test results, it was shown that the behavior of the composite beam in the event of a fire can be predicted by the analysis.

Specific solution/technical details

The above issues were solved by adopting concrete filled H-beams (Concrete Filled H-beams = CFH®: a composite structural technology in which concrete is filled between the flanges of H-beams) with the following technical features:
1) Improvement of structural member rigidity
2) Improvement of steel yield strength
3) Improvement of fire resistance performance (realization of no fireproof covering)
4) Variability to cope with changes in life stages
5) Expansion and flattening of effective interior living space

Impact or effectiveness

The application of CFH® for the outer-frame has resulted in the following effects:
1) High degree of freedom in floor plan
2) 2/3 shorter construction period compared to conventional RC buildings
3) Economic efficiency equivalent to conventional RC buildings
4) Spacious living space equivalent to conventional steel buildings
5) Contribution to reconstruction housing in Kamaishi area, which was severely damaged by the Great East Japan Earthquake
6) Contribution to the reduction of global environmental burden by reducing CO2 emissions and fireproof cladding materials

References / Technical Papers Content

Tooru HIRADE, Hirofumi KANEKO, Yoshio TANNO and Hajime TANIGUCHI, “EVALUATION METHOD FOR STIFFNESS AND STRENGTH OF CONCRETE FILLED H-SHAPED STEEL COMPOSITE BEAM”, J. Struct. Constr. Eng., AU, No. 562, 183-190, Dec., 2002
Akio KODAIRA, Hideo FUJINAKA, Hirokazu OHASHI and Toshihiko NISHIMURA, ”
FIRE RESISTANCE OF THE COMPOSITE BEAMS COMPOSED OF ROLLED STEEL PROFILE CONCRETED BETWEEN FLANGES”, J. Struct. Constr. Eng., AU, No. 563, 193-198, Jan., 2003