DOCSLIB.ORG

Construction Techniques for Segmental Concrete Bridges

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Construction Techniques for Segmental Concrete Bridges ••N♦N^j1♦j.•♦j^♦j-.•je♦j-♦•j1♦N♦••♦N•N♦N♦N•N♦NeeeN•N•N•N♦N•N•N♦N•♦ ♦•t Construction Techniques for Segmental Concrete Bridges •2•.i. •i• •e• .i. James M. Barker .i. Associate •Z• H. W. Lochner, Inc. Consulting Engineers Chicago, Illinois ne of the primary advantages of struction or in design in the United O segmental concrete bridge con- States, few have been or will be con- struction is the economics. In a large structed in exactly the same manner. majority of cases, segmental construc- The multitude of choices available to tion has been the winner where alternate contractors allows them to tailor each construction methods have been avail- project to their manpower and equip- able to contractors at the time of bidding. ment in the interest of maximizing effi- There are many reasons for this rela- ciency and optimizing cost. tively new method of bridge construction Segmental bridge construction is also in the United States competing so well in revising the basic thinking of design en- the 10 years since the European transfer gineers. Until recently, designers have technology was started. I believe, how- concerned themselves mainly on how to ever, that the principle reason for the build the project after preparing compu- success of segmental concrete con- tations and plans. Segmental construc- struction is the number of construction tion has revised this thinking. The first techniques available to build these question asked about a project now is bridges. Of approximately 35 to 40 such "What is the best and most economical bridges either completed, under con- way to build this project?" Once this question has been satisfactorily an- swered, the designer can proceed with a NOTE: This article is based on a presentation given design based on the most efficient con- at the Long Span Concrete Bridge Conference in Hartford, Connecticut, March 18-19, 1980. The struction method. conference was sponsored by the Federal Highway In order to make intelligent decisions, Administration, Portland Cement Association, Pre- stressed Concrete Institute, Post-Tensioning Insti- both designers and contractors need to tute, and Concrete Reinforcing Steel Institute. become familiar with the available 66 0FFIT ARRIAGE CCC e ^ ^ ^^1^i1i1^o oo oo o O Fig. 1. Schematic of short line match casting system. The usual rate of production is four segments per week per set of forms. methods of segmental construction. Not methods to be discussed utilize the con- all methods are applicable to all projects cept of match casting. The basic prem- but all should be considered for each ise of match casting is to cast the seg- job. There are several fundamental con- ments so their relative erected position cepts relating to casting and erection of is identical to their relative casting posi- segments which could be considered for tion. This requires a perfect fit between practically every bridge project. By no the ends of the segments and is accom- means should these basic concepts be plished by casting each segment directly the only ones considered. Segmental against the face of the preceding one bridge construction was born out of in- using a debonder to prevent bonding of novation and will continue to grow the concrete. The segments are then through more innovation by both con- erected in the same sequence they were tractors and design engineers. cast. The most common method for match Precasting Techniques casting segments is called the "short line" method. Fig. 1 shows a schematic Short line system—All the casting of a short line match casting system. PCI JOURNAUJuly-August 1980 67 Fig. 2. Casting machines (forms) fold back hydraulically or with screw jacks to permit moving of segments. With this system, the rate of segment When the workers arrive at the pre- production will approach one segment casting yard on Wednesday morning, per line of forms per day. A good aver- the side forms are closed, the inside age to use for a project is four segments form is rolled forward, Tuesdays seg- per line every 5 days. ment is in the new segment position and For the sake of explaining the casting Mondays segment is in the old segment procedure, assume today is Wednes- position. The first operation is to deter- day. The older segment was cast on mine the relative position as the seg- Monday and is now cured and ready for ments actually were cast. This is done the storage yard. The old segment was by shooting elevations and centerline cast yesterday or Tuesday and was with an accurate survey instrument. match cast against Mondays segment. These shots are called "early morning Today a new segment will be cast shots." (Geometry control will be dis- against Tuesdays segment. cussed in greater detail later.) Once the Fig. 2 shows the form arrangement early morning shots are taken, the forms for short line match casting. The French are released and Mondays segment is call these forms casting machines. taken to the storage yard. Tuesdays The appropriateness of this name will segment is then moved from the new soon become apparent for they really segment position to the old segment po- are machines. The length of the side sition. forms is equal to the length of the seg- All of the geometry of the bridge (hori- ment being cast plus 1 or 2 in. (25 or 51 zontal or vertical curves and super- mm) to seal around the match cast elevation or transitions) is cast in by ad- joint. The side forms have the capability justing the old segment. The forms are of being folded back away from the never adjusted for geometry. Therefore, segment to permit removal of the seg- once Tuesdays segment is in the old ment. This is done either with screw segment position, its attitude is adjusted jacks or hydraulic rams. The collapsible by screw jacks between the carriage and inside formwork which forms the void of the soffit to provide the proper bridge the box girder rolls on rails to allow re- geometry. A prefabricated reinforcing moval of the form, enabling the segment bar cage is then set in the new segment to be lifted vertically. position. Once the side forms are closed 68 Fig. 3. Casting machine. Proper geometry is obtained by adjusting the alignment of the cast-against (concrete) segment with screw jacks under the supporting soffit. and the inside form is rolled forward, the screw jacks for adjusting the attitude of casting machine is ready for casting to- the old segment. days (Wednesdays) segment. Fig. 4 is a schematic of the geometry Fig. 3 shows a casting machine for a control layout for a short line casting short line match cast system. Note the method. The survey instrument is PERMANENT PERMANENT TARGET INSTRUMENT ^ I STEEL BULKHEAD I H NEW SEGMENT 7/7,177/77/77/ 77777/77?/ PERMANENT SOFFIT Fig. 4. Geometry control layout for short line system. The instrument support and target should be stationary and permanent. PCI JOURNAUJuly-August 1980 69 nent survey control points. its are located over the ninate any influence of top rents. The center points 9oretical centerline. ally a theodilite capable of measuring Round-headed bolts placed 2 or 3 in. accurately to 1/32 of an inch (nearly 1 (51 or 76 mm) from the edge of segment mm). The permanent target is generally are used for the elevation control points. a concrete pile driven into the ground They are assumed to be at the edge of and insulated to prevent bending due to the segment for computation purposes the sun shining on one side. Elevations and should always be placed over the are shot using a survey rod. A metric rod webs to eliminate any influence of top may be more practical because the slab deflections. Since only relative po- smallest graduations are approximately sitions of segments are of concern, 1/32 of an inch which eliminates some of these bolts do not have to be placed at the guesswork involved when using rods any specific elevation but may be placed marked in feet and inches. The data in the wet concrete so the bottom of the measured are elevation differences so head is approximately at the concrete the metric rod does not result in exten- level. The early morning shots on these sive unit conversion. points establish the basis of relative po- The segment survey control point po- sitions. sitions are shown in Fig. 5. Each seg- The two centerline control points usu- ment has six control points—four over ally consist of U-shaped wires placed in the two webs and two on the centerline. the wet concrete after the top slab has ERECTED CANTILEVER FINAL PROFILE \ a THEORETICAL CASTING CURVE PIER LOCATION A = DEFLECTION DUE TO PRESTRESS Fig. 6. Theoretical casting curve is drawn from data provided by the design engineer. 70 been finished. The theoretical centerline by the erected cantilever curve in Fig. 6. is established by notching these wires Therefore, it is obvious the segments with a hammer and chisel during the must be cast with -a downward deflection early morning shots. of A so when the camber occurs the The designer of the bridge will provide proper alignment will be achieved. A information to develop a theoretical curve depicting this downward deflection casting curve. The theoretical casting is the theoretical casting curve. In reality, curve is a curve along which the seg- when all the deformations are consid- ments should be cast so the final de- ered, the theoretical casting curve usu- sired alignment will be achieved after all ally bends upward rather than down- deformations.
Load more

Recommended publications
  • An Overview of Precast Prestressed Segmental Bridges
    An Overview of Precast Prestressed ♦ Segmental Bridges Walter Podolny, Jr. Bridge Division Office of Engineering Federal Highway Administration U.S. Department of Transportation Washington, D.C. he seventies will be recorded by Construction in this manner may T engineering historians as the de- also have a serious impact upon envi- cade in which prestressed concrete ronment and ecology. Prestressed segmental bridge construction came of segmental construction has extended age in North America. Segmental box the practical span of concrete bridges girder bridges have attracted the at- to approximately 800 ft (244 m). tention and captured the imagination Where segmental construction is used of bridge engineers and designers in conjunction with the cable-stay across the continent. bridge concept, the span range can be Because of practical limitations of extended to 1300 ft (400 m) and handling and shipping, the precast perhaps longer.' prestressed I-girder type of bridge Because construction of the super- construction is limited to an approxi- structure is executed from above, i.e., mate range of 120 to 150-ft (37 to 46 at deck level, the use of extensive m) spans. Beyond this range of span, falsework is avoided. Thus, there is no post-tensioned cast-in-place box gir- effect upon navigation clearance from ders on falsework are more attractive. falsework during construction and the However, in certain instances the ex- cost of extensive formwork is elimi- tensive use of falsework can prove to nated. Segmental viaduct type bridges be an economic disadvantage. Where provide a method whereby the impact deep ravines or navigable waterways of highway construction through en- must be crossed, extensive formwork vironmentally sensitive areas can be may be impractical.
    [Show full text]
  • Bridge Engineering Handbook Superstructure Design Segmental
    This article was downloaded by: 10.3.98.104 On: 02 Oct 2021 Access details: subscription number Publisher: CRC Press Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: 5 Howick Place, London SW1P 1WG, UK Bridge Engineering Handbook Superstructure Design Wai-Fah Chen, Lian Duan Segmental Concrete Bridges Publication details https://www.routledgehandbooks.com/doi/10.1201/b16523-4 Wai-Fah Chen, Lian Duan Published online on: 24 Jan 2014 How to cite :- Wai-Fah Chen, Lian Duan. 24 Jan 2014, Segmental Concrete Bridges from: Bridge Engineering Handbook, Superstructure Design CRC Press Accessed on: 02 Oct 2021 https://www.routledgehandbooks.com/doi/10.1201/b16523-4 PLEASE SCROLL DOWN FOR DOCUMENT Full terms and conditions of use: https://www.routledgehandbooks.com/legal-notices/terms This Document PDF may be used for research, teaching and private study purposes. Any substantial or systematic reproductions, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The publisher shall not be liable for an loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. 3 Segmental Concrete Bridges 3.1 Introduction ........................................................................................91
    [Show full text]
  • Ten Years of Segmental Achievements and Projections for ~He Next Century
    Ten Years of Segmental Achievements and Projections for ~he Next Century The last 10 years have seen dramatic growth in the construction of segmental concrete bridges in North America, which is estimated to have an annual construction volume exceeding one billion dollars. The bridges have been built using both precast and cast-in-place concrete segmen..ts. Many of these projects have won national and regional awards ~ · · fhis article presents summaries of the major structural features of some of the most outstanding segmental bridges constructed in North America during the last 10 years. Clifford l. Freyermuth Details concerning the design and method of construction of each Manager project are discussed. Finally, the future prospects and potential for American Segmental Bridge Institute segmental bridge construction in the next century are addressed. Phoenix, Arizona Clifford L. Freyermuth is president rom Bangkok to Boston, the past It is estimated that since 1980, the of Clifford L. Freyermuth, Inc. , 10 years have witnessed the cost of segmental construction (pre­ which was formed in 1988 to Femergence of segmental con­ cast and cast-in-place) completed in provide structural consu lting crete bridge construction as the North America is about $5 billion. services for post-tensioned, method of choice for major transporta­ prestressed concrete buildings and Today, the annual construction vol­ bridges. The firm has provided tion projects. In the United States, this ume of this industry is around $1 bil­ management and technical serv ices result has primarily been achieved due lion and is expected to grow in the to the American Segmental Bridge to the initial cost advantages of seg­ next century.
    [Show full text]
  • ABC Applications in Segmental Bridge Construction
    FIGG Accelerated With Bridge Concrete Segmental Construction Bridges William R. (Randy) Cox, P.E. American Segmental Bridge Institute Outline • Introduction • Precast Segmental Bridges ˗ Balanced Cantilever ˗ Span-by-Span ˗ Substructure • Connections ˗ PTI/ASBI Grouted Post-Tensioning Specification • Conclusions Introduction ADVANTAGES OF CONCRETE SEGMENTAL BRIDGES • Redundancy • Overload Capacity • Insensitive to Fatigue • Fire Resistance • Deflection Control • Durability McNary Bergeron Precast Balanced Cantilever Construction Four Bears Bridge Opened September 2005 Ft. Berthold Indian Reservation, 4,500’ Bridge FIGG North Dakota 482 superstructure segments Casting yard near one end of the bridge Indoor casting facility Superstructure Precasting FIGG Prefabricated reinforcing cage Casting Operations placed in segment form FIGG Concrete placement using Casting Operations overhead crane and bucket FIGG Casting Operations Segment move to storage FIGG Segment Transport FIGG Segment Delivery FIGG Pier Table Erection FIGG Typical Segment Erection FIGG Typical Closure Joint FIGG Typical Erection of 4 to 6 segments per day (40’ - 60’) Four Bears Bridge: 10 Segments (100’) erected in 1 day maximum Entire 316’ span in 9 days Construction Rate FIGG Four Bears Bridge Ft. Berthold Indian Reservation, FIGG North Dakota Balanced Cantilever Erection Segments Can Be Erected using: • Barge-mounted cranes • Ground based cranes • Beam and Winch on cantilever end • Overhead Gantry FIGG New I-35W Bridge Opened in Sept 2008 Minneapolis, Minnesota 1,214’ long, 504’ Mainspan FIGG Superstructure Long Line Precasting Method FIGG 1 New I-35W Bridge 120 segments placed in 47 days NTP to close of main span Minneapolis, Minnesota was 9 months FIGG Victory Bridge over Raritan River Opened in 2005 Sayreville, New Jersey Twin 3,971’ Bridges FIGG Rt.
    [Show full text]
  • E Mail: [email protected]
    MIDAS Provides the best solutions in Midas Civil Structural, Geotechnical, and Mechanical Engineering Lucas Park(CAE Consultant) E mail: [email protected] MIDAS Information Technology Co., Ltd. MIDAS Information Technology Co., Ltd. www.MidasUser.com1 MIDAS Provides the best solutions in Structural, Geotechnical, and Mechanical Engineering Segmental Bridge Analysis & Design - Modeling through Wizards May.03 - Generation of numerous tendon profiles / Tapered Section / Construction Stage Sequence - Precise Analysis(Time dependent Material/Tendon Loss) High Speed Rail Road - Rail Track Analysis Model Wizard May.04 1. Automatic Modeling for a simplified separate analysis 2. Automatic Modeling for a stage analysis 3. Automatic Modeling for a moving load analysis Steel Composite Bridge Analysis & Design - Different Modeling Methods May.09 - Modifying a model from Wizard - Analysis / Design Cable Stayed Bridge Analysis - Modeling through Wizard/Modification May.11 - Auto-adjusting Cable Pretension forces - Construction Stages Suspension Bridge Analysis - Modeling through Wizard/Modification May.12 - Auto calculation of tensions in main Cables and Coordinates - Steel column design of irregular sections 2 MIDAS Information Technology Co., Ltd. www.MidasUser.com About MIDAS Company Size Established 540Engineers 1989 MIDAS Provides the best solutions in Midas Civil Structural, Geotechnical, and Mechanical Engineering World wide existence Russia Lithuania (Moscow) UK Shenyang (London) Slovenia Greece China (Beijing) Korea USA Spain (Seoul) (New
    [Show full text]
  • Segmental Bridge Construction in Florida — a Review and Perspective
    Special Report Segmental Bridge Construction in Florida — A Review and Perspective by Alan J. Moreton, P.E. State Structures Engineer Florida Department of Transportation Tallahassee, Florida 36 SYNOPSIS This paper offers an overview of the precast concrete segmental bridges designed and built in the state of Florida during the last ten years. The article summarizes various statistical structural parameters, segment manufacturing and erection methods, construction times, costs, and reviews problems typically encountered. Also included is a discussion of current industry and nationwide design and construction practices and some suggestions for possible improvements. CONTENTS Synopsis............................................37 1. Introduction ......................................38 2. Precast Segmental Bridges ........................38 3. Florida's Segmental Bridges .......................44 4. Structural Parametrics .............................44 5. Casting Yard Operations ...........................48 6. Rejected Segments .............................. 49 7. Erection Operations ...............................50 8. Some Typical Problems ...........................52 9. Time ............................................55 10. Costs ...........................................57 11. Administration Processes — Design, Construction andShop Drawings ...............................60 12. Actions by the Florida Department of Transportation ...63 13. Benefits of Segmental Bridges ......................64 14. Summary ........................................65
    [Show full text]
  • Precast Concrete Segmental Bridges America's Beautiful and Affordable
    HISTORICAL-TECHNICAL SERIES Precast Concrete Segmental Bridges America’s Beautiful and Affordable Icons How did precast concrete segmental construction become a major player in the modern American bridge industry? While the continuing growth in market share for precast, prestressed concrete systems can be attributed to numerous competitive advantages, this article presents an overview of the proliferation of segmental bridges in the United States based primarily on five advantages — economy, construction efficiency, durability, design innovation and aesthetics. Linda Figg President and Director of Bridge Art a bridge type that would be many other countries throughout the FIGG Engineering Group come an increasingly popular world. Typically, the precast, pre Tallahassee, Florida Forand successful competitor over stressed concrete bridge also proves to alternative building systems, precast be the most cost-effective alternative concrete made a rather unpretentious for owners, particularly when life- debut in the United States. Indeed, one cycle costs such as maintenance and wonders if the engineers who de repair are taken into account. signed and built America’s first pre cast concrete segmental box girder EVOLUTION OF bridge in 1973 — the John F. Kennedy PRECAST CONCRETE Memorial Causeway Bridge connect ing Corpus Christi and Padre Island, SEGMENTAL BRIDGES Texas — could have imagined that this The European Experience simple, unadomed structure would be Originating in Europe, this versatile the harbinger of some of the nation’s and economical
    [Show full text]
  • Bridge Design Basics
    Outline • BOBS Organization Structure • Bridge Type and Composition/Terminology • Asset Management • Bridge Maintenance • Bridge Design Process • Bridge Plans • Road and Bridge Coordination • Request for Action (RFA) Projects • Design in Construction • Accelerated Bridge Construction (ABC) • Wrap up 1 Bridge Design Basics Bridge Terminology Bridge Types 2 1 Bridge Terminology and Types BRIDGE TERMINOLOGY & TYPES OF BRIDGES COMPONENTS 3 Terminology FHWA A305-4 A bridge is defined in section 650.305 as "A structure including supports erected over a depression or an obstruction, such as water, a highway, or railway, and having a track or passageway for carrying traffic or other moving loads, and having an opening measured along the center of the roadway What is a bridge? of more than 20 feet between under copings of abutments or spring lines of arches, or extreme ends of openings for multiple boxes; it may also include multiple pipes, where the clear distance between openings is less than half of the smaller contiguous opening." 4 2 Bridge Terminology 5 Superstructure Bridge Deck 6 3 Superstructure Section thru sleeper Slab and sliding slab Plan view bridge deck and approaches 7 Superstructure - Barriers Type 4 Barrier Type 5 Barrier 8 4 Superstructure - Barriers Single Slope Barrier Type 6 Barrier 9 Superstructure - Railings Aesthetic Parapet Tube Railing 10 5 Superstructure - Railings 4 Tube Railing 11 Superstructure - Railings 2 Tube Railing 12 6 Superstructure Steel Girders and Welded Plate Girders Beams Rolled Shapes Concrete
    [Show full text]
  • Toll Bridge Seismic Safety Retrofit Report for the Legislature and Governor
    Toll Bridge Seismic Retrofit Program TOLL BRIDGE SEISMIC RETROFIT PROGRAM Purpose The purpose of this report is to inform the Legislature that the Toll Bridge Seismic Retrofit Program (Program) has a budget shortfall and to provide background regarding the increased costs for the San Francisco-Oakland Bay Bridge East Span (East Span) replacement. Increased costs have been driven by several factors and complications, including: time delays related to selection of a signature bridge self-anchored suspension (SAS) span and the construction complexity of the SAS; insufficient initial analyses of costs; and external global cost escalation factors. The engineering design and cost estimates have been developed in consultation with respected outside experts. Bids received on the two major East Span contracts advertised since the passage of AB1171 (Dutra, Chapter 907, Statutes of 2001) have been significantly higher than the estimated costs for these contracts. A funding solution is needed to continue the Program and complete the needed seismic safety projects of the two remaining critical bridges in the Program (Richmond-San Rafael and San Francisco-Oakland Bay Bridges). In addition to funding, timing is an issue for new legislation. The Department of Transportation (Department) recommends that the new legislation be enacted during this session for the following reasons: • The Department received a single bid for the Self-Anchored Suspension Bridge. That bid is set to expire on September 30, 2004. Legislation is needed to supplement the Program budget in order to continue the toll seismic retrofit effort and for the Department to award this bid. The contract cannot be awarded without legislative authority to expend the needed funds.
    [Show full text]
  • Modern Techniques in Bridge Engineering Techniques in Bridge Modern
    Edited by Mahmoud Modern in Bridge Techniques Engineering Due to signifi cant economic growth in the last few decades, increasing traffi c loads impose tremendous demand on bridge structures. This coupled with ongoing deterioration of bridges; introduce a unique challenge to bridge engineers in maintaining service of these infrastructure assets without disruption to vital economic and social activities. This requires innovative solutions and optimized methodologies to achieve safe and effi cient operation of bridge structures. Bridge engineering practitioners, researchers, owners, and contractors from all over the world presented on modern techniques in design, inspection, monitoring and rehabilitation of bridge structures, at the Sixth New York City Bridge Conference; held in New York City on July 25-26, 2011. This book contains select number of papers presented at the conference. This group of papers is state-of-the-art in bridge engineering and is of interest to any reader in the fi eld. Modern Techniques in Bridge Engineering Edited by Khaled M. Mahmoud an informa business MODERN TECHNIQUES IN BRIDGE ENGINEERING NY BRIDGE.indb i 6/20/2011 9:06:32 PM This page intentionally left blank Modern Techniques in Bridge Engineering Editor Khaled M. Mahmoud Bridge Technology Consulting (BTC), New York City, USA NY BRIDGE.indb iii 6/20/2011 9:06:33 PM CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2011 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Version Date: 20111129 International Standard Book Number-13: 978-0-203-18189-8 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources.
    [Show full text]
  • Gerald Desmond Bridge Long Beach, California
    THE CONCRETE BRIDGE MAGAZINE SPRING 2019 www.aspirebridge.org Gerald Desmond Bridge Long Beach, California MARYLAND ROUTE 195 (CARROLL AVENUE) BRIDGE OVER SLIGO CREEK Tacoma Park, Maryland NORTHWEST CORRIDOR EXPRESS LANES Marietta, Georgia BROTHERHOOD BRIDGE (MENDENHALL RIVER BRIDGE) Juneau, Alaska Permit No. 567 No. Permit Lebanon Junction, KY Junction, Lebanon SARAH MILDRED LONG BRIDGE Postage Paid Postage Presorted Standard Presorted Portsmouth, New Hampshire, and Kittery, Maine CONTENTS 6 Features Changing Perceptions 6 DYWIDAG-Systems International’s new high-tech inspection and monitoring tools add to its selection of post-tensioning products and services, enhancing its role as a specialty contractor. Carroll Avenue Bridge Over Sligo Creek 12 Northwest Corridor Express Lanes 16 Brotherhood Bridge Over the Mendenhall River 20 Sarah Mildred Long Bridge 24 Photo: DSI. Departments Editorial 2 12 Concrete Calendar 4 Perspective—Quantitative Assessment of Resilience and Sustainability 10 Aesthetics Commentary 27 Concrete Bridge Technology—Observations from 30 Years of Inspecting Post-Tensioned Structures 28 Concrete Bridge Technology—Seismic Behavior of Reinforced-Concrete-Filled Steel Tubes 32 Concrete Bridge Technology—Sarah Mildred Long Bridge Tower Foundation Construction 34 Photo: Johnson, Mirmiran & Thompson. Concrete Bridge Technology—Implementation of an Electrically Isolated Tendon Post-Tensioning System in the United States 36 24 Concrete Bridge Technology—Sweep in Precast, Prestressed Concrete Bridge Girders 38 Safety and Serviceability— Managing Structures Affected by Delayed Ettringite Formation and Alkali-Silica Reaction 42 FHWA—Advancing Bridge Repair and Preservation Using Ultra-High-Performance Concrete 45 State—Alabama 47 LRFD—AASHTO LRFD Bridge Design Specifications: Service IV Load Combination 51 This issue’s Concrete Connections will DSI.
    [Show full text]
  • Bridge Anatomy
    Bridge Maintenance Course Series Reference Manual Chapter 3 – Table of Contents Chapter 3 - Bridge Anatomy ...................................................................................................... 3-1 3.1 Bridge Components and Elements ........................................................................................ 3-1 3.1.1 Introduction ................................................................................................................. 3-1 3.1.2 Bridge Deck and Related Elements.............................................................................. 3-1 3.1.2.1 Structural Deck/Slab .......................................................................................................... 3-1 3.1.2.2 Wearing Surface ................................................................................................................. 3-2 3.1.2.3 Approach Slabs ................................................................................................................... 3-3 3.1.2.4 Joints .................................................................................................................................. 3-4 3.1.2.5 Curbs and Sidewalks .......................................................................................................... 3-5 3.1.2.6 Railing and Safety Features ................................................................................................ 3-6 3.1.2.7 Drainage ............................................................................................................................
    [Show full text]