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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 23 Abstracts search results
Document:
SP120-13
Date:
June 1, 1990
Author(s):
Christian Menn and Paul Gauvreau
Publication:
Symposium Papers
Volume:
120
Abstract:
A research project is currently underway at the Swiss Federal Institute of Technology, Zurich, to establish the feasibility of an alternative structural system for short-span highway bridges. Concerns over the long-term durability of structural systems currently used in the 25 to 40 m span range provided the primary motivation for the study. The proposed system consists of a solid concrete slab that is externally prestressed. The external tendons are deviated at the third points of each span using struts. A 1:3-scale model bridge has been constructed and is currently being tested to verify the behavior of the bridge under permanent, service, and ultimate static loads, as well as dynamic and fatigue loads. The favorable results obtained thus far have confirmed the feasibility of the proposed structural system, and will serve as a basis for extending the concept to spans greater than 40 m in length.
DOI:
10.14359/3266
SP120-20
Jeanne M. Nagele, Sankar C. Das, and Reda M. Bakeer
The purpose of this investigation was to examine the forces developing in the dome of a prestressed concrete nuclear containment structure due to prestressing of vertical tendons. A computer program was developed for personal computers to evaluate the effect of prestressing forces. A parametric study was conducted, using the program, to examine the effects of dimensions, prestressing force, properties of tendons, etc. on the resulting stresses in the dome.
10.14359/2862
SP120-21
Eilhard WoelfelI
In the near future, prestressed concrete structures will be designed in Europe according to Eurocode 2 (EC 2). The EC 2 principles governing the design of structures with bonded tendons and with external tendons are given in this paper, and a comparison is made between the structural behavior of the two different types of structures. It is shown that the reliability of both is comparable if the characteristic strain due to prestressing is introduced in the calculations.
10.14359/2865
SP120-22
A. S. Nowak, A. E. Naaman, and S. C.Ting
Evaluation of existing bridges is an important part of the strategy of dealing with the deteriorating infrastructure. Load and resistance parameters are random variables because of uncertainties in load components, material properties, and dimensions. Therefore, the reliability of a structure is a convenient measure of its performance. The load and resistance models are first summarized. The major load components in bridges are dead load and live load. The live load model is based on the weigh-in-motion studies. Girder distribution factors are derived using special computer procedures for bridge analysis. Behavior of composite girders is considered using a nonlinear model. The basic characteristic of the section is the moment-curvature relationship. The reliability is measured in terms of the reliability index. The approach is demonstrated on evaluation of a prestressed concrete girder bridge. Three cases are considered: original design condition, damaged with corroded strands, and repaired by external prestressing. The load components and load-carrying capacities are evaluated and then the reliability indexes are calculated for the three cases.
10.14359/2868
SP120-15
Robert J. F. Macgregor, Michael E. Kreger, and John E. Breen
An experimental investigation was conducted to examine the service and ultimate load behavior of segmentally precast box girder bridges with external post-tensioning tendons. A primary interest of this study was to examine the effect of joint type (dry versus epoxied joints) on the stiffness, strength, and ductility of the structure. A three-span reduced scale segmental box girder model was constructed, then tested in three stages. Flexural behavior was examined first, then shear tests were conducted on the damaged structure. Test results and observations are presented.
10.14359/3277
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