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Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Showing 1-5 of 18 Abstracts search results
Document:
SP187-09
Date:
June 1, 1999
Author(s):
J. B. Mander and C.-T. Cheng
Publication:
Symposium Papers
Volume:
187
Abstract:
As low cycle fatigue failure in the longitudinal reinforcement is unavoidable, it necessitates the concept of using replaceable plastic hinges in which specially-detailed reinforcing fuse-bars are installed. Three one-third scale model pier specimens were constructed. The first renewable-hinge column was tested and repaired five times. The second pre-cast column was also constructed using the fuse-bar connections and subsequently repaired ten times. For comparative purposes, a conventionally reinforced column was constructed and tested. It was found that each of the repaired columns performed as well as the undamaged virgin columns. This new approach to construction enables rapid restoration to full service following a damaging earthquake.
DOI:
10.14359/5599
SP187-10
A. Griezic, W. D. Cook, and D. Mitchell
A series of five bridge columns with concrete hinges at their bases were tested under reversed cyclic loading to determine their behavior. A method for predicting the responses, which accounts for the effects of confinement on the concrete hinge region and yield penetration is presented. A simple retrofit technique for two-way hinges, using dry-pack grout, was investigated. A method for retrofitting one-way hinges by using an added reinforced concrete footing block, together with concrete in-fitted steel jacketing was tested. The reversed cyclic loading response, before and after retrofit are compared and means of both designing the retrofit and predicting the responses are presented.
10.14359/5600
SP187-11
S. Mazzoni, F. Zayati, J. P. Moehle, and S. A. Mahin
A program of field a laboratory tests to study the seismic response of reinforced-concrete double-deck bridge structures has been conduced at the University of California Berkeley. The research was prompted by the poor performance of these structures during the 1989 Loma Prieta Earthquake. The program had three phases of testing. The first phase was conducted in-situ immediately after the earthquake on a section of the Cypress Street Viaduct that had not collapsed. This test showed the need for confinement in the critical beam column joint region as well as the need for a ductile lateral-load-resisting system. The second phase of testing was the proof test of a comprehensive retrofit concept for a bent of the Alemany Freeway. The test showed that a ductile system, combined with a conservatively designed beam-column connection, provides adequate structural performance under unidirectional and bidirectional lateral loading. The third phase of testing focused on the current design criteria for beam-column connections in ductile double-deck bridge structures. In this phase of testing, two one-third scale models of beam-column connections in ductile frames designed according to current criteria were tested in the laboratory. Results from this test series showed that proper detailing, without excessive amount of reinforcement, increases the load-resisting capacity of beam-column connections and relocates the yield mechanism from the joint to the column. The goal of this paper is to provide the reader with a comprehensive overview of the work.
10.14359/5601
SP187-12
S. Pujol, J. A. Ramfrez, and M. A. Sozen
The current seismic design philosophy allows nonlinear behavior of the structure to reduce strength requirements. This implies that the structure must be able to retain its integrity under cycles of displacement into the nonlinear range. The structure has to be tough. Evaluation of experimental results from 15 series of tests reported by various investigators has shown that the limiting drift capacity of a reinforced concrete column proportioned to resist earthquake effects through energy dissipation in the nonlinear range of response may be determined simply by considering two parameters: 1) the aspect ratio, and 2) the transverse reinforcement index.
10.14359/5602
SP187-13
N. Wehbe and M. S. Saiidi
This paper presents an analytical study on the seismic vulnerability of flared reinforced concrete bridge columns with structural flares. Four representative bridges, located in Northern Nevada, are included in the study. The flared columns in these bridges have similar architectural features and cross sectional dimensions but are reinforced with different steel arrangements. The "push-over" method of analysis is applied to predict the locations of plastic hinges in the columns and the corresponding shear demands under lateral earthquake loading material over strength on the ductility and the flexural capacity of different cross sections along the column height. It is shown that in parabolic structural flares the location of plastic hinges is strongly dependent on the longitudinal steel arrangement and that the shear capacity of flared columns without core reinforcement may be inadequate under lateral earthquake loading.
10.14359/5603
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