Precast/Prestressed Bridges LIVE14BRID100

Precast/Prestressed Bridges LIVE14BRID100
Hello. I'm ___________ from ___________, and I'm here today to talk with you about designing bridges with precast/prestressed concrete. My presentation was developed in conjunction with the Precast/Prestressed Concrete Institute or PCI. This organization represents precast producers in North America and certifies plants that meet strict quality standards. Provider # G123 BRIDGES -section 5 -- revised

AIA/CES Quality Statement
This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to constitute approval, sponsorship or endorsement by the AIA of any method, product, service, enterprise or organization. The statements expressed by speakers, panelists, and other participants reflect their own views and do not necessarily reflect the views or positions of The American Institute of Architects or of AIA components, or those of their respective officers, directors, members, employees, or other organizations, groups or individuals associated with them. Questions related to specific products, publications, and services may be addressed at the conclusion of this presentation. Purpose: required slide by AIA for architects [This slide must be inserted as Slide #2 in your presentation. It may not contain any logos other than the AIA/CES logo on the bottom right. Do NOT change this slide. You do NOT need to read it, just simply leave it up for a few moments.] “This course is registered for the AIA for 1 Learning Unit (L.U.)”

NCEES Registered Program
PCI has met the standards and requirements of the Registered Continuing Education Program (RCEP) of the National Council of Examiners for Engineers & Surveyors (NCEES). Credit earned on completion of this program will be reported to RCEP. A certificate of completion will be issued to each participant. As such, it does not include content that may be deemed or construed to be an approval or endorsement by NCEES or RCEP. Purpose: required for NCEES credit for engineers [This slide must be inserted as Slide #3 in your presentation. It may not contain any logos other than the NCEES logo on the bottom right. Do NOT change this slide. You do NOT need to read it, just simply leave it up for a few moments.] “PCI has also met the standards and requirements of the Registered Continuing Education Program (RCEP) of the National Council of Examiners for Engineers & Surveyors (NCEES). Credit earned on completion of this program will be reported to RCEP. A certificate of completion will be issued to each participant. As such, it does not include content that may be deemed or construed to be an approval or endorsement by NCEES or RCEP. You will earn 1.0 Professional Development Hour for attending this session.”

Course Description In this program, owners and designers will learn about the low initial cost, low maintenance requirements, and long life expectancy of prestressed concrete bridges. Precast bridges have also proven to be high in long-term durability and fire resistance and have excellent riding characteristics.

Learning Objectives After participating in this program, you will be able to: Appreciate the growth in the demand for prestressed concrete bridges Explain the advantages of using prestressed bridges Differentiate non-precast bridges from totally precast bridges Consider the low cost, low maintenance requirements, and long life expectancy of prestressed concrete bridges when choosing design materials Read through learning objectives with students. BRIDGES -section 5 -- revised

Growth in the Demand for Prestressed Concrete Bridges
CLICK AND LEARN … Growth in the Demand for Prestressed Concrete Bridges Advantages of Prestressed Bridges -- Case Studies Totally Precast Bridges -- Case Studies Note to presenter: The slides in this presentation have the narrative on them. Feel free to elaborate on any specifics about each project (if you have any). There will be no notes section after this slide. The Future FORWARD BRIDGES -section 5 -- revised

Growth in the Demand for Prestressed Concrete Bridges
CLICK AND LEARN … Growth in the Demand for Prestressed Concrete Bridges MAIN FORWARD

GROWTH IN THE DEMAND FOR PRESTRESSED CONCRETE BRIDGES
The single most important event that led to the dramatic launch of the precast prestressed concrete industry in North America was the construction of the technically innovative, historically fascinating Walnut Lane Memorial Bridge in Fairmont Park in Philadelphia, Pennsylvania in and 1950. MAIN BACK FORWARD BRIDGES -section 5 -- revised

At that time, manufacturers had no experience with linear prestressing, and little published information was available. This prestressed concrete bridge became a reality because of the vision, persistence and courage of a few extraordinary individuals. MAIN BACK FORWARD

One was Professor Gustav Mangel from the University of Ghent in Belgium. He described the concept of pre- compressed concrete to his students using his well-known illustration of a stack of books. MAIN BACK FORWARD

The books on the bottom are like pre-compressed concrete: using a compressive force, they support their own weight… plus significant superimposed loads, represented by the books on top. MAIN BACK FORWARD

The combination of high strength steel – to resist tensile stress – and concrete – to provide compressive strength and durability – make this composite material adaptable to many situations, especially the design and construction of bridges. MAIN BACK FORWARD

A number of technological innovations followed the success of the Walnut Lane Bridge, including the establishment of precasting plants and in-plant pretensioning… MAIN BACK FORWARD

… and the development of 7- wire strand to replace individual wires.
GROWTH IN THE DEMAND FOR PRESTRESSED CONCRETE BRIDGES … and the development of 7- wire strand to replace individual wires. MAIN BACK FORWARD

Long-Line Casting Beds Permanent Steel Forms Admixtures
GROWTH IN THE DEMAND FOR PRESTRESSED CONCRETE BRIDGES Other early innovations included long-line casting beds; high- quality, permanent steel forms; specialized chemical admixtures; high early-strength concrete; accelerated curing with heat; and more. Long-Line Casting Beds Permanent Steel Forms Admixtures High Early-Strength Concrete Accelerated Curing MAIN BACK FORWARD

These developments received technical and logistical support from the Prestressed Concrete Institute, PCI, chartered in From the start, PCI served as a forum for precasters and design professionals, thus spurring the rapid growth of the entire precast and prestressed concrete industry. MAIN BACK FORWARD

Continuous growth in the use of precast, prestressed products has led to new designs and applications in bridges… and many other impressive structures. MAIN BACK FORWARD

PCI Certified Quality MAIN BACK FORWARD
GROWTH IN THE DEMAND FOR PRESTRESSED CONCRETE BRIDGES PCI Certified Quality PCI’s Plant Certification program quickly became an integral part of plant operations because, from the very beginning, the industry recognized the need for quality above all else. As a result, precast, prestressed concrete products have an excellent reputation for quality and are equated with state-of-the-art engineering standards and techniques. PCI Plant Certification assures specifiers that a manufacturing plant has been audited for its capability to produce quality products on an ongoing basis. MAIN BACK FORWARD

Total Bridges Built 1950 - Present
GROWTH IN THE DEMAND FOR PRESTRESSED CONCRETE BRIDGES Total Bridges Built Present The growth in the demand for prestressed concrete bridges has been nothing short of remarkable. Since 1950, some 108,000 prestressed concrete bridges have been built. This represents 30% of all bridges built during the period. 30% 108,000 Prestressed Bridges MAIN BACK FORWARD

Bridge Construction 1990 - 1999 Prestressed Concrete:
GROWTH IN THE DEMAND FOR PRESTRESSED CONCRETE BRIDGES Bridge Construction From 1990 through 1999, more than 48% of all bridges built have used prestressed concrete. Even more notable, prestressed construction represents 60% of all state highway bridges and 62% of bridges on numbered U.S. highways. Prestressed Concrete: 48% of all bridges 60% of state highway bridges 62% of numbered highway bridges MAIN BACK FORWARD

Deck Surface Area 1990 - 1999 Prestressed Concrete:
GROWTH IN THE DEMAND FOR PRESTRESSED CONCRETE BRIDGES Deck Surface Area Now, consider the deck surface area of bridges built from through % of the area of bridge decks were built on prestressed concrete superstructures. A further breakdown of deck area built on prestressed concrete superstructures shows 62% of bridges on city streets, 53% of county highway bridges, 55% of interstate highway bridges, 66% of bridges on state highways, and 59% on U.S. numbered highways. Prestressed Concrete: 60% of deck area of all bridges 62% of area of city bridges 53% of area of county bridges 55% of area of interstate bridges 59% of area of U.S. numbered bridges MAIN

Advantages of Prestressed Concrete Bridges --
CLICK AND LEARN … Advantages of Prestressed Concrete Bridges -- Case Studies MAIN FORWARD

Bridges Built MAIN BACK FORWARD
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Bridges Built Owners and designers have long recognized the low initial cost, low maintenance needs and long life expectancy of prestressed concrete bridges. This is reflected in the increasing market share of prestressed concrete, which has grown from zero in to more than 55 percent today. % Built 60 P/C 50 40 30 S/S 20 R/C 10 T 50 55 60 65 70 75 80 85 90 95 00 Year Built Source: National Bridge Inventory Data MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
This growth continues very rapidly, not only for bridges in the short span range, but also for spans in excess of 150 feet which, heretofore, has been nearly the exclusive domain of structural steel. MAIN BACK FORWARD

Structural/Engineering
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES The following examples illustrate some of these key advantages of precast, prestressed concrete bridges: Cost Efficiencies Structural/Engineering Design Aesthetics PCI Certified Quality MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Many bridge designers are surprised to learn that precast, prestressed concrete bridges are usually lower in first cost than all other types of bridges. Coupled with savings in maintenance, precast bridges offer maximum economy. Cost Efficiencies Structural/Engineering Design Aesthetics PCI Certified Quality MAIN BACK FORWARD

Fast and Easy Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction An old bridge located on a main logging road in Idaho was replaced with a prestressed concrete bridge. The bridge consists of integral deck beams on precast concrete abutments and wing walls. The heavy spring runoff dictated the need for a shallow superstructure, and the load capacity of the bridge had to be sufficient to carry off- highway logging trucks that weigh as much as 110 tons each. Fast and Easy Construction MAIN BACK FORWARD

Cost Efficiencies and Speed of Construction MAIN BACK FORWARD
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction The precast prestressed bridge system offered two principal advantages: it was economical and it provided minimum downtime for construction. Project duration was three weeks. MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction The state of Minnesota saved more than 16% - a half a million dollars – by planning for a prestressed alternate to a steel bridge. The 700-foot-long bridge is jointless up to the abutments and is the longest continuous bridge in the state. It also contains the longest single concrete span. MAIN BACK FORWARD

Cost Efficiencies and Speed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction A Minnesota transportation official stated, “Originally, we didn’t think concrete was suited to this… bridge. However, the fabricator showed us it was a viable alternative. Everything went smoothly… we’re well satisfied…” MAIN BACK FORWARD

Easy to Erect Cost Efficiencies and Speed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction Precast, prestressed concrete bridge components are easy to erect, particularly when the tops of the units comprise the entire deck slab to form an “integral deck” or “full-deck” beam. Easy to Erect MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction In a full-deck bridge, the formwork of the superstructure is eliminated. Connections between adjacent units often consist of welding matching plates and grouting continuous keyways. Carefully planned details speed the construction process and result in overall economy. MAIN BACK FORWARD

Cost Efficiencies and Speed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction Substandard bridges are easily replaced with precast prestressed sections. In some cases, existing abutments can be used… MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction …but it may be easier and more economical to build new ones, or to utilize precast abutments and wing walls supported on cast-in-place footings. Because precast concrete integral deck bridges with precast abutments can be erected without delay in cold weather, they can be opened to traffic sooner. MAIN BACK FORWARD

Fast Construction Cost Efficiencies and Speed of Construction MAIN
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction Bridge departments are challenged to maintain traffic flow, minimize traffic interruptions, and reduce or eliminate detours during construction projects. This Florida bridge, damaged in a tanker fire, was completely rebuilt and opened to traffic in 18 days. Fast Construction MAIN BACK FORWARD

Fast Construction All Seasons
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction The fast construction of precast concrete integral deck bridges is a key advantage. Precast concrete bridges can be installed during all seasons and opened to traffic more rapidly than any other permanent type of bridge, because of the availability of plant-produced sections and the speed of erecting and finishing construction. Fast Construction All Seasons MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction Replacing this bridge on US Route 95 in Idaho illustrates another example of the advantages of very fast construction: New Year’s Day: Rains and melting snow washed out this bridge over the Little Salmon River linking the northern and southern parts of the state. Fast Construction MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES January 4: The Idaho Department of Transportation contacted the precaster to investigate solutions. They determined that the fastest way to replace the three spans was to use a single 80-foot span comprised of bulb-tees with an integral deck. The top flange would be 8-inches thick and 8'-6" wide. The end diaphragms would also be precast onto the girder ends. January 8: Engineers in the Bridge Section approved shop drawings and tensioning calculations. Cost Efficiencies and Speed of Construction Fast Construction MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction January 18: Bulb-tees were shipped 240 miles and set in place…just 17 days after the flood! Included in the shipment was intermediate steel diaphragms, guard rail posts and guard rail…all the components to complete the structure. January 25: The project was completed. The bridge was in service just 24 days after the flood! Fast Construction MAIN BACK FORWARD

Simple Solution Cost Efficiencies and Speed of Construction MAIN BACK
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction As a result of a Winter flood, this single lane bridge on a major forest road was washed out, cutting access to a U.S. highway for a half dozen residents…including one with a senior needing continuing medical care. Within only 15 of receiving plans, the precaster had fabricated the 135-foot-long spans with 7’-6”-wide integral decks, and the bridge was opened to traffic 3 days later – 18 days in all. Simple Solution MAIN BACK FORWARD

Adverse Weather Conditions Cost Efficiencies and Speed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction In Ketchikan, Alaska a bridge on the only highway to the north was washed out when an old dam gave way on October Integral deck girders were selected for the 85-ft span. The 12 girders were designed and precast in the state of Washington, then shipped by rail and barge to Alaska. The girders were installed and the bridge was completed and opened to traffic on December 19 - only 54 days after the washout - despite the problems of design, remote location, great distances, and adverse weather conditions during the onset of an Alaskan winter! Adverse Weather Conditions MAIN BACK FORWARD

Total Operating Costs (Maintenance)
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction To accurately compare costs, consider a bridge’s life-cycle: The initial cost of the structure must be added to the total operating cost. For stationary bridges, the operating cost is the maintenance cost. Life Cycle Cost = Initial Structure + Total Operating Costs (Maintenance) MAIN BACK FORWARD

Durable Cost Efficiencies and Speed of Construction MAIN BACK FORWARD
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction The durability of precast prestressed concrete bridges designed and built in accordance with AASHTO or AREMA specifications means there should be little, if any need for maintenance. One of the reasons designers select integral deck prestressed concrete is the durability of the precast, prestressed concrete and the resulting low maintenance requirements. Durable MAIN BACK FORWARD

Durable Cost Efficiencies and Speed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction Fatigue problems are nonexistent because only minor net stresses are induced by traffic loads. Durable MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction And of course, no painting is needed. Some bridge engineers estimate the life-cycle cost of re- painting steel bridges to be 15 to 25% of the initial cost. Painting bridges is environmentally unfriendly and can be especially dangerous or expensive when done over busy highways, streams, railroad rights- of-way or in rugged terrain. Painting Steel Bridge MAIN BACK FORWARD

Minimal Maintenance Cost Efficiencies and Speed of Construction MAIN
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Cost Efficiencies and Speed of Construction On the Illinois Toll Highway, the superstructures of 224 bridges are precast prestressed concrete beams. These bridges, built during 1957 and 1958, have withstood heavy traffic and severe weathering and yet require very little maintenance. Other projects in all parts of North America have exhibited similar experience ‑ little or no maintenance has been required on precast prestressed concrete bridges. Minimal Maintenance MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES In addition to its cost efficiencies and speed of construction, precast concrete provides important structural and engineering advantages as well. Cost Efficiencies Structural/Engineering Design Aesthetics PCI Certified Quality MAIN BACK FORWARD

Shallow Superstructure
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages A common requirement of many bridges is that the superstructure be as shallow as possible in order to provide maximum clearance with minimum approach grades. Through the technique of prestressing, the designer can utilize the maximum possible span-to-depth ratio. This superstructure occupies just 13 inches of profile. Shallow Superstructure MAIN BACK FORWARD

Shallow Superstructure
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages Span-to-depth ratios as high as 30:1 can be achieved with solid slabs, voided slabs, box beams, multi-stemmed units, or bulb-tee sections. Even though deeper sections will require less prestressing steel, the overall economy of a project may dictate the highest possible span-to- depth ratio. These HPC girders are 4'-6" deep and span 157 ft. A span/depth ratio of nearly 35! Shallow Superstructure MAIN BACK FORWARD

Adaptable to Many Situations
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages Precast prestressed concrete integral deck girders were selected to provide a shallow superstructure for a bridge over a busy urban highway in Denver. Even though the bridge must carry frequent heavy truck traffic, the total depth of the girders is only 3 feet, including the 3- inch wearing surface, for a span of 80 feet. Adaptable to Many Situations MAIN BACK FORWARD

High Span-to-Depth Ratio
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages This bridge illustrates the high span-to- depth ratios possible with integral deck prestressed concrete. High Span-to-Depth Ratio MAIN BACK FORWARD

Structural/Engineering Advantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages Bridges are subjected to an assortment of hostile environments as well as repeated impact loadings. Some must endure intense sun, extreme temperatures and brackish waters. Others must withstand not only the freezing and thawing provided by nature but also the potential for damage through the use of de-icer chemicals. Dense, high strength prestressed concrete has excellent freeze-thaw and chemical resistance. MAIN BACK FORWARD

Fire Resistance Structural/Engineering Advantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages Greater fire resistance is another advantage. This timber bridge experienced a dramatic fire… Fire Resistance MAIN BACK FORWARD

Structural/Engineering Advantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages …it was replaced by a low maintenance prestressed concrete bridge erected without falsework over an environmentally- sensitive area… MAIN BACK FORWARD

Excellent Riding Characteristics
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages Prestressed concrete bridges have excellent riding characteristics that minimize traffic vibrations. The public will not only be safe but also feel secure and comfortable on a prestressed concrete bridge. Traffic vibrations are held to an absolute minimum. The owner will have a structure on which the deck is less likely to crack prematurely. Continuous spans even hold deck joints to a smooth minimum. Excellent Riding Characteristics MAIN BACK FORWARD

Excellent Riding Characteristics
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Structural/Engineering Advantages Steel girder bridges frequently exhibit noticeable vibrations. The natural frequency of vibration of these bridges often coincides with the frequencies of traffic and then resonance occurs. Because of their mass and stiffness, the natural frequency of vibration of prestressed girder bridges rarely coincides with the vehicle frequencies. Documented cases show that light bulbs in fixtures installed on steel bridges burn out more rapidly as a result of such vibrations. Reports are surfacing that indicate decks on steel bridges are more prone to cracking and deterioration. Excellent Riding Characteristics MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES The clean, attractive lines of concrete beams also help bridge designers meet the most demanding aesthetic requirements. Cost Efficiencies Structural/Engineering Design Aesthetics PCI Certified Quality MAIN BACK FORWARD

Design Aesthetics MAIN BACK FORWARD
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Design Aesthetics Prestressed concrete bridges can be attractive from above, below, and from the side because of the simple and clean shapes of the members used. The high span-to- depth ratios made possible through the use of prestressing, result in strong, tough, durable and yet graceful bridges. MAIN BACK FORWARD

ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES Prestressed concrete is efficient because it is a composite of high- strength steel and high-performance concrete. To ensure this efficiency and to comply with exacting project specifications, precasting plants have developed sophisticated quality assurance programs. Cost Efficiencies Structural/Engineering Design Aesthetics PCI Certified Quality MAIN BACK FORWARD

PCI Certified Quality Precast, prestressed concrete products are inspected both during and following production. In fact, every operation in the manufacturing process provides a point of inspection and control. MAIN BACK FORWARD

PCI Certified Quality Today’s bridge designs use more high- performance materials and sophisticated solutions than ever before. More and more, engineers are requiring only qualified sources with certified technicians and inspectors. MAIN BACK FORWARD

Independent Auditors; Unannounced Audits
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES PCI Certified Quality A plant that is PCI-certified tells the engineer five important things: The production facility has demonstrated its capability to produce quality products to the satisfaction of a nationally recognized, independent consulting engineering and inspection firm engaged by PCI for multiple, unannounced annual audits. The rigid audits the plant undergoes are based on published industry standards – the PCI Manual for Quality Control for Plants and Production of Precast Structural Concrete. Independent Auditors; Unannounced Audits Audits Based on National Standards MAIN BACK FORWARD

Independent Auditors; Unannounced Audits
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES PCI Certified Quality Independent Auditors; Unannounced Audits Five important things cont.: 3. The plant practices a documented and PCI- approved quality assurance program open for review. 4. The plant has PCI-certified QC personnel. 5. The producer has PCI confirmed capabilities. Audits Based on National Standards Documented Quality System Certified Personnel Confirmed Capabilities MAIN BACK FORWARD BRIDGES -section 5 -- revised

PCI Certified Quality MAIN
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES PCI Certified Quality To maintain PCI Certification, producers are audited and graded semi-annually on more than 150 items that include an inspection of all raw materials; concrete mixing, placing, finishing and curing; tensioning and de- tensioning of strands; temperature controls; stripping, stockpiling and inspection of product. In addition, engineering, shop drawings, record keeping, purchasing, personnel training, and many other practices related to quality production are examined. Failure to maintain acceptable standards makes loss of certification mandatory. MAIN

Totally Precast Concrete Bridges --
CLICK AND LEARN … Totally Precast Concrete Bridges -- Case Studies MAIN FORWARD

MAIN BACK FORWARD TOTALLY PRECAST BRIDGES -- CASE STUDIES
Is it possible to design an “Instant Bridge?” Almost! There are many ways to put a bridge together quickly with precast concrete products. The speed and variety of precast prestressed products and methods give designers many options. Consider these advantages of an all-precast bridge… MAIN BACK FORWARD

Benefits to Owner Agencies:
TOTALLY PRECAST BRIDGES -- CASE STUDIES Fast construction benefits owner agencies by reducing the duration of the work zone. Fast construction reduces traffic handling costs and accident exposure risks. There’s less inconvenience to the traveling public, fewer delays, and fewer motorist complaints. According to a report by the Texas Transportation Institute, costs incurred by drivers passing through a work zone (along with engineering costs) can be $10,000 to $20,000 per day. A recent Federal report indicates user costs of $50,000 per day for work zones in urban areas. Benefits to Owner Agencies: Reduction in the duration of work zones Reduced traffic handling costs Reduced accident exposure risks Less inconvenience to the traveling public Fewer motorist complaints MAIN BACK FORWARD

Benefits to Contractors:
TOTALLY PRECAST BRIDGES -- CASE STUDIES Contractors benefit from reduced exposure to traffic hazards. More work can be accomplished in less time, with fewer weather delays. Costs are lower for forms, skilled field labor, scaffolding and shoring, and cranes. Benefits to Contractors: Reduced exposure to hazards More work -- less time Fewer weather delays Lower costs Less skilled labor MAIN BACK FORWARD

TOTALLY PRECAST BRIDGES -- CASE STUDIES
After foundations have been completed, scheduling can be controlled by a single contractor working with a familiar material. Scheduling Control MAIN BACK FORWARD

Plant-produced Elements
TOTALLY PRECAST BRIDGES -- CASE STUDIES Precast concrete structural elements should always be plant produced under carefully controlled conditions…by plants that are Certified by PCI. Plant-produced Elements MAIN BACK FORWARD

Quality and Corrosion Resistance
TOTALLY PRECAST BRIDGES -- CASE STUDIES … so all structural elements benefit from the excellent quality and corrosion resistance of prestressed concrete. Quality and Corrosion Resistance MAIN BACK FORWARD

Fully-cured precast concrete structural elements can be stockpiled in advance of need… Stockpiled in Advance MAIN BACK FORWARD

Immediate Delivery and Erection
TOTALLY PRECAST BRIDGES -- CASE STUDIES …and can be scheduled for “just- in-time” delivery and erection… Immediate Delivery and Erection MAIN BACK FORWARD

There’s no curing time required at the jobsite, as with cast-in-place concrete. Bridge piers can be erected in a day, and beams can follow immediately. No Curing Time MAIN BACK FORWARD

The following photos illustrate the many products and construction methods that enable very rapid project completion. In addition to the often-used superstructure elements of girders and deck slabs, substructure components such as these piers can also be precast. MAIN BACK FORWARD

Precast concrete piles are quite popular in much of the country. They come in different sizes and shapes, ranging from 10- inch square piles to 66-inch diameter hollow cylinder piles. MAIN BACK FORWARD

Pile caps also can be precast concrete, reducing exposure, forming and curing in the field. MAIN BACK FORWARD

Piers can be made of precast concrete pieces quickly assembled in the field. MAIN BACK FORWARD

Abutments can also be made of precast.
TOTALLY PRECAST BRIDGES -- CASE STUDIES Abutments can also be made of precast. MAIN BACK FORWARD BRIDGES -section 5 -- revised

Sucker Creek Bridge in Hague
TOTALLY PRECAST BRIDGES -- CASE STUDIES The Sucker Creek Bridge in Hague, New York, consists of precast concrete box beams supported on precast concrete abutments assembled into a jointless, rigid frame. Sucker Creek Bridge in Hague MAIN BACK FORWARD

In San Juan, Puerto Rico, the totally precast concrete Baldorioty de Castro Avenue bridges were built in record-setting time, attractively, and economically. Puerto Rico MAIN BACK FORWARD

A totally precast bridge
TOTALLY PRECAST BRIDGES -- CASE STUDIES Each of four bridges, ranging in length from 700 to 900 feet, was erected in about 24 hours. This was well within the owner’s construction allowance of 72 hours per bridge, a condition established to minimize disruption to one of the city’s highly traveled corridors. Puerto Rico - A totally precast bridge MAIN BACK FORWARD BRIDGES -section 5 -- revised

In addition to speed, the bridges also met the city’s budgetary needs. The four box-beam bridges were constructed for $2 million less than the next lowest bid for another material. Puerto Rico MAIN BACK FORWARD

Confederation Bridge New Brunswick, Canada
TOTALLY PRECAST BRIDGES -- CASE STUDIES Totally precast bridge systems may be the only viable solution in harsh field conditions. The Confederation Bridge connecting Canada’s Prince Edward Island to mainland New Brunswick is such an example. The bridge spanned the eight- mile-wide Northumberland strait, which experiences severe winters and is covered with ice floes for five months of the year. Confederation Bridge New Brunswick, Canada MAIN BACK FORWARD

Even in such harsh conditions, precast concrete was able to meet the owner’s requirements of a year service life, a 3½-year construction period, and attractiveness. Confederation Bridge MAIN BACK FORWARD

It just makes economic sense to evaluate conversion of cast- in-place to precast concrete. This was done for the Edison Bridge in Florida. Precast piers and beams were spliced to produce tall pier bents. Edison Bridge Florida MAIN BACK FORWARD

The state of Texas has constructed several bridges with segmental precast concrete piers. The attractive piers and pier caps are hollow members. Some are made of high- performance concrete. Such segments may be match-cast, similar to segmental box girder bridges, or separated by a thin mortar bed, much like giant masonry units. Texas - Precast Piers MAIN BACK FORWARD

Louetta Road Bridge Texas
TOTALLY PRECAST BRIDGES -- CASE STUDIES In Houston, the Louetta Road Overpass utilized precast concrete match- cast piers, as well as precast, prestressed U- beams and stay-in- place deck panels. Louetta Road Bridge Texas MAIN BACK FORWARD

Sunshine Skyway Bridge
TOTALLY PRECAST BRIDGES -- CASE STUDIES Another famous bridge is the Sunshine Skyway Bridge over Tampa Bay in Florida. The piles, piers and pier caps were constructed of precast concrete elements connected together with post- tensioning threadbars. Sunshine Skyway Bridge Florida MAIN

The Future CLICK AND LEARN … MAIN FORWARD
BRIDGES -section 5 -- revised

MAIN BACK FORWARD THE FUTURE
Material properties, such as corrosion resistance, fire resistance and durability are being continuously improved and exploited. These inherent qualities of precast prestressed concrete and its considerable design flexibility also make it ideal for a wide variety of other applications: poles, piles, culverts, storage tanks, retaining walls, sound barriers and even railroad ties. MAIN BACK FORWARD

The benefits of High Performance Concrete are already beginning to be applied. These include reduced initial construction costs that result from wider girder spacing and longer spans as well as reduced long-term costs due to fewer replacements and fewer repairs. High Performance Concrete is being increasingly specified for the nation’s bridges and structures. MAIN BACK FORWARD

One form of HPC is high strength concrete. A strength of 14,000 psi was specified here for the beams of the Louetta Road Bridge, a demonstration project, located in Houston, Texas. High strength concrete was also used in this bridge for the stay-in-place deck panels, the cast-in- place concrete deck and precast segmental piers. MAIN BACK FORWARD

The Giles Road Bridge in Sarpy County, Nebraska also was constructed using High Strength Concrete. Completed in 1996, it is another example of a bridge with 12,000 to 14,000 psi concrete girders and a 5,000 to 8,000 psi concrete deck. The Federal Highway Administration, together with PCI and several states, continues to promote the use of High Performance Concrete in bridge applications. For the precast industry, High Performance Concrete often involves higher than average compressive strength. MAIN BACK FORWARD

However, other factors, such as low permeability and resistance to freeze-thaw – not just strength – may be features of High Performance Concrete depending on the geographic location of the bridge and the component for which it is used. Lightweight aggregate concrete with strengths in the 7,000 to 10,000 psi range is also being used on some newer bridges. Lightweight concrete provides reduced deadloads and seismic forces. MAIN BACK FORWARD

Strands of larger diameters and higher strengths are becoming more common as higher strength concretes are used and the demand for higher tensile force increases. When 0.6 inch diameter strands are used in conjunction with high strength concrete, in the 10,000 to 12,000 psi range, standard I-beams and other products are able to reach significantly longer spans never thought possible before. Even larger and stronger strand are on the horizon. Corrosion-resistant steels and coatings promise unlimited durability. Corrosion-resistant coatings Stainless-clad Corrosion-resistant steel 0.7"? MAIN BACK FORWARD

Nonmetallic reinforcement such as glass, carbon and aramid fiber composites will be increasingly used for special applications. A recent demonstration project has shown the compatibility of carbon fiber strands for prestressing a bridge girder. Both, internally bonded prestressing and external unbonded prestressing systems are used. MAIN BACK FORWARD

Synthetic, organic and steel fibers have been shown to improve toughness and shrinkage cracking. Recent developments in high performance fiber-reinforced concrete hold promise in terms of performance and cost- effectiveness. MAIN BACK FORWARD

Another development has been the use of precast deck panels. Used as stay-in-place forms, the panels reduce labor for field placement of reinforcing steel and concrete for bridge decks, resulting in considerable savings. The panels become composite with the field- placed concrete for live loads. They’re made of high-quality, plant- produced concrete and contain the primary tensile reinforcement between beams. They remain crack-free, protecting this important reinforcing steel. MAIN BACK FORWARD

Full-depth precast deck panels promise to provide the solution for extended closings due to deck replacement. The technique applies to new construction as well. Precast highway paving panels are being demonstrated in Texas to speed lane widenings and reduce traffic closures and detours. Refined materials and methods are making these solution an exciting new part of the designers tool box. MAIN BACK FORWARD

Another innovation is the development of horizontally curved precast concrete bridges which is creating exciting new options in contemporary bridge designs. This technique involves post- tensioning precast elements together in the plants before shipment or in the field after erection. MAIN BACK FORWARD

And yet another solution for curved structures is segmental construction. Working together with the American Segmental Bridge Institute (ASBI) and the AASHTO Bridge Subcommittee, PCI has endorsed a family of standard shapes for segmental bridges that is intended to reduce the cost of segmental bridges for smaller structures such as urban grade separations. MAIN BACK FORWARD

THE FUTURE Prestressed concrete got its start as the original composite material and further developments by the industry and its suppliers have continued to refine the performance of the product for the bridge market. MAIN BACK FORWARD

Today, it still gives the public extremely good value for its money. The reputation of the precast prestressed concrete industry has been built on the strength, imagination, consistency and integrity of its people and products alike. In the future, it will continue to be the solution of choice. MAIN BACK FORWARD

Questions? This concludes the American Institute of Architects Continuing Education Systems Program. Thank you for your time! BRIDGES -section 5 -- revised

Precast/Prestressed Bridges LIVE14BRID100

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Precast/Prestressed Bridges LIVE14BRID100

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