Paper #1122 Conference Session #B4

ULTRA-HIGH-PERFORMANCE CONCRETE: A STEP TO THE FUTURE

Angela Litvin (aml112@pitt.edu) and Mark Mancini (mam353@pitt.edu)

Abstract - Advancements in the technology of structural hand. Approximately 28.3% of bridges in United States are
design have led to a need for building materials which can functionally obsolete. Washington D.C. leads the nation with
increase the sustainability of the current infrastructure by 64.8% of its bridges being structurally deficient [11]. If these
withstanding extreme stresses and having few limitations. problems are ignored, commerce, travel, and public safety
Although products must remain cost effective, they must also will fall short of their fullest potential. The first step to an
heighten their performance and quality. The new age of advanced civilization is an adequately efficient
concrete, ultra-high-performance concrete (UHPC), infrastructure. To construct and repair this dilapidated
provides an innovative alternative to conventional concrete infrastructure, engineers must turn to new materials and
mixes. UHPC has greatly surpassed standard concrete’s designs. Since UHPC is more prevalent in Europe, it is
tensile and flexural strength through its unique proportions. under consideration as a viable option to assist in repairing
Steel reinforcements can be reduced in future structures our current infrastructure and to possibly be used to create
because of UHPC’s durable make-up. more durable structures.
Leaders of industry within the United States have
recognized UHPC’s building power and are integrating it COMPOSITION DETAILS
into design plans. Through the use of UHPC, renovated Concrete mixes differ on many levels. The composition of a
bridges and roadways will better withstand the stress of mix can dictate the capacity of its strengths. As with all
everyday use opposed to conventional concrete options. concrete, there is no definite make-up of UHPC. By
If UHPC proves to withstand the test of time, engineers comparing multiple mixes, one finds that UHPC most
can integrate it into design projects and focus on developing commonly consists of: ground quartz, silica fume, mineral
a newer and brighter infrastructure. fillers, fine silica sand, superplasticizer, water, and steel
fibers [1,10]. Larfarge and Bouygues have patented this
Key Words – Footbridge of Peace, High-Performance mixture in specific proportions under the name Ductal. A
Concrete, Mars Hill Bridge, Pi-Girders, Precast Concrete, generic form of Ductal’s mix is known as reactive powder
Steel Fibers, Ultra-High-Performance Concrete. concrete [24]. UHPC has been found to have a .15 water-
cement ratio [1]. The water to cement ratio is calculated by
OVERVIEW dividing the water in one cubic yard of the mix (in pounds)
Concrete has been an essential structural material throughout by the cement in the mix (in pounds) [26]. Silica fume,
time. Advancements in concrete have allowed engineers to which consists of amorphous silicon dioxide, is formed from
create revolutionary designs that best utilize innovative the smoke by-product of the production of silicon metal
concrete options. A viable option which is being researched [12]. “Because of its fine particles, large surface area, and
at the present time is Ultra-High-Performance Concrete the high SiO2 [silica oxide] content, silica fume is a very
(UHPC). UHPC provides an alternative form of concrete reactive pozzolan when used in concrete” [12]. About 2%,
which, under the right conditions, may optimize building by volume of fiberglass fibers can be added to improve
and increase the sustainability of the current infrastructure. ductility [1].
In contrast to UHPC, high-performance concrete (HPC)
History and Infrastructure has a similar, but slightly different composition. According
to the Federal Highway Administration (FHWA), “Any
Developed in the early 1990’s by French companies concrete which satisfies certain criteria proposed to
Bouygues, Larfarge, and Rhodia, UHPC has thus far been overcome limitations of conventional concretes may be
applied more heavily in Europe than in the United States called High-Performance concrete” [8]. HPC contains coarse
[1,2]. However, in recent years, much interest and research aggregate in addition to the fine aggregate [7]. Due to this
by United States companies has arisen due to the country’s difference, it is clear that HPC cannot be packed as densely
depleting infrastructure. With more than a 2 % increase of as UHPC due to these larger aggregates. UHPC and HPC
highway travel each year, our transportation infrastructure differ also in that HPC does not contain steel fibers in its
must continually evolve and expand to meet safety mix [7]. Without steel fibers in its makeup, HPC requires
regulations [10]. It is the job of the engineers of today to steel reinforcements to ensure reliability. In addition, HPC
design reliable structures that ensure the safety of the public. has a water to cement ratio of .29 to .4, much higher than
Through a more sustainable infrastructure, workers will need that of UHPC [8]. It can be concluded from its higher water-
to perform less routine maintenance on the structures at cement ratio that HPC requires longer time to set and cure.

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In the most standard form, conventional concrete is box on the left displays a compound with extreme particle
comprised of simply Portland cement, water, coarse hindrance. Because the fine particles cannot penetrate the
aggregate in the form of shale, and fine aggregate in the larger particles, the concrete is less dense and therefore
form of sand [9]. Although this mixture is sufficient for lacking strength. The box on the right is an example of
many building projects, it may not fulfill building optimization of particle placement. The even distribution of
requirements for larger structures without being reinforced. fine particles between the larger aggregate creates the
This need for reinforcement is due to the fact that standard stronger possible bond within the concrete.
compositions do not contain the strength enhancing
materials of HPC and UHPC. As an example, when used in
bridge construction, conventional concrete requires
significant steel reinforcement in order to meet building
standards. It can be concluded from the previously stated
composition details that UHPC, HPC, and standard concrete
mixes are all quite similar, but their subtle but influential
difference make each unique.

STRENGTH ANALYSIS
FIGURE 1
The main goal of concrete development is to maximize COMPARING STANDARD CONCRETE TO UHPC
strength, minimize the amount of concrete needed in [6]
structures, and reduce the use of steel reinforcements.
Concerning UHPC, Hesson Park states, “Because of the Many forms of simulation programs exist in order to
material’s ability to dissipate energy through superior predict the density of certain structures. According to
bonding between the matrix and the fiber, UHPC structures Professors of Civil Engineering at the Universidad
are capable of deforming and supporting flexural and tensile Autónoma de Nuevo León in México, “Comprehensive
loads even after initial cracking” [10]. As defined by RTP modeling of concrete workability and rheological behavior is
Co., flexural strength can be defined as, “the strength of a not possible without knowledge of the arrangement of
material in bending, expressed as the tensile stress of the particles, packing degree, and characteristics of porosity.
outermost fibers of a bent test sample at the instant of the The same is also true for a normal concrete” [6]. Therefore,
failure” [4]. Flexural strengths of UHPC can reach 6000 because every design differs by such a large degree, real
pounds per square inch (psi) [2]. Also, tensile strength is world applications must be tested extensively with every
“the maximum stress that a material can withstand without possible scenario before executing them on the job site.
breaking when subject to a stretching load” [4]. The tensile
strength is approximately 1305 psi after the steam-based Permeability
curing treatment and approximately 900 psi without any
treatment [20]. These higher flexural and tensile strengths UHPC is shown to be less brittle than standard concrete
are a result of the lower water-cement ratio and the addition compositions [10]. This proves to be an important advantage
of steel fibers in the UHPC mix [17]. If less water is present concerning the sustainability of UHPC structures. In most
in the mix, the chemical reaction between the water and the bridge designs, the first component requiring maintenance is
cement results in a more concentrated paste and better the bridge deck [5]. If the brittleness of the deck were
bonding [17]. reduced, the deck would in turn have a longer life span. Lutfi
Compressive stress can be defined as “the crushing load at Ay, Ph.D., Engineer of Research and Development of
the failure of a specimen divided by the original sectional Bridge Design of Skanska/Royal Institute of Technology,
area of the specimen” [4]. UHPC can achieve 18,000 to Stockholm, Sweden said, “Available research results…show
30,000 psi compressive strengths with certain curing that UHPC displays greater frost/de-icing salt resistance,
processes [1]. This benefits engineers in that bridges can be lower rate of carbonization progress and greater chloride
designed to use smaller amounts of UHPC while resistance compared with normal- and high-strength
maintaining the same strength as the design had with larger concrete” [15]. In comparison to typical concrete, UHPC’s
amounts of standard concrete or HPC. resistance to salts and chlorides can reach factors of 100 [2].
Tests showing that UHPC is nearly unaffected by chloride
Gradation ion diffusion and carbon penetration makes this material
good for bridge design [5]. Hence, it can be concluded that
Optimization of gradation is another important feature of UHPC would yield a lower life-cycle cost than other
concrete strength. The types of aggregate used in a mixture standard concrete mixes [19]. Continuing with sustainability,
dictate how tightly a mass can be compacted [6]. For by increasing the life-cycle of a structure, the time until the
example, in Figure 1, particle hindrance is displayed. The structure is no longer safe for public use will increase;
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Paper #1122 Conference Session #B4

therefore, fewer structures will need to be designed and built will be greatly deformed [22]. Concerning the differentiation
over time. on linear and circular, linear prestressing deals with beams
Bridges in areas that receive yearly snowfall must and slabs where as circular prestressing deals with items
maintain an acceptable lifespan despite frequent salt and de- with a cylindrical shape. The tendons for linear are clearly
icing materials. In this hypothetical situation, UHPC would straight lines and the tendons for circular are in the form of
prove to be beneficial. However, in areas which receive little rings [22]. Concerning both pre-tensioning and post-
to no snowfall, hence no salt or de-icing, UHPC may not tensioning, a tendon is run through the center of each mass
prove advantageous. If the structure is in an area which is of concrete. For pre-tensioning, the tendon is first stretched
subject to cold temperatures, freeze-thaw resistance must to its maximum length. The concrete is then poured over the
also be taken into consideration [17]. The repetitive action of extended cable. After the concrete has set and cured, the
the water freezing creates pressure in the pores of the tendon is released and contracts, which in turn compresses
concrete. This creates cracking and leads to a structure the surrounding concrete [22]. In contrast, post-tensioning
which will deteriorate more quickly [17]. Freeze-thaw can requires the concrete to be poured with a hollow duct
be worsened by salt and other de-icers. Because water is through the center of the concrete mass. After setting and
polar, salt ions tend to move toward these molecules; this curing, a tendon is fed through the duct and attached to an
creates the pressure within the mass that in turn leads to abutment. The other end of the cable is pulled in the reverse
further cracking [17]. direction which in turn causes the abutment to stress the
From viewing Table I, it is displayed that the water concrete mass [22]. The process to post-tension UHPC has
porosity, the oxygen permeability, and the chloride-ion been specially altered yielding “structural element
diffusion steadily decreases from standard concrete to UHPC geometry” to achieve the maximum strength [24]. Since it
[25]. Because of these statistics, it can be concluded that has been proven that prestressing increases concrete’s
since UHPC seems to be less permeable, its lifecycle will be overall strength, one can deduce that effects of prestressing
longer than the lifecycle of a standard concrete structure. on UHPC will be beneficial.
This coincides with the 1997 Uniform Building Code which
states that, a .5 water to cement ratio is necessary for Curing Processes
concrete that will be exposed to freeze-thaw and de-icing
[26]. Recall that UHPC’s water to cement ratio is .15 [1]. To achieve its maximum potential, UHPC is not able to be
This short-term investment may prove to be advantageous cured like conventional concrete. Curing is done to assist
concerning cost in that lower maintenance would be retention of water in the concrete mass. This is vital to the
required. This topic will be discussed further in the cost strength of the overall structure. Because of UHPC’s
analysis section. sensitive composition, it must be precast in order to be
prepared properly. Different curing processes result in
TABLE I different strengths of concrete. While choosing a curing
COMPARING STANDARD CONCRETE, HPC, AND UHPC process, the engineer must evaluate the strength needed in
the design to eliminate excess costs [15]. The curing
Standard HPC UHPC processes for standard concrete include standard curing,
Water water curing, and sealed curing [15]. Because UHPC sets
14-20 10-13 1.5-5
Porosity (%) quicker than standard concrete and HPC, the mix must be
Oxygen prepared and placed in the form all at once to prevent
permeability 10^-16 10^-17 <10^-19 premature setting [2]. When the top layer of UHPC beings to
(m2) cure before the rest of the mass, it can create tensile stress
Chloride-ion gradients near the surface [15]. If a builder would use these
diffusion 2.1E-11 2.1E-12 2.1E-14 faulty slabs, the structure would fall short of its fullest
factor (m2/s) strength potential. Eliminating these stress cracks is a
[25] fundamental problem that the engineers of today must
overcome before UHPC can be widely used within industry.
Prestressing Different experiments have been done to develop a better
way to cure UHPC, one such being water curing. However,
To increase the strength of any concrete, the technique of after extensive tests, it has been shown that UHPC’s
prestressing is widely used with precast concrete. A few of compression strength can be approximately 2712 psi lower
the main methods are: external/internal, linear/circular, and when water-cured than when cured under standard
pre/post-tensioning [22]. Concerning external/internal conditions [15]. Although water curing may be a logical
prestressing, forces applied by jacks against abutments solution to UHPC curing faults, it is clearly not the best
provide the necessary stresses to increase the concrete’s option [15]. It is evident that an improved curing process is
strength [22]. If the item being prestressed is even slightly needed for UHPC, thus advancing the possibilities of this
deformed, the process will be futile in that the end product material.
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Strength versus Weight costs, and on site machinery costs will decrease
proportionately [13].
A higher strength concrete gives less material and therefore Research has been conducted concerning using less
less weight [14]. If the overall weight of a structure is UHPC by volume to achieve load supporting columns which
decreased, the stress on a structure decreases because its are as strong as larger columns of standard concrete. C 40/50
base load has been reduced [14]. Vic Perry, Ductal/Larfarge is comparable to standard concrete and C180 is comparable
Vice President and general manager, states that since UHPC to UHPC. Peter Racky, University Professor and Head of the
is stronger and about 5% more dense than standard concrete, Department of Construction Management at The University
smaller and lighter pieces can be made [3]. The benefits of of Kassel in Kassel, Germany says, “Estimating the current
an overall lighter bridge include smaller cranes and fewer market price for a column of C 40/50 at approx. 2,000 € [$
trucks carrying fewer pieces to the worksite [3]. In most 2746] reveals that in the worst possible scenario, the column
structures, 65% of the load capacity is its own weight [24]. made of C 180 would have to be a maximum of 1.7 times
Because of UHPC’s strengths, more slender structures can more expensive in order to not be offset by the advantages of
be created. “The predominant condition therefore guiding the increased floor space” [13]. Engineers must always strive
structural design becomes deformation, like for steel to optimize valuable space when designing a structure. The
structures, as opposed to strength as is the case with use of smaller columns with an equal load-bearing capacity
concrete” [24]. In addition to these positive aspects, some provides the opportunity to maximize floor space [13].
problems may arise. Perry notes that, “for longer spans, the Figure 2 displays cross sections of a case study of three 3.5
elements might be too light and you’d end up with vibration meters (m) high columns. These columns are supporting a
problems” [3]. If considering UHPC for a design, an load of 40 mega newtons (MN) and each is comprised of 4%
engineer must take into account the amount of wind and reinforcement content. It is displayed that C 180 is basically
travel the structure must withstand. If the bridge receives equivalent in strength to C 40/50; however, C 180 is less
more vibrations than it can handle, structural problems may than 44% the volume of the C 40/50 column [13]. UHPC
arise. Because UHPC is a lightweight concrete solution, it is requires more energy to produce than standard concrete but
easily transported and does not influence the foundation less energy to produce than steel [13].
design [15]. This leads to less structural design problems and
lower costs for construction companies.

COST ANALYSIS
The high cost of UHPC may not be compensated by
adequate advantages in many current structures; therefore,
cost analysis is crucial before including UHPC in any design
[14]. For example, for structures which do not require such
high strengths, the use of UHPC would be disadvantageous
to the overall cost. While researching the mix, the following
concerns were brought up about the use of Ductal UHPC
mix. Because the mix is patented, it in turn has a higher cost
than standard concrete. Because of its unique composition FIGURE 2
and specific proportions, batching time increases [1]. COMPARING STANDARD CONCRETE, HPC, AND UHPC BEAMS
[13]
Chances of equipment malfunctioning is greater due to the
higher amounts of energy required to mix the concrete [1].
Racky also states that, “With use of UHPC, compared to C
The time it takes to clean the machinery also increases due
40/50, energy consumption falls by 26% and raw material
to the steel fibers and fine aggregate. Companies must
consumption by 42%” [13]. Therefore, minimization of use
ensure machinery is free of excess fibers [1]. These
of non-renewable resources can be achieved resulting in a
precautions require additional time and manpower. The
more sustainable world. Because less material is used in
reasons listed above contribute to an increase in costs such
construction, less waste material will be produced when a
as wages, energy supply, and equipment maintenance.
structure has become dilapidated. As stated previously,
However, these expenses may be offset by other factors.
companies must consider all factors when planning and
When using UHPC in a column design, additional costs
designing structures and must treat each project as its own.
may include, but are not limited to, high cost per cubic
Because no long-standing UHPC structures exist, only
meter, additional precautions concerning quality assurance,
assumptions based on research can be used when estimating
and proper licensing; however, these costs can be
life-cycle costs [13]. However, a few recently established
counterbalanced by the fact that designs include less
structures which effectively use UHPC exist within the
concrete, less reinforcing materials, and less formwork [13].
United States.
By having less materials to handle, wages, transportation
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UHPC TODAY Ricciotti, a French architect, designed this footbridge in

Seoul, South Korea to strengthen ties between France and
Mars Hill Bridge South Korea. This bridge’s archway is constructed entirely
of Ductal [23]. The most unique facet of this bridge is the
The Mars Hill Bridge in Wapello County, Iowa has been fact that its deck is merely 3 centimeters (cm) in thickness,
constructed using mainly UHPC mix. The composition of as shown in Table II [23]. It has been found that a 3 cm thick
the concrete of this bridge contains 137 pounds of Ductal slab in Ductal could be substituted for a reinforced concrete
mix, 8.03 pounds of water, 850 grams of the superplasticizer slab measuring at least 12 cm [24]. This reduction of
Glenium 3000 NS, and 9.7 pounds of steel fibers [1]. The material is a prime example of a factor that engineers must
steel fibers used were .008 inches in diameter and .50 inches consider during cost analysis. As stated previously, by using
long [2]. The only steel reinforcers used in the Mars Hill less material, overall costs may be lowered.
Bridge are U-Bars cast into the top of the beams so it can be
connected to the deck [2]. This bridge is comprised of 3, 110 TABLE II
ft., UHPC girders with no rebar for shear stirrups [3]. The SPECIFICATIONS ON THE FOOTBRIDGE OF PEACE
girders used in this bridge were designed in 45-inch precast
bulb tee design shown in Figure 3 [1]. Because of the Span 120 m (400 ft)
absence of steel in this design, sustainability increases in that Height 15 m (45 ft)
less rusting occurs. This bridge was designed under the
Bridge deck thickness 3 cm (1¼")
FHWA’s “Innovative Bridge Construction Program,” and is
a stepping-stone to future bridge design [3]. Perry says, Bridge deck width 4.3 m (17 ft)
“…Mars Hill is an important incremental step toward and Depth of cross-section 1.1 m (4 ft)
optimized solution” [3]. By incorporating UHPC into United
Total Ductal mass 220 tonnes (240 tons)
States designs, a broader variety of engineers can tackle
design flaws such as inefficiency in precasting and curing. Pre-stressed reinforcement 12 tonnes (13.2 tons)
They also can propose possible improvements which help to
best utilize UHPC’s strengths. [23]

Clinker Silo

Constructed in 2001, a clinker silo in Joppa, Illinois is the

first building in the world to have a long-span roof
completely constructed from UHPC [16]. According to the
specifications given by the 2003 Nova Award Nomination,
“The ultra light, thin, precast panels did not use any
reinforcing bars” [16]. The silo, which has a compressive
strength of 31908 psi and a flexural strength of 7250 psi,
consists of 24 half-inch, precast, pie-shaped panels [16].
This silo was built alongside two other silos which were to
use steel for the roofs [16]. It took 35 days to install each
steel roof; however it only took 11 days to install the UHPC
roof [16]. This displays UHPC’s versatility and workability
when compared to standard steel. However, concerning
workability, UHPC is lacking because efficient methods and
equipment have yet to be developed and researched [14].
Because of this, production and construction time increases
which directly increases wages and other construction costs
[14]. By using UHPC in place of steel, a project’s
completion time can be reduced, therefore cutting overall
costs.
FIGURE 3
CROSS SECTION OF THE BULB TEE DESIGN USED IN THE MARS HILL BRIDGE Shawnessy Light Rail Transit Station
[1]
The Shawnessy Light Rail Transit (LRT) Station in Calgary,
Footbridge of Peace
Alberta, Canada displays UHPC’s power and beauty. The
The Footbridge of Peace illustrates another example of station consists of twenty-four canopies supported by single
UHPC’s innovative ability to minimize weight. Rudy beams [19]. The half shell canopies, columns, ties beams,

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Paper #1122 Conference Session #B4

and struts consist of only precast UHPC [19]. The canopies

are merely 22 millimeters (mm) in width [19]. The architects
of the project wanted to create a structure that was visually
pleasing, so engineers chose UHPC because of its versatility,
durability, and low maintenance [27]. In addition to these
vital facets, the structure can be designed in an aesthetically
pleasing way. UHPC’s strengths gave engineers the ability
to make a lighter structure, giving the overall project an open
and spacious look [27]. Because little maintenance is
required for UHPC, engineers concluded that eliminating
this factor could reduce the overall costs [27]. The FIGURE 4
CROSS SECTION OF A PI-GIRDER
Shawnessy LRT station been recognized as the 2006 Charles [21]
Pankow Award for Innovation [27]. This award recognizes
the contribution of an organization that works The FHWA says, “The girder prototype is a modular
collaboratively to demonstrate innovative approaches to component designed to span 70 and 100 ft (21 and 30 m).
design, material use, or a construction process [27]. This [Figure 2] shows a UHPC pi-girder cross section prototype,
structure provides evidence that innovative material can be which is 96 inches (2.4 m) transversely and 33 inches (0.84
used not only for its strength, but also for its architectural m) deep. It can also be prestressed by up to 15 strands in
dynamics. each bulb” [21]. This advancement in technology is
necessary to achieve UHPC’s maximum potential. It has
RESEARCH been found through extensive research that prestressed pi-
To reap the full benefits of UHPC, it must not be treated as girders are a viable option for bridge construction; these pi-
conventional concrete [14]. New forms of structures must be girders surpass requirements concerning flexural design
developed to prove UHPC’s worth, just as engineers [21]. However, FHWA notes, “The load distribution
developed long suspension bridges from the ideas of high capability of the girder is limited, so distribution of live
strength wire [14]. As UHPC is not yet widely used and loads beyond adjacent girder legs is not recommended” [21].
trusted among engineers, many model-based structural Engineers must plan and design new technologies such as pi-
simulations are being conducted to study the optimization of girders in order for UHPC to become an integral part of
new structural designs which make use of UHPC [10]. The today’s infrastructure.
design parameters of these simulations include prestressing,
overall geometry, material behavior, loads, and cracking
RESULTS OF FINDINGS
criterion [10]. Through these simulations, experts have UHPC includes more strength enhancing materials than both
found that UHPC has many clear advantages such as HPC and standard concrete mixes. The addition of steel
reduction in height and weight of girders and eliminations if fibers to UHPC mixes eliminates the use of primary steel
shear reinforcement [10]. Prestressed UHPC is being reinforcements to designs. These steel fibers are meant to
considered for the design of suspension bridges decks [14]. improve current concrete options and to mimic the
Other applications include reducing the weight of the characteristics of steel. It has been found that smaller
superstructure of future cable-stayed bridges by designing a volumes of UHPC can withstand the same amount of
UHPC foundation [14]. Although it may take years for pressure as larger volumes of HPC and standard concrete.
building codes to be approved and trusted for such designs, This is key to designers as valuable space can be optimized.
through the use of UHPC in smaller structures such as the Also, UHPC is more resistant to salt and de-icing than other
ones listed above, engineers will therefore be able to collect concrete mixes. Along with most other concrete mixes,
real-world data to incorporate into design simulations, prestressing improves the strength by compressing the mass.
therefore increasing the accuracy. UHPC’s strengths are highly dependent on the type of
curing. For instance, if UHPC is cured incorrectly, it will
Beams result in strength flaws and poor composition. This
sensitivity in pouring makes UHPC impossible to pour on a
Most current structures which make use of UHPC do so in job site. Hence, for UHPC to obtain its full potential and be
the form of precast beams or girders [14]. To utilize UHPC an efficient solution, it must be precast under specialized
to its fullest potential, pi-girders, shown in Figure 4, have conditions. For this reason, UHPC is solely precast in a
been developed specifically for this new material [21]. professional plant under extreme supervision and particular
conditions. Because less volume of concrete is used in a
structure containing UHPC, the overall weight is reduced.
However, if used under incorrect circumstances, such as

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Paper #1122 Conference Session #B4

long-span bridges, vibrations may cause faults in strength [10] Park, Hesson. June 2003. “Model-Based Optimization of Ultra High
Performance Concrete Highway Bridge Girders.” Massachusettes Institute
and durability.
of Technology.
When conducting the cost analysis of a project, one must
take into account that many facets of UHPC may or may not [11] “Percent of Functionally Obsolete or Structurally Deficient (most
counterbalance each other. Engineers must take into account recent) by state.” http://www.statemaster.com/graph/trn_bri_per_fun_obs_
or_str_def-percent-functionally-obsolete-structurally-deficient. Accessed 28
that every project is unique and UHPC is only cost effective
February 2010.
in certain situations.
The Mars Hill Bridge and the clinker silo display the use [12] “What is Silica Fume?” www.silicafume.org. Accessed 28 February
of UHPC in the United States today. These examples show 2010.
that engineers are beginning to implement UHPC into the
[13] Racky, Peter. “Cost-effectiveness and Sustainability of UHPC.” 13-15
country’s infrastructure. Because only a few examples of September 2004. Proceedings of the International Symposium on Ultra
UHPC in use exist, many simulations are being conducted to High Performance Concrete. Kassel, Germany: University of Kassel, pp.
examine its possible uses. New designs must be envisioned 797-805.
in order to fully utilize UHPC’s abilities.
[14] Tang, Man-Chung. “High Performance Concrete- Past, Present and
In conclusion, UHPC seems to provide an improved and Future.” 13-15 September 2004. Proceedings of the International
more sustainable alternative to HPC and standard concrete if Symposium on Ultra High Performance Concrete. Kassel, Germany:
applied in the right setting. Due to lack of long-term University of Kassel, pp. 3-9.
structures, engineers and contractors have a right to not fully
[15] Ay, Lutfi. “Curing Tests on Ultra High Strength Plain and Steel
trust the hype of UHPC. Finally, more research and tests Fibrous Cement Based Composites.” 13-15 September 2004. Proceedings
must be done to fully evaluate UHPC. of the International Symposium on Ultra High Performance Concrete.
Kassel, Germany: University of Kassel, pp. 695-701.
REFERENCES
[16] “The World’s First Long-Span Roof Constructed in Ductal.” 2003
[1] Bierwagen, D., and Abu-Hawash, A., “Ultra High Performance Nova Award Nomination. http://www.cif.org/Nom2003/Nom22_03.pdf.
Concrete Highway Bridge.” Proceedings of the 2005 Mid-Continent Accessed 28 February 2010.
Transportation Research Symposium. August 2005. Ames, Iowa, pp.1-14.
[17] Portland Cement Association. www.cement.org. Accessed 1 March
[2] Brown, Jeff L. July 2006. “Highway Span Features Ultra-High- 2010.
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Paper #1122 Conference Session #B4

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ACKNOWLEDGMENTS
We would like to acknowledge all our professors here at The
University of Pittsburgh for assisting us to reach our goals of
one day being engineers. We also would like to thank our
Chairs, Andrew Deao, P.E., Nat Hayes, P.E., and our Co-
chair Adam Junstrom. Finally, we would like to thank our
parents, without whom we would not be here today.

University of Pittsburgh April 10, 2010

TENTH ANNUAL FRESHMAN CONFERENCE
8