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Bridging the Centuries:
Moving Virginia's Bridge Program Into the 21st Century
by Claude S. Napier Jr., Wallace T. McKeel Jr., and Michael M. Sprinkel
The Virginia Department of Transportation (VDOT) has the
enormous job of maintaining 90,000 kilometers of highways - the third
largest state-maintained highway system in the United States. Another
16,000 kilometers of urban streets are maintained by cities and towns
with the help of state funds. VDOT's system includes approximately 13,000
bridges meeting the requirements of the National Bridge Inspection Standards
and another 8,000 smaller structures. More than 30 percent of Virginia's
bridges are structurally deficient or functionally obsolete.
To address the deficient bridges and maintain its other
structures, VDOT must get the most for its bridge dollars. This means
making the correct decisions on whether to maintain, rehabilitate, replace,
load restrict, close, or do nothing to a bridge. Each bridge must be considered
in relation to all other system demands, and a rational method of comparison
must be used. The key to a successful bridge program is to identify the
trade-offs so that bridge projects can be developed by priority and funds
can be allocated efficiently. To best determine which projects should
receive the highest priority and what improvements are the most appropriate,
bridge engineers, researchers, and managers must provide the tools needed
to make accurate decisions.
A strong research program is part of the effort. Research
is necessary both to evaluate new technologies before they are implemented
and to help solve problems we are currently experiencing. In the future,
the challenge of meeting the demand for cost-effective bridges will depend
not only on new technologies but also on innovative ideas for the use
of current and past technologies.
VDOT is unique in that it has a research organization that
is currently celebrating 50 years of excellence in research. The Virginia
Transportation Research Council (VTRC) was established in 1948 with the
central goal "to discover, to innovate, to teach, and to learn." Its mission
today is "to bring innovation to transportation." VTRC promotes excellence
in transportation through objective research and superior technical services.
VTRC is organized with four research teams: the Pavement
and Structures Team; the Materials Team; the Socio-Economics, Environmental,
and Transportation Systems Team; and the Safety Team. The Pavement and
Structures Team and the Materials Team provide the primary support for
the bridge program. The Socio-Economics, Environmental, and Transportation
Systems Team provides support for historic preservation and hydraulics.
VTRC works closely with the operations personnel of VDOT.
More than 200 of VDOT's management and technical personnel participate
in the research effort as members of research advisory committees. For
the bridge program, there is close coordination with VDOT's Structure
and Bridge, Materials, Construction, and Maintenance divisions; the nine
field districts; and the Federal Highway Administration (FHWA) through
three key research advisory committees. They are the bridge committee,
the concrete committee, and the geotechnical committee. These committees
have members from the operational divisions, field districts, VTRC, FHWA,
industry associations, and academia to advise and direct the research
and to facilitate the implementation of the recommendations of the teams
and committees.
The research and technology programs for VDOT encompass
the rehabilitation and replacement of bridges as well as the design and
construction of new structures. VTRC's assistance ranges from the simple
to the complex and addresses the assessment of the physical conditions
of bridges and different methodologies for treatment.
Assessment and Rehabilitation
of Structures
Nondestructive Evaluations of Structures
Major emphasis is placed on evaluating and minimizing the deterioration
of all types of existing structures. Considerable progress has been made
in recent years in the development, refinement, and advancement of nondestructive
evaluation techniques.
Acoustic Emission Monitoring
A recently completed study shows that acoustic emission monitoring can
be used to remotely monitor cracks in steel bridge elements. It is the
only method that can distinguish between active and benign cracks. The
real-time monitoring of steel bridge deterioration can reduce the number
of visual inspections and provide for more efficient inspection, repair,
and replacement decisions.
Crawling Robotics System
A crawling robotics system is being developed for the remote visual and
ultrasonic inspection of steel bridge members. A third-generation robot
can rapidly climb a steel high-mast light pole and allow for the inspection
of connections that are subject to cracking. A fourth-generation robot
(Robo Snake) is expected to traverse obstacles such as stiffeners and
diaphragms and allow for inspection of steel beams and box girders. The
work has the potential to reduce the cost of the inspection of structures
and improve safety. The research was co-sponsored with FHWA's Office of
Technology Applications (OTA) funds and is being conducted in conjunction
with the University of Virginia's (UVA) School of Engineering and Applied
Science.
High-Tech Alternatives for Removing Structural Steel
Paint
There are two very different technologies for removing bridge paint (typically
lead-based systems) that Virginia is actively examining.
ElectroStrip is a proprietary method that
uses an electro-chemical reaction to cause paint to debond from its metal
substrate. The process uses high current and low direct current (DC) voltage
to cause the paint to lift from the steel. The paint is retained in a
pad material that serves as the anode. The pad material with the paint
residue is packaged and transported to an appropriate disposal or recycling
site. Compared to conventional grit blasting, the process is very clean,
quiet, more worker-friendly, and much less expensive. Containment requirements
are much less than for conventional methods of paint removal. It will
permit full removal in situations in which conventional methods would
not be practicable. A full-scale field trial was recently demonstrated
on a bridge on I-66 over a local street in Arlington County.
A less-developed technology being examined uses high-energy physics plasma
techniques to remove paint from bridge steel. Called a pulsed plasma jet,
operating repetitively, it removes paint by ablating it. That is, the
plasma - ionized gases at very high temperatures (more than 3,000 degrees
Celsius) - "cooks" the paint off of the steel but doesn't last long enough
(as little as 1/1000th of a second) to damage the steel. The plasma jet
is designed to operate in a continuous mode with multiple devices for
production purposes. The cyclic rate will vary from 10 to 1,000 hertz.
A vacuum arrangement around the device will collect the paint debris for
appropriate disposal and/or recycling.
Engineering and design is ongoing, and the company is working
toward a trial with real bridge steel early in 1999.
Rehabilitation of Reinforced
Concrete Structures
Various activities have been undertaken in the last several
years to address the expensive problem of chloride-induced corrosion of
reinforcing steel in concrete bridges. To prevent ongoing reinforcing
steel corrosion from causing structures to deteriorate prematurely, the
following rehabilitation methods are under study:
- Cathodic protection (CP).
- Electrochemical chloride extraction (ECE).
- Removal of chloride-contaminated concrete and installation
of overlays.
- Patching and overlaying decks with concrete containing corrosion-inhibiting
admixtures.
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Electrochemical Treatments of Concrete Bridges
Recent experiences by state highway agencies with rehabilitation of concrete
bridges show that once the concrete is contaminated with sufficient chloride
ions to cause steel corrosion and concrete delamination, rehabilitation
procedures consisting of repair of the damaged concrete and subsequent
application of an overlay, sealer, or membrane are not effective in stopping
corrosion unless all chloride-contaminated concrete is removed. Electrochemical
imbalances between the new and contaminated concrete often have sufficient
potential differences to sustain corrosion again in the steel bars. Consequently,
the electrochemical measures such as CP and ECE are the only rehabilitation
methods that are known to overcome this electrochemical imbalance phenomenon.
Cathodic Protection
This method controls the flow of electrons in the steel/concrete system
so that anodic current from the reinforcing steel is prevented. Cathodic
protection can be applied on a structure in two ways: (1) by use of impressed
current, and (2) by use of galvanic current. Both require the installation
of a suitable anode - either applied on the surface of the concrete or
embedded just below the surface of the concrete, depending on the anode
systems involved. In the first approach, a rectifier is used to provide
a controlled amount of direct current to flow between the anode and the
reinforcing steel, which becomes the cathode. In the second approach,
a suitable anodic metal is used to provide a flow of natural direct current
between the metal and the steel, in accordance with the potential difference
between the two materials.
Proper selection of anode systems is critical to the effectiveness
of any CP system, regardless of the approach selected, and efforts at
VTRC have been directed at identifying the best anode systems for each
possible situation or environment.
Impressed-Current CP of Bridge Decks
In addition to having long service life and the ability to effectively
distribute the direct current across a concrete deck, anodes for use in
this type of CP also have to be strong enough to withstand traffic loads
and have to be compatible with the other more conventional rehabilitation
procedures. For this purpose, slotted titanium mesh anode systems without
overlays were tested on some concrete decks. The testings confirmed observations
made elsewhere that the titanium mesh is by far the best anode for use
in impressed-current CP of bridge decks.
Impressed-Current CP of Inland Bridge Piers
Because the surfaces of concrete piers are not exposed to traffic wear,
anodes do not need to be embedded in the concrete. Consequently, VTRC
field-tested a metallized zinc coating and a conductive sprayable polymer
coating developed by the Brookhaven National Laboratory under the sponsorship
of FHWA. Although the materials were found to be promising to varying
degrees, testing raised concerns about the service life, the exposure
of the workers, or the environmental issue.
The solution turned out to be electrically conductive paints - both organic-solvent
and water-based. These paints are essentially paints mixed with sufficient
graphite particles to enhance its conductivity. Field installations, some
very sizeable and as old as 10 years, have indicated that these types
of paints can provide a service life of probably at least 15 years.
In addition, testing of a new sacrificial or galvanic anode
system, zinc-hydrogel, is underway on some inland concrete. The current
comes from the difference in potential between the steel and the zinc
anode, which is available as a foil with an adhesive backing of a conductive
gel, to create the necessary current flow.
Galvanic CP of Marine Concrete Piles
Finally, several different galvanic anode systems (metallized Al-Zn coating,
Zn-hydrogel, zinc-grout jacket, and zinc-compressed panel) are being tested
on several concrete piles in Willoughby Bay, Norfolk, Va. Galvanic CP
is ideal for use in concrete piles located in seawater because the corrosion
is concentrated around the splash zone, where the concrete is often wet
and, therefore, very conductive.
Development of New Concrete-Embeddable Reference Electrodes
Possibly just as important as the anode and the rectifier in a CP system
are concrete-embeddable reference electrodes. In contrast to portable
copper/copper-sulfate electrodes being used to measure the steel-to-concrete
potentials across the surface of a concrete structure, these electrodes
can be embedded in concrete to allow for long-term monitoring of the operation
of any CP system. Unfortunately, there are concerns that the present-day
embeddable reference electrodes (such as silver/silver-chloride, molybdenum/molybdenum-oxide,
graphite, etc.) may not have sufficient service life. Consequently, research
efforts have been initiated with UVA's Center for Electrochemical Science
and Engineering to explore the application of the concept of potential-stable
galvanic couples (PSGC) in the design of an entirely new class of electrodes
that can be embedded in concrete. In addition to providing a very stable
reference potential, this new class of electrodes can be fabricated in
any desirable sizes. The results of the first-phase of research efforts
have identified three good candidate PSGC reference electrodes.
Hydraulic Cement Concrete Overlays for Bridge Decks
and Pavements
This project, in the fourth year of a five-year study, included the construction
of high-performance concrete overlays on six three-span bridges on I-95
near Emporia, two 28-span bridges on Route 60 in Virginia Beach, and 610-meter
(m) sections of pavement overlays on I-295 near Richmond, I-81 near DeWitt,
and Route 29 near Charlottesville. Bridge overlays are 32 millimeters
(mm) in minimum thickness, and the pavement overlays are 50, 75, and 100
mm thick. The Route 29 project demonstrated whitetopping. (See article
on page xx.) The I-85 and I-295 projects demonstrated overlays on continuously
reinforced-concrete pavements. Overlay concretes consisted of 32 combinations
of ingredients, including silica fume, latex, corrosion-inhibiting admixtures,
a shrinkage-reducing admixture, steel, polypropylene and polyolefin fibers,
types II and III portland cement, slag, fly ash, and topical applications
of corrosion-inhibiting admixtures. Overlays are performing well and demonstrating
the various technologies.
Field Evaluation of Corrosion Inhibitors for Concrete
For field evaluation, 156 exposure slabs, three bridge deck overlays,
and substructure patches have been constructed with and without a variety
of combinations of corrosion-inhibiting admixtures and topically applied
inhibitors. The slabs and structures are being monitored over a five-year
period for corrosion activity as part of a $250,000 FHWA-administered
pooled-fund study. Measurements are being made on the slabs for macrocell
current, macrocell potential, resistance between top and bottom rebar
mats, half-cell potentials, and rates of corrosion. After approximately
one year of exposure, measurements on the slabs show that as the chloride
ion content in the slabs increases the macrocell current, macrocell potential,
half-cell potential, and rate of corrosion increase and the resistance
decreases. The measurements also show no significant difference between
the slabs repaired with and without corrosion-inhibiting admixtures and
topical treatments. Slabs repaired with 7-percent silica fume showed half-cell
potentials that were less negative than those repaired without silica
fume.
Historic Bridges
Virginia's research efforts include an assessment of the value of her
historic bridges as well as implementation of the latest technology. Efforts
to properly manage the state's historic bridges began in the 1970s with
its initial survey of Virginia's metal-truss bridges. In the 1980s, Virginia's
concrete and masonry arches, built prior to 1932, were surveyed. The 1990s
have seen the revisiting and updating of the prior surveys to include
all remaining examples of each bridge type and new surveys of non-arched
concrete bridges built prior to 1950 and of all moveable-span bridges.
At the conclusion of each survey, the bridges were evaluated by the Historic
Structures Task Group - an interdisciplinary group made up of representatives
of VDOT, VTRC, the Virginia Department of Historic Resources, and FHWA.
Now that an inventory of significant bridges has been established, the
task group is working to develop a plan to manage and treat these historic
structures to ensure their future survival.
New Structures
Integral Abutments
Leaking joints are the major cause of deterioration of superstructure
elements below the decks and the substructures. VDOT is using more continuous
spans and integral abutments to eliminate as many deck expansion joints
as possible to reduce future maintenance expenditures. However, current
integral designs are often conservative and based on empirical values.
The design of integral bridges is complicated by the soil-structure interaction
associated with thermal movements. To optimize the future designs, more
data on the soil pressures and on the magnitude and distribution of the
stresses induced in the structure are needed.
VTRC conducted an analysis of an integral backwall bridge
on Route 257 over I-81. The bridge was instrumented during construction
and monitored for 2.5 years. The results indicated that the bridge performed
satisfactorily during the monitoring period although some settlement problems
were encountered with the approach fill. VTRC is looking at ways to minimize
the settlement behind the backwalls. Also, additional research is planned
on the resistance of pile caps and integral abutments to lateral loading
and on the performance of integral bridges.
Heated Bridge Decks
In the fall of 1996, VTRC constructed a bridge with a heated deck on Route
60 over the Buffalo River in Amherst County to improve winter-driving
safety. The site is located in the eastern foothills of the Blue Ridge
Mountains, where road conditions during winter storms can often be treacherous.
The bridge has 241 chemical-filled steel heat pipes and approximately
three kilometers of piping embedded in the concrete deck and approach
slabs.
VTRC has been evaluating the performance of the heated
bridge. Data collected from various deck and environmental sensors and
from video acquired by an infrared camera are periodically transferred
to VTRC for analysis. In addition, a Web page has been set up to monitor
the project.
Thus far, the heating system has not performed adequately.
Problems were observed with the heat distribution across the deck surface
and with heat output generated by the system. A series of experiments
were conducted using different heating fluids, including Freon 123, Freon
134a, and ethanol. Recent tests using ammonia as a heat-transfer liquid
showed promise for an effective operation. It appears that the heat output
at the deck surface will be adequate for winter operations if ammonia
is placed in the entire heating system. VTRC remains committed to ensuring
a successful monitoring of this project.
Prevention of Reinforcement Corrosion in New Concrete
Bridges
The very harsh service environments that many bridges are exposed to may
require a combination of protection systems to prevent reinforcement corrosion.
Although high-performance concrete and adequate concrete cover over reinforcement
provide a long service life, research is continuing to determine the additional
benefits to be obtained from improving the quality of concrete, using
corrosion-inhibiting admixtures and adopting corrosion-resistant reinforcement.
Shrinkage and Creep
Cracks in concrete allow the infiltration of chlorides and water and the
early age corrosion of reinforcement. Concretes that have high shrinkage
and low creep are more prone to cracking, but shrinkage and creep are
rarely included as specification requirements. The objective of this three-year
project being done by the Virginia Polytechnic Institute and State University
(Virginia Tech) is to identify, refine, and develop equipment, test procedures,
and specifications that can be implemented, thereby reducing cracking
in concrete structures.
Rheology
A study has recently been initiated to examine the rheology of a variety
of concrete mixtures, particularly high-performance concrete mixtures.
The intent is to develop and refine test procedures that measure the fresh
properties of concrete and thereby minimize placement problems and enhance
the quality of concrete structures. Conventional slump measurements often
do not provide a good indication of the workability of high-performance
concrete mixtures.
Pulsed Ultrasonic Interferometer
The study using a pulsed ultrasonic interferometer to evaluate the consolidation
of concrete found a correlation between the degree of consolidation of
concrete and ultrasonic velocity. The system can provide an indicator
of the degree of consolidation when measurements are made on fresh and
hardened concrete and thereby provide a way to know when consolidation
equipment or concrete mixtures need to be adjusted to improve consolidation.
More research is needed to implement the technique.
Corrosion-Inhibiting Admixture
The long-term benefits for concrete offered by commercially available
corrosion-inhibiting admixtures are not certain. For example, calcium
nitrite, which is an anodic inhibitor, is ineffective when the chloride-to-nitrite
ratio exceeds approximately 1.0. In addition, this inhibitor is water-soluble
and, therefore, is leachable from the concrete and should become less
effective with time. Because the chloride ions will continue to build
up in the concrete while the admixed nitrite may slowly leach out, eventually
the nitrite will not likely inhibit corrosion. Other products have not
been evaluated long enough to assess their potential.
Consequently, VTRC has started to search the new inhibitors
that have been developed for other industries looking for inhibitors that
can be used in concrete. Using tests conducted in a simulated concrete
pore solution, two promising new inhibitors have been identified. Research
efforts are underway to investigate other new inhibitors and to evaluate
commercially available inhibitors.
Epoxy-Coated Reinforcing Steel
A five-year study done by Virginia Tech under contract with VTRC has shown
that the epoxy coating on reinforcing steel used in bridge decks and substructures
in Virginia begins to debond after as little as four years in service.
The study involved the evaluation of cores taken from 21 bridge decks
and the piles in three bridges ranging in age from two to 20 years and
the evaluation of the reinforcement in exposed specimens and pour-water
solutions with various chloride contents. It was concluded that because
the coating debonds, the investigation of alternative rebar materials
providing better corrosion protection at a more favorable cost/benefit
ratio is desirable.
A new reinforcement that promised such potential is the
stainless steel-clad bar. Efforts are underway to use this new bar on
an experimental basis in a new bridge deck and to evaluate the corrosion
resistance and mechanical properties of this material.
High-Performance Materials
High-Performance Grouts for Post-Tensioning Strands
One completed project and a recently initiated project provide insight
into the problems associated with using something other than portland
cement and water to grout post-tensioning ducts. A grout mixture containing
7-percent silica fume was used to grout the ducts in the pier caps of
a major river crossing, and a mixture containing 20-percent silica sand
and 30-percent fly ash is specified for the ducts in a segmental bridge
on Virginia's experimental Smart Highway. A high-range, water-reducing
admixture must be used to obtain the fluidity required to pump the grouts.
The high-performance grouts can provide lower permeability to chloride
ions and lower shrinkage and thereby should provide greater protection
for the strands than grouts that are made of only portland cement and
water.
High-Performance Concrete
VDOT is developing and using high-performance concrete (HPC) for safe,
cost-effective structures. Seven such structures were constructed between
1995 and 1997. Compressive strengths of 48 megapascals (MPa), 55 MPa,
and 69 MPa were used in the beams of six of the structures, and/or low-permeability
special provision was used in five. The bridge with the 69-MPa beams also
had the large diameter, 15-mm strands at 50-mm spacing. Six of the structures
are carrying traffic, and the seventh will be open to traffic upon completion
of the connecting road.
High-strength, durable air-entrained concretes have been
developed at two Virginia plants using portland cement and slag at one
plant and using portland cement and silica fume in the other. In the other,
higher strengths in beams have led to economy due to a smaller section
or reduced number of beams.
VDOT experience to date shows that air-entrained HPC with
high early strengths, a 28-day strength of 48 to 69 MPa , and low permeability
can be manufactured on a production basis with locally available materials.
VDOT's HPC program is progressing successfully, and 12 more structures
have been selected, increasing the total number of HPC bridges to 19.
High-Performance Steel
High-performance steel (HPS), developed under an agreement between FHWA,
the American Iron and Steel Institute (AISI), and the U.S. Navy, became
available in 1996. HPS has been promoted as having unique chemical and
physical properties, including improved weldability using minimum preheat
to obtain sound welds, that allow more economical fabrication practices
to be employed. Tennessee and Nebraska were the first states to use HPS-70W
grade. Building on their lessons learned, Virginia decided to construct
two HPS bridges and to conduct additional research funded by FHWA OTA
to evaluate the base metal and weld material properties and their performance.
Two structures have been designed with HPS-70W steel. One
structure has a seven-span, continuous arrangement of 62 - 5@80 - 62 m.
The second structure has a five-span, continuous arrangement of 54.5 -
3@70 - 49.5 m, and it has an identical sister bridge to be fabricated
with ASTM A709M Grade 345W steel for comparison with the HPS structure.
Documentation of the entire project from design through fabrication and
erection is planned. Evaluation of the overall bridge performance under
live load as well as long-term monitoring is essential for expanded use
of this material.
Fiber-Reinforced Polymer Composites
The Tom's Creek Bridge in Blacksburg is an experimental structure designed
with a timber deck and innovative, all-composite-material beams. The bridge,
erected in the summer of 1997, is one of the first applications of composite
materials in the United States for the primary load-carrying elements
of a bridge subjected to vehicular traffic.
Composite materials, produced from polymer resins and high-strength fibers,
have the potential to be effective construction materials because of their
corrosion resistance and high strength-to-weight ratio. However, very
little data exists on the synergistic effects of vehicular loads and actual
environmental conditions that cannot be duplicated in the laboratory.
Consequently, a team of civil engineers, chemists, and composite materials
engineers from Virginia Tech, VTRC, and the VDOT Structure and Bridge
Division have collaborated to develop a testing protocol to examine the
durability of the Tom's Creek Bridge composite beams under actual field
conditions. The goals of this project are:
- To establish the baseline behavior of this innovative structure
under known live loads for comparison with future load tests
to assess its long-term structural adequacy.
- To compare the field-test results with data from load tests
previously conducted on the structure in the Structures Laboratory
at Virginia Tech.
- To establish a response/behavior benchmark for the calibration
of a model developed by researchers at Virginia Tech. This model
will be used to predict overload behavior and possible failure
modes.
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Aluminum
In a cooperative spirit to work with industry to promote the bridge application
of aluminum, VDOT committed to construct several bridges with aluminum
deck systems. The new aluminum deck is comprised entirely of extrusions
welded together at the sides, providing continuity in the top and bottom
flanges. After welding, the webs of the extruded parts form repeating
triangles, creating trusses perpendicular to the extruded direction. The
extrusions generally run longitudinally (parallel to the girders and traffic
flow). The completed proprietary deck is connected securely to the underlying
girders so that composite action is developed between the deck and the
girders. The difference in thermal expansion coefficients between steel
and aluminum induces stresses in both materials that are accounted for
in the design. The decks could be fabricated in panels as large as can
be shipped, which for highway shipment is about 4.3 m wide by 36.6 m long.
The decks are shop-coated with an epoxy-based wearing surface with a 9.53-mm
nominal thickness.
VTRC, with support from the FHWA OTA, initiated a three-part
study to evaluate the aluminum deck system. The first phase involved structural
testing and evaluation of a 2.74-m by 3.66-m deck panel by the Structures
Laboratory at FHWA's Turner-Fairbank Highway Research Center. Several
tests were conducted in which the panel was loaded to its design limit
under various support conditions. In addition, a test to failure was conducted.
The second phase involves a series of static and dynamic load tests on
a completed structure. The third phase will focus on the long-term durability
of the deck system.
Conclusion
To meet the growing demand for better, more efficient, cost-effective,
and appealing bridges with extended service lives, Virginia is moving
boldly forward with both new technologies and improvements upon current
technologies. VDOT is not rushing forward carelessly; the department is
working with its industry partners to do laboratory and field testing
and evaluations to ensure that the technologies are functionally, economically,
and aesthetically acceptable.
VTRC has nurtured an excellent working relationship with
its operational divisions and field districts, FHWA, industry, and academia
to promote technology and research. The research advisory committees are
key to the success in identifying needs, providing direction, and implementing
technologies. Also, there has been an outstanding partnership with FHWA's
Virginia Division, the Region 3 Office, the Office of Technology Applications,
and the Turner-Fairbank Highway Research Center in supporting, implementing,
and evaluating new technologies and conducting research.
There is a commitment by upper management to promote the
use of technology and research to maintain and enhance Virginia's transportation
system. VDOT employees and managers are working together to ensure that
Virginia's transportation system represents the highest standards of safety
and quality and that VDOT is a leader in using innovation and technology
to move Virginia's bridge program into the 21st century. This commitment
and effort was recognized in March 1998 when VDOT received the Federal
Highway Administrator's Public Service Award for the initiative and leadership
demonstrated by VDOT in implementing innovative design and high-performance-material
technologies in bridge construction under Section 6005, Applied Research
and Technology Program, of the Intermodal Surface Transportation Efficiency
Act of 1991.
The citation reads, in part, "Your organization's proactive
effort in fostering and applying new bridge technologies in the Commonwealth
of Virginia is commendable. Virginia is the only State to have built bridge
projects using the heated bridge deck, the thin bonded overlays, the high-performance
materials (steel, concrete, aluminum, and fiber-reinforced polymer composites),
the nondestructive evaluation/testing, and the jointless bridge technologies.
These innovative technologies have great potential to improve and enhance
the effectiveness and efficiency of the Nation's transportation system."
Claude S. Napier Jr. is the division bridge engineer in FHWA's
Virginia Division Office in Richmond, Va. He is responsible for the FHWA
bridge program, including bridge, concrete, and geotechnical technology
and research. He has 28 years of bridge design, construction, and maintenance
experience, including 20 years with FHWA. Napier is a registered professional
engineer in Virginia. He received his bachelor's and master's degrees
in civil engineering from Virginia Polytechnic Institute and State University.
Wallace T. McKeel Jr. is the research manager for
the VTRC Pavement and Structures Team in Charlottesville, Va. He manages
VDOT's research program in the structural, pavement, geotechnical, maintenance,
and field operations areas. He has 39 years of bridge design and research
experience, including 35 years with VTRC. McKeel is a registered professional
engineer in Virginia. He received his bachelor's degree in civil engineering
from the Virginia Military Institute and his master's degree in civil
engineering from the University of Virginia. He has written numerous papers
and reports primarily on the design, evaluation, and maintenance of bridges
and on the durability of drainage structures.
Michael M. Sprinkel is the research manager for
the VTRC Materials Team in Charlottesville, Va. He specializes in materials
and construction methods for the protection, repair, rehabilitation, and
replacement of bridge decks and other concrete structures. He has 26 years
of research experience. Sprinkel is a registered professional engineer
in Virginia, and he has published more than 40 papers. He received his
bachelor's and master's degrees in civil engineering from the University
of Virginia.
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