ABOUT THE 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.

International Concrete Abstracts Portal

Showing 1-5 of 12 Abstracts search results

Document: 

SP342

Date: 

July 17, 2020

Publication:

Symposium Papers

Volume:

342

Abstract:

Sponsors: Sponsored by ACI Committees 342, Evaluation of Concrete and 343, Concrete Bridge Design (Joint ACI-ASCE) Editors: Benjamin Z. Dymond and Bruno Massicotte In recent years, both researchers and practicing engineers worldwide have been refining state-of-the-art and emerging technologies for the strength evaluation and design of concrete bridges using advanced computational analysis and load testing methods. Papers discussing the implementation of the following topics were considered for inclusion in this Special Publication: advanced nonlinear modeling and nonlinear finite element analysis (NLFEA), structural versus element rating, determination of structure specific reliability indices, load testing beyond the service level, load testing to failure, and use of continuous monitoring for detecting anomalies. To exchange international experiences among a global group of researchers, ACI Committees 342 and 343 organized two sessions entitled “Advanced Analysis and Testing Methods for Concrete Bridge Evaluation and Design” at the Spring 2019 ACI Convention in Québec City, Québec, Canada. This Special Publication contains the technical papers from experts who presented their work at these sessions. The first session was focused on field and laboratory testing and the second session was focused on analytical work and nonlinear finite element modeling. The technical papers in this Special Publication are organized in the order in which they were presented at the ACI Convention. Overall, in this Special Publication, authors from different backgrounds and geographical locations share their experiences and perspectives on the strength evaluation and design of concrete bridges using advanced computational analysis and load testing methods. Contributions were made from different regions of the world, including Canada, Italy, and the United States, and the technical papers were authored by experts at universities, government agencies, and private companies. The technical papers considered both advanced computational analysis and load testing methods for the strength evaluation and design of concrete bridges.

DOI:

10.14359/51727057


Document: 

SP-342_09

Date: 

June 1, 2020

Author(s):

Denis Mitchell, Bruno Massicotte, William D. Cook, and Emre Yildiz

Publication:

Symposium Papers

Volume:

342

Abstract:

The existing Champlain Bridge is a major structure in Montreal. It contains 50 concrete spans. The 10 ft (3.1 m) deep I-girders span 172 ft (52.4 m) and are post-tensioned. Because the prestressing steel has suffered from corrosion, it was necessary to use advanced techniques to evaluate the performance of these I-girders. Detailed twodimensional non-linear finite element modelling was used to determine the responses at service load and at ultimate. Three-dimensional finite element modelling was carried out to determine the loading for the two-dimensional modelling. The serviceability checks examined if cracking would occur and the strength requirements were evaluated using predicted demand-to-capacity ratios (D/C). These analysis tools also enabled the influence of a number of strengthening techniques to be assessed. The influence of different strengthening techniques on the predicted responses of the diaphragms was also studied. The combinations of strengthening measures were found to be effective in achieving the desired serviceability and strength requirements. Keywords:

DOI:

10.14359/51725942


Document: 

SP-342_10

Date: 

June 1, 2020

Author(s):

Anish Sharma and Serhan Guner

Publication:

Symposium Papers

Volume:

342

Abstract:

Due to the increase in traffic and transported freight in the past decades, a significant number of in-service bridges have been subjected to loads above their original design capacities. Bridge structures typically incorporate deep concrete elements, such as cap beams or bent caps, with higher shear strengths than slender elements. However, many in-service bridges did not account for the deep beam effects in their original design due to the lack of suitable analysis methods at that time. Nonlinear finite element analysis (NLFEA) can provide a better assessment of the load capacity of deep bridge bent beams while accounting for the deep beam action. However, there is little guidance on how to conduct a numerical strength evaluation using the NLFEA. This study presents a nonlinear modeling methodology for the strength evaluation of deep bridge bents while considering advanced concrete behavior such as tension stiffening, compression softening, and dowel action. Five existing bridge bent beams are examined using the proposed methodology. The effectiveness and advantages of the proposed methodology are discussed by comparing the numerical results, including the load-displacement responses, load capacities, cracking patterns and failure modes, with the strut-and-tie and sectional analysis methods. Important modeling considerations are also discussed to assist practitioners in accurately evaluating deep bridge bents.

DOI:

10.14359/51725943


Document: 

SP-342_11

Date: 

June 1, 2020

Author(s):

Yang Yang and Ruili He

Publication:

Symposium Papers

Volume:

342

Abstract:

Concrete columns in curved bridges have reportedly showed high interaction between bending and torsional moments when subjected to design-level earthquake loading. In order to accurately evaluate the performance of curved bridges under earthquake loadings, it is necessary to incorporate the interaction behavior into computational models. However, very limited work has been reported in the literature, which includes finite element models involving threedimensional solid elements and user-developed fiber elements in open-source computing tools; the former involves significant computational effort when multiple levels of earthquake records need to be considered, while the latter is not widely available in analysis tools like OpenSees. This study developed a modeling technique to simulate the interaction between bending and torsional moments in bridge columns through the discretization of the column into longitudinal, transverse, and diagonal elements. In this study, the developed modeling technique was validated against experimental data from a previous study, and case studies on typical curved bridges were presented to show its efficiency in seismic simulation.

DOI:

10.14359/51725944


Document: 

SP-342_02

Date: 

June 1, 2020

Author(s):

Marc Savard and Jean-François Laflamme

Publication:

Symposium Papers

Volume:

342

Abstract:

Several of the first prestressed concrete segmental bridges in North America were built in Quebec, Canada. The Rivière-aux-Mulets bridge was one of them. Built in the early 1960s, this bridge experienced several disorders due to inadequate design criteria enforced at that time. Despite a structural strengthening in the late 1980s, a bridge behavior follow-up has been required to ensure reliability. The structural health monitoring program implemented to track structural disorders, along with results from modal analysis and diagnostic load tests, is presented with a focus on the instrumentation and the data analysis. A three-dimensional finite element model was developed and calibrated using the frequencies and mode shapes detected under ambient traffic conditions. Data analyses showed that the expansion bearings were frozen, causing bending of the associated piers, which generated axial forces in the deck and decompression of concrete in the area surrounding active cracks. This process enables premature failure of prestressing tendons in the vicinity of these cracks, especially those located in the top flange, which is a corrosion-friendly environment. Development of cracks and associated prestress loss caused a reduction in the bridge load-carrying capacity. Analyses of health monitoring data led to acute assessment of the overall bridge structural performance.

DOI:

10.14359/51725935


123

Results Per Page