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Advantages of Advantages of PrestressedPrestressedConcrete BridgesConcrete Bridges
FORWARD
Owners and designers Owners and designers
have long recognized have long recognized
the low initial cost, low the low initial cost, low
maintenance needs and maintenance needs and
long life expectancy of long life expectancy of
prestressed concrete prestressed concrete
bridges. This is bridges. This is
reflected in the reflected in the
increasing market share increasing market share
of prestressed concrete, of prestressed concrete,
which has grown from which has grown from
zero in 1950 to more zero in 1950 to more
than 55 percent today.than 55 percent today.
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
Bridges BuiltBridges Built
Source: National Bridge Inventory Data
0
10
20
30
40
50
60
50 55 60 65 70 75 80 85 90 95 00
Year Built
% Built
S/S
R/C
P/C
T
FORWARDBACK
This growth This growth
continues very continues very
rapidly, not only for rapidly, not only for
bridges in the short bridges in the short
span range, but also span range, but also
for spans in excess for spans in excess
of 150 feet which, of 150 feet which,
heretofore, has been heretofore, has been
nearly the exclusive nearly the exclusive
domain of structural domain of structural
steel.steel.
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
The following The following
examples illustrate examples illustrate
some of these key some of these key
advantages of advantages of
precast, prestressed precast, prestressed
concrete bridges: concrete bridges:
Cost EfficienciesCost Efficiencies
Structural/EngineeringStructural/Engineering
Design AestheticsDesign Aesthetics
PCI Certified QualityPCI Certified Quality
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Many bridge Many bridge
designers are designers are
surprised to learn surprised to learn
that precast, that precast,
prestressed concrete prestressed concrete
bridges are usually bridges are usually
lower in first cost lower in first cost
than all other types than all other types
of bridges. of bridges.
Coupled with savings Coupled with savings
in maintenance, in maintenance,
precast bridges offer precast bridges offer
maximum economy.maximum economy.
Cost EfficienciesCost Efficiencies
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Structural/EngineeringStructural/Engineering
Design AestheticsDesign Aesthetics
PCI Certified QualityPCI Certified Quality
Fast and Easy ConstructionFast and Easy Construction
An old bridge located on An old bridge located on a main logging road in a main logging road in Idaho was replaced with Idaho was replaced with a prestressed concrete a prestressed concrete bridge. The bridge bridge. The bridge consists of integral deck consists of integral deck beams on precast beams on precast concrete abutments and concrete abutments and wing walls. The heavy wing walls. The heavy spring runoff dictated spring runoff dictated the need for a shallow the need for a shallow superstructure, and the superstructure, and the load capacity of the load capacity of the bridge had to be bridge had to be sufficient to carry off-sufficient to carry off-highway logging trucks highway logging trucks that weigh as much as that weigh as much as 110 tons each.110 tons each.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
The precast prestressed The precast prestressed
bridge system offered bridge system offered
two principal two principal
advantages: advantages:
it was it was economicaleconomical and it and it
provided provided minimum minimum
downtimedowntime for for
construction. Project construction. Project
duration was duration was
three weeks.three weeks.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
The state of Minnesota The state of Minnesota
saved more than 16% - saved more than 16% -
a half a million dollars – a half a million dollars –
by planning for a by planning for a
prestressed alternate to prestressed alternate to
a steel bridge. a steel bridge.
The 700-foot-long The 700-foot-long
bridge is jointless up to bridge is jointless up to
the abutments and is the abutments and is
the longest continuous the longest continuous
bridge in the state. It bridge in the state. It
also contains the also contains the
longest single concrete longest single concrete
span.span.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
A Minnesota A Minnesota
transportation official transportation official
stated, “Originally, we stated, “Originally, we
didn’t think concrete didn’t think concrete
was suited to this… was suited to this…
bridge. However, the bridge. However, the
fabricator showed us fabricator showed us
it was a viable it was a viable
alternative. alternative.
Everything went Everything went
smoothly… we’re well smoothly… we’re well
satisfied…” satisfied…”
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Precast, prestressed Precast, prestressed
concrete bridge concrete bridge
components are components are easy easy
to erectto erect, particularly , particularly
when the tops of the when the tops of the
units comprise the units comprise the
entireentire
deck slab to form an deck slab to form an
“integral deck” or “integral deck” or
“full-deck” beam. “full-deck” beam.
Easy to ErectEasy to Erect
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
In a full-deck bridge, the In a full-deck bridge, the
formwork of the super formwork of the super
structure is eliminated. structure is eliminated.
Connections between Connections between
adjacent units often adjacent units often
consist of welding consist of welding
matching plates and matching plates and
grouting continuous grouting continuous
keyways. Carefully keyways. Carefully
planned details speed planned details speed
the construction process the construction process
and result in overall and result in overall
economy. economy.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Substandard bridges Substandard bridges
are easily replaced are easily replaced
with precast with precast
prestressed sections. prestressed sections.
In some cases, In some cases,
existing abutments existing abutments
can be used… can be used…
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
……but it may be easier but it may be easier and more economical and more economical to build new ones, or to build new ones, or to utilize precast to utilize precast abutments and wing abutments and wing walls supported on walls supported on cast-in-place footings. cast-in-place footings. Because precast Because precast concrete integral deck concrete integral deck bridges with precast bridges with precast abutments can be abutments can be erected without delay erected without delay in cold weather, they in cold weather, they can be opened to can be opened to traffic sooner. traffic sooner.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Bridge departments Bridge departments
are challenged to are challenged to
maintain traffic flow, maintain traffic flow,
minimize traffic minimize traffic
interruptions, and interruptions, and
reduce or eliminate reduce or eliminate
detours during detours during
construction projects.construction projects.
This Florida bridge, This Florida bridge,
damaged in a tanker damaged in a tanker
fire, was completely fire, was completely
rebuilt and opened to rebuilt and opened to
traffic in 18 days.traffic in 18 days.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Fast ConstructionFast Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
The The fast constructionfast construction
of precast concrete of precast concrete
integral deck bridges is a integral deck bridges is a
key advantage. Precast key advantage. Precast
concrete bridges can be concrete bridges can be
installed during all installed during all
seasonsseasons and opened to and opened to
traffic more rapidly than traffic more rapidly than
any other permanent any other permanent
type of bridge, because type of bridge, because
of the availability of of the availability of
plant-produced sections plant-produced sections
and the speed of and the speed of
erecting and finishing erecting and finishing
construction. construction.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Fast ConstructionFast ConstructionAll SeasonsAll Seasons
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Replacing this bridge onReplacing this bridge on
US Route 95 in Idaho US Route 95 in Idaho
illustrates another illustrates another
example of the example of the
advantages of very fast advantages of very fast
construction:construction:
New Year’s Day: Rains New Year’s Day: Rains
and melting snow and melting snow
washed out this bridge washed out this bridge
over the Little Salmon over the Little Salmon
River linking the River linking the
northern and southern northern and southern
parts of the state.parts of the state.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
FastFastConstructionConstruction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
January 4: The Idaho January 4: The Idaho Department of Department of Transportation contacted Transportation contacted the precaster to investigate the precaster to investigate solutions. They determined solutions. They determined that the fastest way to that the fastest way to replace the three spans was replace the three spans was to use a singleto use a single80-foot span comprised of 80-foot span comprised of bulb-tees with an integral bulb-tees with an integral deck. The top flange would deck. The top flange would be 8-inches thick and be 8-inches thick and 8'-6" wide. The end 8'-6" wide. The end diaphragms would also be diaphragms would also be precast onto the girder precast onto the girder ends.ends.
January 8: Engineers in the January 8: Engineers in the Bridge Section approved Bridge Section approved shop drawings and shop drawings and tensioning calculations.tensioning calculations.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Fast ConstructionFast Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
January 18: Bulb-tees January 18: Bulb-tees were shipped 240 miles were shipped 240 miles and set in place…just 17 and set in place…just 17 days after the flood! days after the flood! Included in the shipment Included in the shipment was intermediate steel was intermediate steel diaphragms, guard rail diaphragms, guard rail posts and guard rail…all posts and guard rail…all the components to the components to complete the structure.complete the structure.
January 25: The project January 25: The project was completed. The was completed. The bridge was in service bridge was in service just 24 days after the just 24 days after the flood!flood!
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Fast ConstructionFast Construction
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
As a result of a Winter As a result of a Winter flood, this single lane flood, this single lane bridge on a major forest bridge on a major forest road was washed out, road was washed out, cutting access to a U.S. cutting access to a U.S. highway for a half dozen highway for a half dozen residents…including one residents…including one with a senior needing with a senior needing continuing medical care.continuing medical care.
Within only 15 of receiving Within only 15 of receiving plans, the precaster had plans, the precaster had fabricated the 135-foot-fabricated the 135-foot-long spans with 7’-6”-wide long spans with 7’-6”-wide integral decks, and the integral decks, and the bridge was opened to traffic bridge was opened to traffic 3 days later – 18 days in all.3 days later – 18 days in all.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Simple SolutionSimple Solution
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
In Ketchikan, Alaska a bridge In Ketchikan, Alaska a bridge on the only highway to the on the only highway to the north was washed out when north was washed out when an old dam gave way on an old dam gave way on October 26. Integral deck October 26. Integral deck girders were selected for the girders were selected for the 85-ft span. The 12 girders 85-ft span. The 12 girders were designed and precast in were designed and precast in the state of Washington, then the state of Washington, then shipped by rail and barge to shipped by rail and barge to Alaska. The girders were Alaska. The girders were installed and the bridge was installed and the bridge was completed and opened to completed and opened to traffic on December 19 - only traffic on December 19 - only 54 days after the washout - 54 days after the washout - despite the problems of despite the problems of design, remote location, design, remote location, great distances, and adverse great distances, and adverse weather conditions during weather conditions during the onset of an Alaskan the onset of an Alaskan winter!winter!
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
AdverseAdverseWeatherWeatherConditionsConditions
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
To accurately compare To accurately compare
costs, consider a costs, consider a
bridge’s life-cycle: bridge’s life-cycle:
The initial cost of the The initial cost of the
structure must be structure must be
added to the total added to the total
operating cost.operating cost.
For stationary bridges, For stationary bridges,
the operating cost is the operating cost is
the maintenance cost.the maintenance cost.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Life Cycle Cost =
Initial Structure +
Total Operating Costs(Maintenance)
Life Cycle Cost =
Initial Structure +
Total Operating Costs(Maintenance)
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
The durability of precast The durability of precast
prestressed concrete prestressed concrete
bridges designed and built bridges designed and built
in accordance with in accordance with
AASHTO or AREMA AASHTO or AREMA
specifications means there specifications means there
should be little, if any should be little, if any
need for maintenance. need for maintenance.
One of the reasons One of the reasons
designers select integral designers select integral
deck prestressed concrete deck prestressed concrete
is the durability of the is the durability of the
precast, prestressed precast, prestressed
concrete and the resulting concrete and the resulting
low maintenance low maintenance
requirements.requirements.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
DurableDurable
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Fatigue problems are Fatigue problems are
nonexistent because nonexistent because
only minor net only minor net
stresses are induced stresses are induced
by traffic loads. by traffic loads.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
DurableDurable
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
And of course, no painting And of course, no painting
is needed. Some bridge is needed. Some bridge
engineers estimate the engineers estimate the
life-cycle cost of re-life-cycle cost of re-
painting steel bridges to painting steel bridges to
be 15 to 25% of the initial be 15 to 25% of the initial
cost. Painting bridges is cost. Painting bridges is
environmentally environmentally
unfriendly and can be unfriendly and can be
especially dangerous or especially dangerous or
expensive when done expensive when done
over busy highways, over busy highways,
streams, railroad rights-streams, railroad rights-
of-way or in rugged of-way or in rugged
terrain.terrain.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Painting Steel BridgePainting Steel Bridge
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
On the Illinois Toll Highway, On the Illinois Toll Highway, the superstructures of 224 the superstructures of 224 bridges are precast bridges are precast prestressed concrete prestressed concrete beams. These bridges, beams. These bridges, built during 1957 and 1958, built during 1957 and 1958, have withstood heavy have withstood heavy traffic and severe traffic and severe weathering and yet require weathering and yet require very little maintenance. very little maintenance. Other projects in all parts of Other projects in all parts of North America have North America have exhibited similar exhibited similar experience ‑ little or no experience ‑ little or no maintenance has been maintenance has been required on precast required on precast prestressed concrete prestressed concrete bridges.bridges.
Cost Efficiencies andSpeed of ConstructionCost Efficiencies andSpeed of Construction
Minimal MaintenanceMinimal Maintenance
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
In addition to its cost In addition to its cost
efficiencies and efficiencies and
speed of speed of
construction, precast construction, precast
concrete provides concrete provides
important structural important structural
and and engineering engineering
advantagesadvantages as as
well. well.
Cost EfficienciesCost Efficiencies
Structural/EngineeringStructural/Engineering
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Design AestheticsDesign Aesthetics
PCI Certified QualityPCI Certified Quality
A common requirement A common requirement
of many bridges is that of many bridges is that
the superstructure be as the superstructure be as
shallow as possible in shallow as possible in
order to provide order to provide
maximum clearance with maximum clearance with
minimum approach minimum approach
grades.grades.
Through the technique of Through the technique of
prestressing, the prestressing, the
designer can utilize the designer can utilize the
maximum possible span-maximum possible span-
to-depth ratio. This to-depth ratio. This
superstructure occupies superstructure occupies
just 13 inches just 13 inches
of profile.of profile.
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
Shallow SuperstructureShallow Superstructure
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Span-to-depth ratios as Span-to-depth ratios as
high as 30:1 can be high as 30:1 can be
achieved with solid slabs, achieved with solid slabs,
voided slabs, box beams, voided slabs, box beams,
multi-stemmed units, or multi-stemmed units, or
bulb-tee sections. Even bulb-tee sections. Even
though deeper sections will though deeper sections will
require less prestressing require less prestressing
steel, the overall economy steel, the overall economy
of a project may dictate the of a project may dictate the
highest possible span-to-highest possible span-to-
depth ratio.depth ratio.
These HPC girders are These HPC girders are
4'-6" deep and span 157 ft. 4'-6" deep and span 157 ft.
A span/depth ratio of A span/depth ratio of
nearly 35!nearly 35!
Shallow SuperstructureShallow Superstructure
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Precast prestressed Precast prestressed concrete integral deck concrete integral deck girders were selected to girders were selected to provide a shallow provide a shallow superstructure for a superstructure for a bridge over a busy bridge over a busy urban highway in urban highway in Denver. Even though Denver. Even though the bridge must carry the bridge must carry frequent heavy truck frequent heavy truck traffic, the total depth traffic, the total depth of the girders is only 3 of the girders is only 3 feet, including the 3-feet, including the 3-inch wearing surface, inch wearing surface, for a span of 80 feet.for a span of 80 feet.
Adaptable to Many SituationsAdaptable to Many Situations
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
This bridge illustrates This bridge illustrates
the high span-to-depth the high span-to-depth
ratios possible with ratios possible with
integral deck integral deck
prestressed concrete.prestressed concrete.
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
High Span-to-Depth RatioHigh Span-to-Depth Ratio
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Bridges are subjected to Bridges are subjected to an assortment of hostile an assortment of hostile environments as well as environments as well as repeated impact loadings. repeated impact loadings. Some must endure Some must endure intense sun, extreme intense sun, extreme temperatures and temperatures and brackish waters. Others brackish waters. Others must withstand not only must withstand not only the freezing and thawing the freezing and thawing provided by nature but provided by nature but also the potential for also the potential for damage through the use damage through the use of de-icer chemicals. of de-icer chemicals. Dense, high strength Dense, high strength prestressed concrete has prestressed concrete has excellent freeze-thaw and excellent freeze-thaw and chemical resistance. chemical resistance.
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Greater Greater fire fire
resistanceresistance is another is another
advantage. This timber advantage. This timber
bridge experienced a bridge experienced a
dramatic fire… dramatic fire…
Fire ResistanceFire Resistance
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
……it was replaced by a it was replaced by a
low maintenance low maintenance
prestressed concrete prestressed concrete
bridge erected without bridge erected without
falsework over an falsework over an
environmentally-environmentally-
sensitive area…sensitive area…
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Prestressed concrete Prestressed concrete bridges have bridges have excellent excellent riding characteristicsriding characteristics that minimize traffic that minimize traffic vibrations. The public will vibrations. The public will not only not only bebe safe but also safe but also feelfeel secure and secure and comfortable on a comfortable on a prestressed concrete prestressed concrete bridge. Traffic vibrations bridge. Traffic vibrations are held to an absolute are held to an absolute minimum. The owner will minimum. The owner will have a structure on which have a structure on which the deck is less likely to the deck is less likely to crack prematurely. crack prematurely. Continuous spans even Continuous spans even hold deck joints to a hold deck joints to a smooth minimum.smooth minimum.
Excellent Riding CharacteristicsExcellent Riding Characteristics
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Steel girder bridges frequently Steel girder bridges frequently exhibit noticeable vibrations. exhibit noticeable vibrations. The natural frequency of The natural frequency of vibration of these bridges often vibration of these bridges often coincides with the frequencies coincides with the frequencies of traffic and then resonance of traffic and then resonance occurs. Because of their mass occurs. Because of their mass and stiffness, the natural and stiffness, the natural frequency of vibration of frequency of vibration of prestressed girder bridges prestressed girder bridges rarely coincides with the rarely coincides with the vehicle frequencies. vehicle frequencies. Documented cases show that Documented cases show that light bulbs in fixtures installed light bulbs in fixtures installed on steel bridges burn out more on steel bridges burn out more rapidly as a result of such rapidly as a result of such vibrations. Reports are vibrations. Reports are surfacing that indicate decks surfacing that indicate decks on steel bridges are more on steel bridges are more prone to cracking and prone to cracking and deterioration. deterioration.
Structural/EngineeringAdvantagesStructural/EngineeringAdvantages
Excellent Riding CharacteristicsExcellent Riding Characteristics
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
The clean, attractive The clean, attractive
lines of concrete lines of concrete
beams also help beams also help
bridge designers bridge designers
meet the meet the
most demanding most demanding
aesthetic aesthetic
requirements. requirements.
Cost EfficienciesCost Efficiencies
Design AestheticsDesign Aesthetics
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Structural/EngineeringStructural/Engineering
PCI Certified QualityPCI Certified Quality
Prestressed concrete Prestressed concrete
bridges can be bridges can be
attractive from above, attractive from above,
below, and from the below, and from the
side because of the side because of the
simple and clean simple and clean
shapes of the members shapes of the members
used. The high span-to-used. The high span-to-
depth ratios made depth ratios made
possible through the possible through the
use of prestressing, use of prestressing,
result in strong, tough, result in strong, tough,
durable and yet durable and yet
graceful bridges. graceful bridges.
Design AestheticsDesign Aesthetics
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Prestressed concrete Prestressed concrete
is efficient because it is efficient because it
is a composite of is a composite of
high-strength steel high-strength steel
and high-performance and high-performance
concrete. To ensure concrete. To ensure
this efficiency and to this efficiency and to
comply with exacting comply with exacting
project specifications, project specifications,
precasting plants precasting plants
have developed have developed
sophisticated quality sophisticated quality
assurance programs. assurance programs.
Cost EfficienciesCost Efficiencies
PCI Certified QualityPCI Certified Quality
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Structural/EngineeringStructural/Engineering
Design AestheticsDesign Aesthetics
Precast, prestressed Precast, prestressed
concrete products are concrete products are
inspectedinspected both during both during
and following and following
production. production.
In fact, every operation In fact, every operation
in the manufacturing in the manufacturing
process provides a process provides a
point of inspection and point of inspection and
control. control.
PCI Certified QualityPCI Certified Quality
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Today’s bridge designs Today’s bridge designs
use more high-use more high-
performance materials performance materials
and sophisticated and sophisticated
solutions than ever solutions than ever
before. More and more, before. More and more,
engineers are requiring engineers are requiring
only qualified sources only qualified sources
with certified with certified
technicians and technicians and
inspectors. inspectors.
PCI Certified QualityPCI Certified Quality
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
A plant that is PCI-certified A plant that is PCI-certified tells the engineer five tells the engineer five important things:important things:
PCI Certified QualityPCI Certified Quality
Independent Auditors;Unannounced Audits
Audits Based onNational Standards
1.1. The production facility has The production facility has demonstrated its demonstrated its capability to produce capability to produce quality products to the quality products to the satisfaction of a nationally satisfaction of a nationally recognized, independent recognized, independent consulting engineering consulting engineering and inspection firm and inspection firm engaged by PCI for engaged by PCI for multiple, unannounced multiple, unannounced annual audits.annual audits.
2.2. The rigid audits the plant The rigid audits the plant undergoes are based on undergoes are based on published industry published industry standards – the standards – the PCI PCI Manual for Quality Manual for Quality Control for Plants and Control for Plants and Production of Precast Production of Precast Structural Concrete.Structural Concrete.
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
Five important things cont.:Five important things cont.:
3.3. The plant practices a The plant practices a documented and PCI-documented and PCI-approved quality approved quality assurance program open assurance program open for review.for review.
4.4. The plant has PCI-certified The plant has PCI-certified QC personnel.QC personnel.
5.5. The producer has PCI The producer has PCI confirmed capabilitiesconfirmed capabilities. .
PCI Certified QualityPCI Certified Quality
Independent Auditors;Unannounced Audits
Audits Based onNational Standards
Documented Quality System
Certified Personnel
Confirmed Capabilities
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
FORWARDBACK
To maintain PCI Certification, To maintain PCI Certification, producers are audited and producers are audited and graded semi-annually on more graded semi-annually on more than 150 items that include than 150 items that include an inspection of all raw an inspection of all raw materials; concrete mixing, materials; concrete mixing, placing, finishing and curing; placing, finishing and curing; tensioning and de-tensioning tensioning and de-tensioning of strands; temperature of strands; temperature controls; stripping, stockpiling controls; stripping, stockpiling and inspection of product. In and inspection of product. In addition, engineering, shop addition, engineering, shop drawings, record keeping, drawings, record keeping, purchasing, personnel purchasing, personnel training, and many other training, and many other practices related to quality practices related to quality production are examined. production are examined. Failure to maintain acceptable Failure to maintain acceptable standards makes loss of standards makes loss of certification mandatory. certification mandatory.
PCI Certified QualityPCI Certified Quality
ADVANTAGES OF PRESTRESSED BRIDGES -- CASE STUDIES
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