Strengthening Historic Covered Bridges to Carry Modern Traffic
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Graduate Theses, Dissertations, and Problem Reports 2003 Strengthening historic covered bridges to carry modern traffic Rex A. Cyphers West Virginia University Follow this and additional works at: https://researchrepository.wvu.edu/etd Recommended Citation Cyphers, Rex A., "Strengthening historic covered bridges to carry modern traffic" (2003). Graduate Theses, Dissertations, and Problem Reports. 1345. https://researchrepository.wvu.edu/etd/1345 This Thesis is protected by copyright and/or related rights. It has been brought to you by the The Research Repository @ WVU with permission from the rights-holder(s). You are free to use this Thesis in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you must obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Thesis has been accepted for inclusion in WVU Graduate Theses, Dissertations, and Problem Reports collection by an authorized administrator of The Research Repository @ WVU. For more information, please contact [email protected]. Strengthening Historic Covered Bridges to Carry Modern Traffic By Rex A. Cyphers Thesis submitted to the College of Engineering and Mineral Resources at West Virginia University in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering Hota V.S. GangaRao, Ph.D., P.E., Chair Emory L. Kemp, Ph.D., P.E. Udaya B. Halabe, Ph.D., P.E. Samer H. Petro, P.E. Department of Civil and Environmental Engineering Morgantown, West Virginia 2003 Key Words: Covered Bridges, Timber Bridges, Historic Preservation, GFRP ABSTRACT Strengthening Historic Covered Bridges to Carry Modern Traffic Rex A. Cyphers The focus of this study was to develop means and methods to strengthen timber superstructural components of historic covered bridges using Glass Fiber Reinforced Polymer (GFRP) composite materials. The strengthening methodologies developed during this research project were designed to conform to the Secretary of the Interior’s Standards for the Treatment of Historic Properties. More specifically, tension and bending tests were conducted to establish bond strength of GFRP rebars embedded in wood, and to establish bending strength and stiffness of large-scale beams reinforced with GFRP pultruded plates, and GFRP rebars. The GFRP rebars were developed to be used specifically as reinforcing materials for truss members, while the GFRP plates were developed to enhance the bending capacity of floor beams and stringers. The results showed bonded-in GFRP rebars performed very well in terms of pullout force and bond strength, and the strength and stiffness of GFRP reinforced timber beams improved significantly. Additionally, during this research several methods of concealing the reinforcement, thereby preserving the historic integrity of structural members were investigated. Dedicated to my wife Denise, without her patience, support and reassurance this would not have been possible. iii ACKNOWLEDGMENTS The author would especially like to thank Dr. Hota V. S. GangaRao who was both the author’s advisor and committee chairman. He provided too many contributions to mention; his understanding, wisdom and teachings will never be forgotten. Special thanks are also owed to the remainder of the advisory committee. The author is thankful to have had the opportunity to learn from and interact with, Dr. Emory Kemp, whose knowledge and experience in the area of preservation of covered bridges in unequaled. Samer Petro served as both an advisory committee member and as the primary investigator for the project. He provided assistance on every aspect of the project. The author would also like to thank Dr. Udaya Halable for his insightful review and serving as a committee member and also Mr. Donald Tusing and Mr. Aaron Smith for their assistance with laboratory testing throughout the course of the project. The author gratefully acknowledges the funding and support of the Federal Highway Administration and Sheila Duwadi and the Timber Bridge Research Council for their valuable review and comments. iv Table of Contents Abstract............................................................................................................................... i Acknowledgements .......................................................................................................... iii Chapter 1 – Introduction...................................................................................................1 1.1 Background..............................................................................................................1 1.2 Objectives and Scope of Work ................................................................................3 1.2.1 Objectives ....................................................................................................3 1.2.2 Scope of Work .............................................................................................4 1.3 Research Significance..............................................................................................4 Chapter 2 – Literature Review .........................................................................................5 2.1 Introduction..............................................................................................................5 2.2 Historic Covered Bridges.........................................................................................5 2.3 The Secretary of the Interior’s Standards for the Treatment of Historic Properties..................................................................7 2.4 Current Methods for Preserving Covered Bridges...................................................9 2.5 Modern Methods for Preserving Covered Bridges ................................................13 2.5.1 Externally Bonded Repair..........................................................................17 2.5.2 Philippi Covered Bridge ............................................................................18 2.5.3 Barrackville Covered Bridge .....................................................................18 Chapter 3 – Laboratory Experiments............................................................................20 3.1 Introduction............................................................................................................20 3.2 Tension Tests.........................................................................................................20 3.2.1 Introduction................................................................................................20 3.2.2 Preparation of Test Specimens...................................................................20 3.2.3 Testing Procedure......................................................................................24 3.3 Bending Tests (Small Scale)..................................................................................24 3.3.1 Introduction................................................................................................24 3.3.2 Preparation of Test Specimens...................................................................24 3.3.3 Testing Procedure......................................................................................26 3.4 Bending Test (6” x 11 ¾”) with GFRP Plates .......................................................27 3.4.1 Introduction................................................................................................27 3.4.2 Tension Tests (GFRP plates) .....................................................................27 3.4.2.1 Preparation of Test Specimens.................................................27 3.4.2.2 Testing Procedure....................................................................28 3.4.2.3 Results .....................................................................................28 3.4.3 Preparation of Full Scale Bending Test Specimen ....................................29 3.4.4 Testing Procedure......................................................................................32 3.5 Bending Tests with GFRP Reinforcing Bars.........................................................33 3.5.1 Introduction................................................................................................33 3.5.2 Preparation of Test Specimens...................................................................33 3.5.3 Testing Procedure......................................................................................38 v 3.6 Bending Test (6” x 8”) with GFRP Plates .............................................................39 3.6.1 Introduction................................................................................................39 3.6.2 Preparation of Test Specimens...................................................................39 3.6.3 Testing Procedure ......................................................................................41 3.7 Summary of Tests ..................................................................................................42 3.8 Historic Preservation..............................................................................................43 Chapter 4 – Results and Discussions..............................................................................47 4.1 Introduction............................................................................................................47