Doctoral Dissertations

Author

Xiaofei Ying

Abstract

"This study is aimed to develop a new seismic retrofit technique of reinforced concrete (RC) beams, columns, and their joints with lightweight steel sheets and steel plates, to validate the retrofit technique with testing of two 4/5-scaled beam-column assemblage specimens, and to develop a strut-and-tie model to ascertain the force transfer mechanism of beam-column joints under seismic loads. Because of the introduction of thin steel sheets, weld joints that were used in the conventional steel jacket of RC columns could be costly in field applications. Nailed joints of two types, interlocked and lap-spliced, were therefore proposed in this study. Each type of the nailed joints was evaluated by testing lap-spliced specimens and concrete rings under quasi-static loading. Test results indicated that an interlocked joint of 6 inches wide with 2 rows of 5 nails failed in ductile bearing of nails against steel sheets with or without rotation of nails provided a minimum gap of 0.5 in. is available at both ends of each sheet Similarly, a lap- spliced joint revealed a ductile bearing failure mode when 5 rows of 10 nails were used. The proposed retrofitting technique can significantly improve the seismic performance of beam-column assemblages, especially with post-tension of the beam. In comparison with the unretrofitted specimen that was tested by Ereckson and failed in column shear at displacement ductility of 2.5, the displacement ductility capacity of the two retrofitted specimens was increased to 8 without post-tensioning and 12 with post-tensioning, corresponding to the pullout and fracture of column longitudinal bars, respectively. No brittle shear failure of the retrofitted columns and joints was observed throughout the testing program. The strut-and-tie model can simulate the tension forces in instrumented reinforcing bars that were in good agreement with the test results"--Abstract, page iii.

Advisor(s)

Chen, Genda

Committee Member(s)

Silva, Pedro Franco
LaBoube, Roger A.
Belarbi, Abdeldjelil
Dharani, Lokeswarappa R.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering

Sponsor(s)

United States. Federal Highway Administration
Missouri. Department of Transportation

Publisher

University of Missouri--Rolla

Publication Date

Fall 2006

Pagination

xvii, 149 pages

Note about bibliography

Includes bibliographical references (pages 144-148).

Rights

© 2006 Xiaofei Ying, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Library of Congress Subject Headings

Columns, Concrete -- Design and construction
Concrete bridges -- Maintenance and repair
Concrete construction -- Joints
Earthquake resistant design -- Testing
Reinforced concrete construction -- Maintenance and repair
Steel

Thesis Number

T 9013

Print OCLC #

85844727

Electronic OCLC #

993782457

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

http://laurel.lso.missouri.edu/record=b5795184~S5

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