Toshikatsu Ichinose

Splitting Bond Failure of Columns Under Seismic Action

ACI Structural Journal, V. 92, No. 5, September-October 1995. Received April 11, 1994, and reviewed under Institute publication policies. Copyright

On the Seismic Response of the Faculty of Architecture and Engineering Building at Tohoku University

The Faculty of Architecture and Engineering Building at Tohoku University survived two strong ground motions. This is not surprising because the structure was stiff and strong. What is surprising is that the first ground motion did not cause severe structural damage but the second one caused so much structural damage that the building had to be evacuated and demolished. The damage occurred despite two key facts: (1) the intensities of the mentioned ground motions are understood to have been similar and (2) the building was strengthened after the first motion (and before the second) following stringent standards.

Flexure Mechanism and Deformation at Bending-Compression Failure of RC Structural Walls

AbstractThe objective of the present study is to contribute to the understanding of the seismic behavior and performance of reinforced concrete flexure-dominated walls when their boundaries are sub...

STRENGTH AND RIGIDITY OF STEEL GRADE BEAMS COVERED WITH PLAIN CONCRETE

This paper proposes grade beams made of H-shaped steel covered with plain concrete (SC) for superstructure made of steel. The SC grade beams have three merits over conventional reinforced concrete beams: improved construction accuracy, easier connection between grade beam and steel superstructure, and shorter construction period. Full-scale tests of SC and bare steel beams were conducted with different sections and spans. The initial stiffnesses of SC beams were two to three times of those of bare steel beam. The strengths of SC beams were three to seven times of those of bare steel beam, because torsional deformations were prevented.

CONSIDERATION ON SIDE-SPLITTING BOND STRENGTH OF R/C BEAM WITH MULTI-LAYERED REINFORCEMENT

There have been many pull-out tests indicating that the bond strengths of the bars in the second layer are smaller than those in the first layer. On the other hand, test results of RC beam indicate that the bond strengths of the cut-off bars in the second layer are larger than those in the first layer. To examine this contradiction, a new method is proposed, where the direct shear failure of the concrete at the reinforcement layer is considered rather than the bond stress of each bar. The proposed method is successfully applied to the previous test results of RC beams with multi-layered reinforcement.

Damages to Reinforced Concrete Buildings

Typical damages to reinforced concrete buildings, both by the ground motions and the tsunami waves, are outlined in this section. The report herein is based primarily on the field survey of the AIJ members and collected through the members of the Reinforced Concrete Steering Committee of AIJ. The typical damages to reinforced concrete buildings are described below through the reports on the buildings selected and available for detailed survey. The damage reports below are translated selectively from the Chap. 6, Sect. 6.2 of AIJ report in Japanese version, which contains more photos and figures, especially on the structural plans as well as the damage rate evaluation of members. The reports on the buildings below are arranged as from the Japanese version: (1) school buildings located from north to south (Iwate, Miyagi, Fukushima and Kanto areas), (2) government offices, (3) residential buildings.

EXPERIMENTS ON ARAMID FIBER RETROFIT FOR RC COLUMNS WITH WALLS

A new method for retrofitting RC columns having walls is proposed. The method is as follows: paste thin aramid fiber sheets on the column and bind the column with narrow aramid fiber sheets at large intervals. And, experiments on the shear strength, the deformation capacity, the bond performance and the applicability to short column were conducted. As a result, (1) the shear strength, the deformation capacity and the bond behavior could improve using the proposed method; (2) the mechanism of shear failure was different depending on the axial load.