# **CASE STUDIES & LESSONS LEARNED**

### *by Claude Napier, P.E., FHWA; Edward Parker, FHWA and* 

*Madhwesh Raghavendrachar, P.E., Caltrans*

**11.1 Introduction**

Information about the HPC bridges is located in numerous published and
unpublished technical reports, papers in technical journals, symposia
proceedings and student theses. The purpose of this chapter is to
present brief case study summaries on HPC bridges that have been built,
to demonstrate the practical applications of HPC, and to provide
available references at the end of each summary for more detailed
information if desired.

**11.2 Outline for Case Studies**

The following is the outline for the Summaries.

-   Description: Identifies if the bridge is open to traffic and
    provides a summary of the

> bridge features, including location, bridge length, span lengths,
> girder spacing, HPC elements, the type environment.

-   Benefits: Highlights why HPC was used.

-   Costs: Provides the available cost (total cost, cost per square
    foot, or cost per foot) of

the structure.

-   Admixtures specified: Includes items that were required by the HPC
    special provisions.

-   Admixtures used: Identifies the actual admixtures used by the
    contractor to meet the

requirements of the specifications.

-   HPC Requirements: Identifies such HPC parameters as permeability,
    design strength

(greater than 8 ksi), high early strength, SCC/placement, lightweight
aggregate, modulus

of elasticity, and others.

-   Lessons Learned (when available): Builds on the benefits of using
    HPC and highlights

any problems experienced and how solved.

-   References: Provides references or web links for additional
    information.

The initial case study summaries are for the 18 bridges included in the
national program initiated in 1993 by FHWA to implement the use of HPC.
The program included the construction of demonstration bridges in each
of the former FHWA regions and dissemination of the technology and
results at showcase workshops. The 18 bridges were located in 13 States.
Other States have implemented the use of HPC in various bridge elements.
Case study summaries will be completed on the best innovations, with the
objective of trying to have at least one case study summary for every
state that implements HPC.

**11.3 Lessons Learned from HPC Projects**

A number of lessons have been learned from the HPC projects. Research
and FHWA demonstration HPC projects have affirmed that HPC is
constructable and can be used cost effectively in highway bridge
construction. HPC has enhanced durability characteristics and strength
parameters not normally attainable by using conventional design mixes.

The use of HPC in bridges has shown that HPC saves initial construction
cost and long-term maintenance cost by:

-   Reducing weight and using fewer lines of beams.

-   Using shallow beams to solve vertical clearance problem.

-   Increasing span lengths.

-   Increasing short- and long-term durability.

    An increasingly large number of manufacturers and contractors are
    involved in HPC production, fabrication, and construction. They have
    learned valuable lessons for improving productivity and quality and
    achieving a consistently good product. Precast prestressed concrete
    beams using concrete strength of 10,000 psi and release strength in
    the range of 7,000 to 8,000 psi can be cast on a normal daily cycle
    with only slightly higher costs over conventional concrete. For
    example, HPC concrete typically costs around 20% more than
    conventional concrete per cubic yard, . In a number of instances,
    HPC concrete has cost the same as conventional concrete because the
    fly ash and slag being used cost the same or less than the cement
    being replaced.

    A good quality product saves cost in the long run. The steps taken
    by the owner and the manufacturer to assure success and quality in
    production are vital to cost savings and profitability. Trial mix
    designs have proved to be invaluable in developing the project
    construction specifications, and in helping the manufacturers
    minimize surprises and delay in production.

    For the first time users of HPC, a test section constructed prior to
    the start of fabrication has proved to be very beneficial. The
    lessons learned from the test section can be put into practice to
    assure quality and production.

    HPC possesses all the essential elements for structural applications
    to extend service life and reduce life-cycle cost. The successful
    application depends greatly on the designers working closely with
    the local fabricators and contractors to arrive at cost-effective
    solutions.

**11.4 Project Listing**

The following are the case study summaries developed to date:

Table 11.4-1 Case Study Summaries

+----------------+-----------------------------------------------------+
| > Alabama      | > [Highway 199 over Uphapee Creek, Macon            |
|                | > County](#alabama)                                 |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > California   | > [New San Francisco -- Oakland Bay Bridge:         |
|                | > Skyway](#California)                              |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Colorado     | > [Interstate 25 over Yale Avenue,                  |
|                | > Denver](#Colorado)                                |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Georgia      | > [State Route 920 (Jonesboro Road) over            |
|                | > I-75](#Georgia)                                   |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Louisiana    | > [LA 87 over Charenton Canal in St. Mary           |
|                | > Parish](#Louisiana)                               |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Nebraska     | > [120^th^ Street and Giles Road Bridge, Sarpy      |
|                | > County](#nebraska)                                |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > New          | > [Route 104 over Newfound River,                   |
| > Hampshire    | > Bristol](#Hampshire)                              |
|                | >                                                   |
|                | > [Route 3A over Newfound River,                    |
|                | > Bristol](#route-3a-over-newfound-river-bristol)   |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > New Mexico   | > [Old Route 66 over Rio Puerco](#new-mexico)       |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > North        | > [U.S. 401 over Neuse River, Wake County](#NC)     |
| > Carolina     |                                                     |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Ohio         | > [U.S. route 22 over Crooked River at Mile Post    |
|                | > 6.57 near Cambridge in Guernsey County](#Ohio)    |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > South Dakota | > [I-29 Northbound over Railroad in Minnehana       |
|                | > County, Structure No. 50-181-155](#SD1)           |
|                | >                                                   |
|                | > [I-29 Northbound over Railroad in Minnehana       |
|                | > County, Structure No. 50-180-155](#SD2)           |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Tennessee    | > [Hickman Road over State Route 840, Dickson       |
|                | > County](#Tennessee)                               |
|                | >                                                   |
|                | > [Porter Road over State Route 840,                |
|                | > Dickson](#Tennessee2)                             |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Texas        | > [Louetta Road Overpass, SH 249,                   |
|                | > Houston](#a-texas)                                |
|                | >                                                   |
|                | > [US Route 67 over North Concho River, US Route    |
|                | > 87, and South Orient Railroad, San                |
|                | > Angelo](#Texas)                                   |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Virginia     | > [Route 40 over Falling River, Brookneal in        |
|                | > Lynchburg District](#VirginiaRoute40)             |
|                | >                                                   |
|                | > [Virginia Avenue over Clinch River,               |
|                | > Richlands](#VirginiaClinch)                       |
+----------------+-----------------------------------------------------+
|                |                                                     |
+----------------+-----------------------------------------------------+
| > Washington   | > [Eastbound lanes of State Route 18 over State     |
|                | > Route 516 in King County](#Washington)            |
+----------------+-----------------------------------------------------+

# **11.4.1 Alabama**

#  **Highway 199 over Uphapee Creek, Macon County**

Opened to traffic in April 2000, Highway 199 over Uphapee Creek is a 798
ft long bridge. It consists of seven 114 ft spans with 54 in bulb tee
girders spaced at 10 ft. The environment is considered a normal bridge
over water. The HPC elements are the substructures, girders, and deck.
The bulb tee girders cost \$120/linear ft, the substructure cost
\$24.72/ft^2^ of deck surface area, and the superstructure cost
\$16.93/ft^2^ of deck surface area.

Design of the girders for a concrete compressive strength of 10000 psi
at 28 days allowed the use of five lines of girders. Six lines would
have been required with conventional strength concrete. Eliminating a
line of girders resulted in an estimated cost savings of \$100,000.
Furthermore, the use of HPC resulted in one less pier at an estimated
savings of \$100,000. The anticipated benefits with the use of HPC are
twofold. One is a savings on initial construction costs from the use of
one less girder line and one less pier. The second is the anticipation
of a more durable concrete structure contributing to less maintenance
costs and a longer service life.

For the girders, the owner allowed the use of Class C fly ash at less
than 35% and silica fume at less than 15% of cementitious material
weight. For the deck, Class C fly ash at less than 30% and silica fume
at less than 15% of cementitious material weight was specified. Chloride
permeability thresholds were not required. The deck was required to be
wet cured for seven days.

For the girders, the contractor used 753 lb/yd^3^ of cement and 133
lb/yd^3^ of fly ash. At 28 days, compressive strength quality control
tests on the girders averaged 9920 psi. For the decks, compressive
strength quality control tests averaged 7370 psi at 28 days using 658
lb/yd^3^ of cement and 165 lb/yd^3^ of fly ash.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-9mayjun00.pdf>

[]{#California .anchor}**11.4.2 California**

#### Oakland Bay bridge: Skyway, San Francisco

The new San Francisco-Oakland bay bridge is comprised of the Signature
span, the Skyway spans, and the approach spans. This bridge, currently
under construction, is located in a marine environment over the San
Francisco Bay on Interstate 80. The design life of this bridge is 150
years.

The Skyway is a multi-span precast segmental box-girder with a typical
span length of 540 feet. The box girder is comprised of two "main"
girders spaced approximately at 26 ft. While all the components of the
new bay bridge have stringent performance requirements, this synopsis
addresses the superstructure elements of the Skyway. HPC, combined with
the segmental construction, resulted in a significant increase in design
span lengths.

The strength used in designing the precast girders of the Skyway was
8000 psi. However, the owners required a minimum modulus of 5,200,000
psi. In addition, a shrinkage limit of 0.045 % at 180 days per ASTM C
157 (7 days water cure) and a creep limit of 0.5 mils/psi @ 20% - 40%
f\'~c~ (28 days) were also specified. The use of admixtures (flyash/
silica fume/ metakaolin) was also required.

The contractors used 25% fly ash, shrinkage reducing admixtures,
retarder (Type B) and high range water reducer (Type G)*.* Concrete
strengths in excess of 10,000 psi were achieved.

[]{#Colorado .anchor}**11.4.3 Colorado**

**I-25 over Yale Avenue, Denver**

Opened to traffic in June 1998, I-25 over Yale Avenue is a 214 ft long
bridge with a 38 ft wide roadway. The two span structure utilizes 1700
mm (67 in) wide by 750 mm (29.5 in) deep box girders spaced at 1720 mm
(67.7 in). The environment is considered a normal bridge over a road.
The HPC elements are the piers, girders, and deck.

High performance concrete was specified for the box girders to meet the
requirements for long spans with a shallow superstructure depth. To
provide additional room for a turning lane, the bridge was reduced from
an original four span design to two spans. The new bridge has one pier
with four columns as compared with the previous bridge that had three
piers and a total of 45 columns. The reduction in the number of spans
and columns subsequently improved aesthetics and sight distances. The
girders cost \$188.29 per linear ft.

The owner specified a maximum fly ash percentage of 25% for the girders
and 10% for the deck. Compressive strengths were specified as 10,000 psi
at 56 days for the girders and 5076 psi at 28 days for the deck. There
were no chloride permeability requirements specified. Dependent upon the
time of the year, membrane curing followed by five days of water curing
or membrane curing followed by five days of insulating blankets was
utilized for the deck.

For the girders, the contractor used 730 lb/yd^3^ of cement and
35lb/yd^3^ of silica fume and obtained compressive strengths ranging
from 7800 to 14000 psi at 56 days. For the decks, the contractor used
712 lb/ft^3^ of cement and no fly ash or silica fume and obtained a
compressive strength averaging 5945 psi at 56 days.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-3mayjun99.pdf>

[]{#Georgia .anchor}**11.4.4 Georgia**

#  **SR 920 (Jonesboro Road) over I-75, Henry County**

Opened to traffic in February 2003, the SR 920 over I-75 bridge is 352
ft long and 90 ft wide. The structure has a four span arrangement of 53
ft, 127 ft, 127 ft, and 45 ft. The 127 ft spans use AASHTO Type IV
girders spaced at 7.6 ft. The shorter spans used AASHTO Type II girders
also spaced at 7.6 ft. The environment is considered a normal bridge
over water. The HPC elements are the girders and deck.

> The use of HPC was essential to the project because it allowed the
> Georgia Department of Transportation to use 127 ft long AASHTO Type IV
> beams. This minimized the overall depth of the superstructure and
> avoided raising the grade of the bridge and requiring the purchase of
> additional right-of-way. HPC was also used to optimize beam spacing.
> Conventional strength concrete girders would have required the use of
> five additional girders. The lower permeability of HPC is expected to
> result in a more durable structure with a longer service life and
> minimal maintenance. The total cost of the bridge was \$58.77/ft^2^ of
> deck surface area.

For the girders and deck, the owner allowed the use of Class F fly ash
ranging from 0-15% and silica fume ranging from 5-10%. The chloride
permeability requirements were less than 3000 coulombs at 56 days for
the girders and less than 2000 coulombs at 56 days for the deck. The
deck was required to be continually moist cured for seven days utilizing
burlap-polyethylene cover and soaker hoses.

For the girders, the contractor used 810 lb/yd^3^ of cement, 75 lb/yd^3^
of silica fume, and 100.6 lb/yd^3^ of Class F fly ash. The mixture
resulted in a chloride permeability less than 500 coulombs at 56 days.
For the deck, the concrete used 617 lb/yd^3^ of cement, 26 lb/yd^3^ of
silica fume, and 104 lb/yd^3^ of Class F fly ash. However, because of
mix design changes made by the contractor in the field, a much higher
than specified chloride permeability of 3963 coulombs at 56 days was
obtained.

***Lessons Learned:*** In conjunction with the Georgia's HPC project,
research was conducted by Georgia Tech to evaluate the time-dependent
behavior of HPC in prestressed girders. Two grades of HPC were
investigated for more than a year to determine their time-dependent
mechanical properties and structural responses. A large number of
compressive strength, modulus of elasticity, creep, and shrinkage tests
were conducted. The results unveiled an inaccuracy of creep and
shrinkage predictions when modeling HPC. A better model, which more
favorably compares to tested data, is being proposed. Time-dependent
prestress loss and camber were also monitored on four 33 ft 4.4 in long
AASHTO Type II girders and six 9 in X 18 in X 14 ft beams. The results
indicate that the current AASHTO LRFD Specifications and the PCI Design
Handbook significantly overestimates the time-dependent prestress loss
and deflection of HPC precast beams. The research proposes modifications
to the current specification to account for the characteristics of HPC.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:
<http://www.cement.org/pdf_files/hpc-28julaug03.pdf>

**11.**[]{#Louisiana .anchor}**4.5 Louisiana**

**LA 87 over Charenton Canal in St. Mary Parish**

Opened to traffic in November 1999, LA 87 over Charenton Canal is a 365
ft long and 46 ft 10 in wide bridge. There are five-71 ft spans of
AASHTO Type III girders spaced at 10 ft. The environment is considered a
normal bridge over water. The HPC elements are the pile, pile caps,
girders, deck, approach slabs, and barrier rails. The Type III Girders
cost \$82/linear ft, the 30-in piles cost \$105/linear ft, and the class
AA (HPC) concrete cost \$540/yd^3^.

Design of the girders with a concrete compressive strength of 9000 psi
allowed the use of five lines of girders. Six lines would have been
required with a routine concrete compressive strength of 6000 psi. The
use of high-strength concrete in the piles increased their resistance to
compressive and tensile driving stresses and allowed the casting and
shipping of longer lengths. Because of the added durability of the HPC
members, the Louisiana DOT expects a 75 to 100-year service life for the
bridge instead of the normal 50-year service life for concrete
structures.

For the girders, the owner allowed the use fly ash ([\<]{.underline}
35%) and silica fume ([\<]{.underline} 10%). For the deck, fly ash
([\<]{.underline}30%), silica fume ([\<]{.underline}10%), and ground
granulated blast furnace slag (GGBFS) ([\<]{.underline}50%) was allowed.
The chloride permeability required for the girders and the deck was 2000
coulombs or less based on AASHTO T 277 at 56 days. The deck was required
to be cured 7 days wet under burlap.

For the girders and piles, the contractor used 691 lb/yd^3^ of cement
and 296 lb/yd^3^ of fly ash and obtained a chloride permeability of
around 1100 coulombs. For the pile caps and decks, permeability of
around 1020 coulombs was obtained using 306 lb/yd^3^ of cement and 305
lb/yd^3^ of GGBFS.

##### **Lessons Learned:** *The scope of the project included a literature search, a survey of regional fabrication plants, a study of mix designs in the laboratory and in the field, fabrication and testing of full-size concrete specimens, and analysis of the test results. The test program included flexural tests of three 24-in (610‑mm)-square concrete piles, flexural and shear tests of three 54-in (1.37-m)-deep prestressed concrete bulb-tee girders, field driving of a 130-ft (39.6-m)-long prestressed concrete pile, and fatigue testing of a 54-in (1.37-m) deep prestressed concrete bulb-tee girder. The report concluded that the provisions of the AASHTO Standard Specifications for Highway Bridges are conservatively applicable to members with concrete compressive strengths up to 10,000 psi (69 MPa).* {#lessons-learned-the-scope-of-the-project-included-a-literature-search-a-survey-of-regional-fabrication-plants-a-study-of-mix-designs-in-the-laboratory-and-in-the-field-fabrication-and-testing-of-full-size-concrete-specimens-and-analysis-of-the-test-results.-the-test-program-included-flexural-tests-of-three-24-in-610mm-square-concrete-piles-flexural-and-shear-tests-of-three-54-in-1.37-m-deep-prestressed-concrete-bulb-tee-girders-field-driving-of-a-130-ft-39.6-m-long-prestressed-concrete-pile-and-fatigue-testing-of-a-54-in-1.37-m-deep-prestressed-concrete-bulb-tee-girder.-the-report-concluded-that-the-provisions-of-the-aashto-standard-specifications-for-highway-bridges-are-conservatively-applicable-to-members-with-concrete-compressive-strengths-up-to-10000-psi-69-mpa. .unnumbered}

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-8marapr00.pdf>

# **11.5.6 Nebraska**

**120^th^ Street and Giles Road Bridge, Sarpy County**

Opened to traffic in July 1996, 120^th^ Street and Giles Road Bridge is
a 225 ft long bridge. It consists of three 75 ft spans, each with NU1000
girders spaced at 12.4 ft. The environment is considered a normal bridge
over water. The HPC elements are the girders and deck. The prestressed
concrete girders cost \$741/yd^3^ and the cast-in-place concrete deck
cost \$313/yd^3^.

Design of the girders required a 56-day concrete compressive strength of
12,000 psi. Deck strength criteria included a concrete compressive
strength of 8,000 psi and a rapid chloride permeability of less than
1800 coulombs at 56 days. This resulted in seven lines of girders
compared to eleven that would have been required with conventional
strength concrete girders. Building the HPC bridge less than a half mile
away from an identical conventional concrete bridge allowed Nebraska
Department of Roads to evaluate service life and establish incremental
costs for design and construction of the HPC bridge in relation to a
conventional bridge.

For the girders, the contractor used 750 lb/yd^3^ of cement, 200
lb/yd^3^ of Class C fly ash, and 50 lb/yd^3^ of silica fume. At 56 days,
compressive strength quality control tests on the girders averaged
13,944 psi. For the deck, the contractor used 750 lb/yd^3^ of cement and
75 lb/yd^3^ of Class C fly ash. Compressive strength quality control
tests averaged 10,433 psi at 56 days. The rapid chloride permeability
measurement for the deck was 589 coulombs.

***Lessons Learned:*** Several cracks were observed on the bottom
surface of the HPC deck. These cracks were generally perpendicular to
the axis of the girders and were well distributed over the entire
surface. The orientation, distribution and narrow widths of these cracks
indicate that they are not caused by structural overstress, rather that
they are shrinkage cracks.

The cracks may have occurred due to the following reasons:

-   Strict curing requirements were applied to the top surface of the
    deck, but the bottom

surface received no special attention. Therefore, the bottom surface of
the deck was deprived of moisture needed for curing.

-   The high temperature variation between the top surface and the
    bottom surface of the

deck.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-3mayjun99.pdf>

[]{#Hampshire .anchor}**11.4.7a New Hampshire**

**Route 104 over the Newfound River, Bristol**

Opened to traffic in 1996, Route 104 over the Newfound River is a single
span, 65 ft long, and 57 ft 6 in wide bridge. The superstructure
consists of five AASHTO Type III girders spaced at 12 ft 6 in. The
environment is considered a normal bridge over water. The HPC elements
are the girders, deck, and approach slabs.

As their first HPC bridge, New Hampshire had three objectives 1)
evaluate a structure which was representative of the majority of
structures built in the State; 2) choose a practical concrete mix which
would have an easily attainable strength and durability; and 3) test and
evaluate the performance of the HPC and the in-situ performance of the
bridge itself. The girders were designed for a concrete compressive
strength of 8000 psi at 28 days while the deck was designed for a
strength of 6000 psi*.* The cost of the project was \$59/ft^2^ of deck
surface area as compared to a conventional strength bridge which costs
\$48/ft ^2^.

For the deck and approach slabs, 50 lb/yd^3^of silica fume was
specified. At 56 days, less than 1000 coulombs of chloride permeability
was required for the girders and deck. The deck was wet cured for four
days with cotton mats and sprinklers.

For the girders, the contractor used 777 lb/yd^3^ of cement and 50
lb/yd^3^ of silica fume. At 56 days, compressive strength quality
control tests on the girders averaged 9000 psi. For the decks,
compressive strength quality control tests averaged 9600 psi at 56 days
using 660 lb/yd^3^ of cement and 53 lb/yd^3^ of silica fume. The
chloride permeability at 56 days averaged 753 coulombs for the decks.

***Lessons Learned:*** Trial batching and trial pour played an important
role in optimizing the development and placement of the HPC deck.
Modifications were made throughout the pre-pour process to improve the
mix proportions and eliminate unforeseeable problems. The final product
exceeded expectations. No visible cracks in the deck were found during
subsequent post-construction inspections. Excellent results were
obtained for the 28-day concrete strength, freeze-thaw durability,
chloride ion permeability, and scaling tests.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-4julaug99.pdf>

**11.4.7b New Hampshire**

#  **Route 3A over Newfound River, Bristol**

Opened to traffic in January 1999, Route 3A over the Newfound River is a
65 ft long and 39 ft 6 in wide bridge. The structure has a single span
and uses New England 1000 Bulb Tee girders spaced at 11 ft 6 in. The
environment is considered a normal bridge over water. The HPC elements
are the girders, precast panels, and cast-in-place deck.

> The use of HPC allowed the New Hampshire DOT to use a shallower girder
> and wider spacing than if conventional strength concrete had been
> used. In addition, one line of girders was eliminated. The
> superstructure consisted of precast prestressed concrete panels as
> formwork and a composite cast-in-place 5.5 in deck. The concrete in
> the girders and deck had to meet low permeability requirements, which
> are expected to result in a longer service life with minimal
> maintenance.

For deck, the owner allowed the use of silica fume at 7.5% of cementious
material weight. The chloride permeability specifications were less than
1000 coulombs at 56 days for the deck and less than 1500 coulombs at 56
days for the girders. The deck was required to be continually moist
cured for seven days utilizing cotton mats and soaker hoses.

For the girders, the contractor used 550 lb/yd^3^ of cement and 50
lb/yd^3^ of silica fume. For the deck, the contractor used 660 lb/yd^3^
of cement and 52 lb/yd^3^ of silica fume. The girders achieve an average
compressive strength at 28 days of 11,200 psi. The deck achieved an
average compressive strength at 28 days of 9004 psi. Both the deck and
girders obtained permeability well below the specified limit of 1000
coulombs.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-17sepoct01.pdf>

# **11.4.8 New Mexico**

**Old Route 66 over Rio Puerco, Albuquerque**

Opened to traffic in December 2000, Old Route 66 over Rio Puerco is a
293.3 ft long bridge. It consists of three spans of 96.1, 101.1 and 96.1
ft with four 63 in bulb tee girders spaced at 12.6 ft. The environment
is considered a normal bridge over water. The HPC elements are the
girders and deck. The overall cost of the bridge was \$2,896,701.

New Mexico DOT's objective was to establish the viability of HPC in
their State. As a result of the success of HPC, prestressed concrete
beams are now produced with design concrete strengths of 7000 psi as
compared to previous concrete design strengths of 6000 psi. More HPC
projects are planned. Cost comparisons show that six lines of BT63
girders utilizing HPC would provide a superstructure cost savings of
7-10 percent, compared to conventional strength concrete using eight
lines of BT63 girders. The use of BT63 girders with HPC was estimated to
provide a cost savings of 6 to 9 percent compared to the use of Type IV
girders with HPC.

For the girders, the contractor used 846 lb/yd^3^ of cement and 127
lb/yd^3^ of Class F fly ash. The precast beams had specified concrete
compressive strengths of 7000 psi at release and 10,000 psi at 56 days.
A 3-day curing period was required to achieve the concrete strengths.
Actual average strengths at release and 56 days were 7500 and 10,340
psi, respectively.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-25novdec02.pdf>

[]{#NC .anchor}**11.4.9 North Carolina**

**US 401 over Neuse River, Wake County**

Fully opened to traffic in September 2002, the US 401 over the Neuse
River bridge is 299 ft long and 42 ft wide. There are four spans, two at
92 ft and two at 57 ft. The 92 ft spans use AASHTO Type IV girders while
the 57 ft spans use AASHTO Type III girders. The spacing of both girder
types is 10 ft. The environment is considered a normal bridge over
water. The HPC elements are the girders and deck.

The original design for the replacement bridge utilized six lines of
girders. HPC made it possible to use five lines. In addition, HPC is
expected to improve the durability of the bridge deck resulting in lower
maintenance and life cycle costs. The total cost of the bridge was
\$59.61/ft^2^ of deck surface.

For the deck, the owner allowed the use of Class F fly ash at 20% of
cementitious material weight. The girders used up to 5% silica fume. No
chloride permeability thresholds were specified for the project. The
specifications for both the deck and the girders were performance based.
The contractor was responsible for submitting a mix design that
satisfies the performance parameters. The deck was required to be cured
with burlap and polyethylene sheets kept moist for seven days.

For the girder, the contractor used 911 lb/ft^3^ of cement and 51.2
lb/ft^3^ of silica. For the decks, 593 lb/ft^3^ of cement and 177
lb/ft^3^ of Class F fly ash were used.

***Lessons Learned:*** North Carolina is especially interested in using
HPC as a way to reduce the chloride permeability of its bridge decks.
The specifications for both the deck and the girders are performance
based and the contractor is responsible for submitting a mix design that
satisfies the performance parameters. It is anticipated that his
approach will result in the lowest cost.

Concrete curing temperatures were measured at five cross sections in
Girders A4, B4, C4, and D4. Ten thermocouples were placed at midspan,
three at each quarter span, and three at a distance of span/50 from each
end. Maximum measured concrete temperature was 162 ^o^F.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation.

**11.4.10**[]{#Ohio .anchor} **Ohio**

**U.S. Route 22 near Cambridge**

Opened to traffic in November 1998, U.S. Route 22 over Crooked Creek at
milepost 6.57 near Cambridge in Guernsey County is a 116.5 ft long
bridge. The single span structure utilizes 42 in ODOT box beams spaced
adjacent to each other. The environment is considered a normal bridge
over a road. The HPC elements are the beams and abutments.

High performance concrete was used to replace a three-span non-composite
bridge (using 21-in deep box beams) with a single span structure.
Benefits included reduced substructure costs as well as better flow
characteristics through having an unobstructed channel. The box beams
used 10,000 psi compressive strength concrete and 0.6 in-diameter
prestressing strands. HPC also reduced the permeability of the girders.

For the girders, the owner specified 100 lb/yd^3^ of silica fume and a
water cement ratio of 0.28. For the abutments, 80 lb/yd^3^ of either
Class F(5) fly ash or GGBFS and 88 lb/yd^3^ of silica fume were
specified. Compressive strengths were specified as 10,000 psi at 56 days
for the girders and 8000 psi at 56 days for the abutments. For both the
girders and abutments, chloride permeability of less than 1000 coulombs
was required. Abutment curing consisted of an application of wet burlap
and soaker hoses for seven days. The girders were steam cured for 18
hours.

For the girders, the contractor used 946 lb/yd^3^ of cement and 100
lb/yd^3^ of silica fume. The compressive strengths averaged 11,810 psi
at 56 days. Permeability was as low as 358 coulombs at 56 days. For the
abutments, the contractor used 803 lb/yd^3^ of cement, 75 lb/yd^3^ of
GGBFS, 68.6 lb/yd^3^ of fly ash, and 87.5 lb/yd^3^ of silica fume. An
average compressive strength of 8689 psi was obtained at 28 days.

***Lessons Learned:*** Prior to the construction of the bridge, two
prototype beams were fabricated to determine whether the HPC mix would
perform satisfactory under actual fabrication and service conditions;
allow the fabricator to gain experience with using a HPC mix; and
predict the structural behavior.

The following conclusions were noted from tests conducted on the beams:

1.  Camber at release was 0.25 in which was well below the calculated
    camber of 1 in.

2.  The measured prestress losses, at the time the girders were loaded
    to crack, were 17

> and 18 percent, which compares with 20 percent calculated using the
> AASHTO Standard Specifications.

3.  The cracking moment was 21 percent higher than the cracking moment
    calculated using

AASHTO Standard Specifications.

4.  Measured flexure strengths were four percent greater than the values
    calculated using

the AASHTO Standard Specifications.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation.

[]{#SD1 .anchor}**11.4.11a South Dakota**

> **I-29 Northbound Bridge**

This is a three span precast I-girder bridge on Interstate 29 over a
railroad located in a normal environment. Each span consists of four
AASHTO Type II girders spaced at 11.5 feet. The HPC elements of this
bridge are the precast girders, bent diaphragm and deck.

The use of HPC resulted in reducing the number of girder lines from five
to four and increased deck durability. The average cost for this bridge
was \$48.03 per sq. ft. of deck. This bridge was opened to traffic in
1999.

The girder design was based on a 28-day concrete strength of 9,900 psi
and a concrete strength of 8,520 psi at release. In addition, an air
entrainment of 6.5% was specified for the girders and the deck. The
specified minimum total cementitious material content for the deck was
684 lb./cu.yd. For the girders, the contractors used 680 lb./cu.yd of
Type II cement and 84 lb./cu.yd. of silica fume with a w/c ratio of
0.25. For the deck, the contractors used 511 lb./cu.yd. of cement, 118
lb./cu.yd. of fly ash, and 55 lb./cu. yd. of silica fume. High range
water reducer (A and F) and water reducer (A and F) was used in the
girders and the deck. The w/c ratio for the deck was 0.39.

The girder concrete mix design resulted in an average concrete strength
of 15,900 psi.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-16julaug01.pdf>

[]{#SD2 .anchor}**11.4.11b South Dakota**

**I 29 Southbound Bridge**

This is a three span precast I-girder bridge on Interstate 29 over a
railroad located in a normal environment. Each span consists of four
AASHTO Type II girders spaced at 11.5 feet. The HPC elements of this
bridge are the precast girders, bent diaphragm, and deck.

The use of HPC resulted in reducing the number of girder lines from five
to four and increased deck durability. The average cost for this bridge
was \$56.70 /ft^2^ of deck. This bridge was opened to traffic in 2000.

The girder design was based on a 28-day concrete strength of 9,900 psi
and a concrete strength of 8,520 psi at release. The owners required
that 10% of the cement used in the deck concrete be replaced with Class
F fly ash at a ratio of fly ash to cement of 1.9:1.0 by weight. For the
girders, the contractors used 680 lb/yd^3^ of Type II cement and 84
lb/yd^3^ of silica fume with a w/c ratio of 0.25. For the deck, the
contractors used 590 lb/yd^3^ of cement and 124 lb/ yd^3^ of Class F fly
ash. High range water reducer (A and F) was used for the girders and the
deck. Water reducer (A) was used in the girders. The girders and the
deck had air entrainment. The w/c ratio for the deck was 0.39.

The girder concrete mix design resulted in an average concrete strength
of 13,250 psi.

***Lessons Learned:*** In August 2001, an underside crack survey was
conducted from the ground. Transverse cracks, fairly uniformly
distributed in all the three spans, were observed. Nearly all the cracks
exhibited calcium carbonate precipitation.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-16julaug01.pdf>

[]{#Tennessee .anchor}**11.4.12a Tennessee**

**Hickman Road over State Route 840**

Opened to traffic in September 2000, the Hickman over S.R. 840 bridge in
Dickson County is a 290 ft 8 in long bridge. It consists of two spans
and utilizes 72 in bulb tee girders spaced at 8 ft 4 in. The environment
is considered a normal bridge over a roadway. The HPC elements are the
retaining walls, abutments, bent, girders, and deck.

HPC was used to provide longer span lengths and a more durable
structure. Without the use of HPC, steel girders would have been used at
an additional cost of \$825,000. The cost of the beams, deck concrete,
and substructure concrete was \$160/ft, \$315 lb/yd^3^, and 240 lb/yd^3^
respectively. The total cost of the bridge, excluding pavement at bridge
ends, was \$59/ft^2^.

For the girders, deck, and substructure, the owner allowed the use of
silica fume up to 8% of cementitious material weight. The specified
compressive strengths at 28 days for the girders, deck, and substructure
were 10,000, 5000, and 4000 psi, respectively. The girders used 0.6 in
prestressing strands. Specified chloride permeability at 28 days for the
girders, deck, and substructure was less than 2500, 1500, and 3000
coulombs respectively. The deck was cured with fogging followed by
membrane curing, wet burlap, and vapor barrier.

For the girders, the contractor used 747 lb/yd^3^ of cement and 249
lb/yd^3^ of Class C fly ash. The compressive strengths averaged 10,259
psi at 28 days and 11,249 psi at 56 days. The chloride permeability
averaged 496 coulombs at 56 days. For the deck, the contractor used 496
lb/yd^3^ of cement, 194 lb/yd^3^ of Class C fly ash, and 50.7 lb/yd^3^
of silica fume. An average compressive strength of 7197 psi at 56 days
was obtained. Chloride permeability at 56 days averaged 707 coulombs.

***Lessons Learned:*** Strain and temperatures were measured at 14
locations in each of two girders. The deflection values due to
individual effects of temperature change and truck load were found to be
significantly smaller than the AASHTO limitation of Span/800. This test
clearly demonstrated the role of pile foundation under the abutments in
abutment movement due to temperature change and live load. It was,
however, noted that temperature change has more influence than live
load. The live load distribution coefficients based on the test data
were found to be significantly different from the predicted values, say,
by AASHTO recommended lever rule.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-10julaug00.pdf>

[]{#Tennessee2 .anchor}**11.4.12b Tennessee**

**Porter Road over State Route 840**

Opened to traffic in May 2000, the Porter Road over S.R. 840 bridge in
Dickson County is 318 ft long and 32 ft wide. It consists of two 159 ft
spans and utilizes 72 in bulb tee girders spaced at 8 ft 4 in. The
environment is considered a normal bridge over a roadway. The HPC
elements are the retaining walls, abutments, bent, girders, and deck.

HPC was used to provide longer span lengths and a more durable
structure. Without the use of HPC, steel girders would have been used at
an additional cost of \$825,000. The cost of the beams, deck concrete,
and substructure concrete was \$160/ft, \$315 lb/yd^3^, and 240 lb/yd^3^
respectively. The total cost of the bridge, excluding pavement at bridge
ends, was \$56/ft^2^.

For the girders, deck, and substructure, the owner allowed the use of
silica fume up to 8% of cementitious material weight. The specified
compressive strengths at 28 days for the girders, deck, and substructure
were 10,000, 5000, and 4000 psi, respectively. The girders used 0.6 in
prestressing strands. Specified chloride permeability at 28 days for the
girders, deck, and substructure was less than 2500, 1500, and 3000
coulombs respectively. The deck was cured with fogging followed by
membrane curing, wet burlap, and vapor barrier.

For the girders, the contractor used 747 lb/yd^3^ of cement and 249
lb/yd^3^ of Class C fly ash. The compressive strengths averaged 9651 psi
at 28 days and 10,090 psi at 56 days. The chloride permeability averaged
390 coulombs at 56 days. For the deck, the contractor used 496 lb/yd^3^
of cement, 194 lb/yd^3^ of Class C fly ash, and 50.7 lb/yd^3^ of silica
fume. An average compressive strength of 8265 psi was obtained at 28
days and 8713 psi at 56 days. Chloride permeability at 56 days averaged
1297 coulombs.

***Lessons Learned:*** Strain and temperatures were measured at 14
locations in each of two girders. The deflection values due to
individual effects of temperature change and truck load were found to be
significantly smaller than the AASHTO limitation of Span/800. This test
clearly demonstrated the role of pile foundation under the abutments in
abutment movement due to temperature change and live load. It was,
however, noted that temperature change has more influence than live
load. The live load distribution coefficients based on the test data
were found to be significantly different from the predicted values, say,
by AASHTO recommended lever rule.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the project:

<http://www.cement.org/pdf_files/hpc-10julaug00.pdf>

# **11.4.13a Texas**

**Louetta Road Overpass, Houston**

The Louetta Road Overpass is a multiple span bridge on State Highway 249
and is located in normal environment. Its spans are simply supported
(maximum span length is 135.5 feet) and comprise of six precast Texas US
54 (bath tub) girders, with the girder spacing varying from 11 feet to
over 16 feet. The HPC elements of this bridge include the precast piers,
precast girders and deck panels and cast-in-place (CIP) deck.

The use of HPC increased deck durability and permitted contractors to
utilize preferred methods for bridge construction. The unit cost was
\$24.09/ft^2^ of deck (conventional concrete was \$23.61/ft^2^). This
bridge was opened to traffic in 1998.

The two main requirements were high design strength (9,800 psi to 13,100
psi @ 56 days) and high early strength (minimum 6,000 psi to 8800 psi @
release) for the girders. Neither a permeability requirement for the
deck or any admixture was explicitly specified.

For the HPC girders, the contractors used type III cement (671 lb/yd^3^)
along with 315 lb/yd^3^ of Type C fly ash, at a w/c ratio of 0.25. Type
C fly ash was also used in the deck panels and CIP deck. High range
reducer (Type F) was used in the girders and deck panels and in the CIP
deck (Type F). Type B and D retarders were used in the girders, deck
panels, and CIP deck. The girder concrete strengths (56 day) achieved
varied from 12,170 psi to 14,440 psi.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on evolution of HPC in Texas:

<http://www.cement.org/pdf_files/hpc-30novdec03.pdf>

[]{#Texas .anchor}**11.4.13b Texas**

####  U.S. Route 67 over North Concho River, U.S. Route 87, and 

**South Orient Railroad,** **San Angelo**

The San Angelo Bridge on US Rte 67/87 spans over a river and railroad.
This bridge is a multi-span precast I-girder bridge located in normal
environment. The eastbound (EB) bridge has eight spans (max. 157 ft) and
four girders per span at 11 feet. The westbound (WB) bridge has nine
spans (max. 131 ft) and seven girders per span at 5 ft 8 in. The girders
are predominantly AASHTO Type IV (a few are Texas Type B). The HPC
elements include precast girders and deck panels (EB bridge) and
cast-in-place (CIP) deck (EB and WB bridge).

HPC resulted in a reduced number of spans and girders/span on the EB
bridge and increased deck durability. Average costs were \$42.03 /ft^2^
of deck (EB bridge) and \$45.38 /ft^2^ of deck (WB bridge). The bridge
was opened to traffic in 1998

The owners required a permeability corresponding to a maximum of 1500
coulombs for the decks. The specified concrete strength for the girders
(EB) varied from 12,500 psi to 14,000 psi (56 days). A high early
strength of 8,000 to 8,100 psi (at release) was specified for the EB
bridge. In addition, a minimum of 20% flyash was required if reactive
aggregates were used (maximum flyash was 35%). The concrete mix also
required a 50% ground granulated blast furnace slag (0 % with type IP
cement), and a maximum w/c ratio of 0.49 for girders and 0.44 for deck.

The contractors used 671 lb/yd^3^ of cement (min. specified was 564 lb/
yd^3^) for the HPC. Type C fly ash for the girders and CIP deck was
used. In addition, Type F high range reducers for the girders and EB CIP
deck, and Type D for the deck panels, Type B for the girders, and Type B
and D for the CIP deck were used. The w/c ratio was 0.25 for the girders
and 0.27 for the deck. Girder concrete strengths that were achieved
ranged from 13,830 psi to 15,240 psi.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation or click the link
below to read an HPC Views article on the evolution of HPC in Texas:

<http://www.cement.org/pdf_files/hpc-30novdec03.pdf>

[]{#VirginiaRoute40 .anchor}**11.4.14a Virginia**

#  **Route 40 over Falling River, Brookneal in Lynchburg District**

Opened to traffic in May 1996, Route 40 over Falling River is a 320 ft
long bridge with a 44 ft roadway. There are four 80 ft spans of AASHTO
Type IV girders spaced at 10 ft. The environment is considered a normal
bridge over water. The HPC elements are the substructure, girders, and
deck.

> The 8000-psi concrete compressive strength in the girders enabled the
> use of five lines of girders rather than the seven lines that would
> have been required with a compressive strength of 6000 psi. The total
> cost of the bridge was \$49.32/ft^2^ of deck surface. This was lower
> than the average Federal-aid cost of \$58/ft^2^ for bridges built that
> year. Concrete had to meet low permeability requirements, which are
> expected to result in longer service life with minimal maintenance
> costs.

For the girders, substructure, and deck, the owner allowed the use of
fly ash (20-35%), silica fume (7-10%), and GGBFS (35-50%). The chloride
permeability requirements were 1500 coulombs for the girders, 3500
coulombs for the substructure, and 2500 coulombs for the deck based on
modified (uses a curing procedure of one week at 73 ^o^F and three weeks
at 100 ^o^F) AASHTO T 277 at 28 days. The deck was required to be cured
with wet burlap covered with plastic sheeting for seven days and then
curing compound applied after removal of plastic sheeting and burlap.

For the girder, the contractor used 752 lb/yd^3^ of cement and 55
lb/yd^3^ of silica fume and obtained a chloride permeability of less
than 500 coulombs based on trial batches. For the substructure, trial
batches had permeability of less than 1850 coulombs based on using 353
lb/yd^3^ of cement and 235 lb/yd^3^ of ground granulated blast furnace
slag (GGBFS). For the decks, permeability of around 1100 coulombs at 28
days was obtained using 329 lb/yd^3^ of cement and 329 lb/yd^3^ of
GGBFS.

***Lessons Learned:*** A load test was conducted on one production beam.
The purpose of the test was to determine the amount of residual
deflection in the beam after removal of a maximum load equal to 95
percent of the calculated load to cause a flexural crack. The beam was
considered to be adequate if a recovery of 90 percent or greater was
achieved. The instantaneous recovery was 97.9 percent. At 30 minutes
after removing the load, the recovery was 100 percent. No cracks were
seen in the beam.

> Before initiation of the Route 40 project, an experimental project was
> conducted to support the design of high-strength, low permeability
> beams with 0.6‑in-diameter strands. Four prestressed concrete AASHTO
> Type II beams each containing ten 0.6-in-diameter strands at 2‑in
> center-to-center spacing were fabricated at a prestressing plant and
> tested to failure at the FHWA Structures Laboratory.

Trial batches were prepared at the plant and in the laboratory before
the preparation of actual field concretes for the test beams. Concrete
tests showed that high-strength air-entrained concretes with 28-day
strengths exceeding 10,000 psi and a minimum release strength of
70 percent of the 28-day strengths could be produced with a
water-cementitious materials ratio (w/cm) of about 0.30 or less. To
achieve such low w/cm required high amounts of cementitious material,
proper selection of aggregates, and high dosages of HRWRA. To achieve
high early strengths, proper temperature management was needed. With low
curing temperatures, it is difficult to achieve high early strengths,
but higher ultimate strengths can be achieved. Optimum temperature for
both the early and ultimate strengths could only be determined by trial
batching and testing.

In two of the beams, the temperature within the beam was continuously
monitored by thermocouples embedded prior to casting. During steam
curing, a temperature of 160 ^o^F was planned within the enclosure.
However, the enclosure temperature inadvertently approached 185 ^o^F,
which resulted in concrete temperatures of 219 ^o^F and 208 ^o^F in two
beams. Some of the test specimens stored in the recesses of the forms
exhibited visual cracks attributed to high heat. These specimens
exhibited high variability in strength and some did not meet the
strength requirements due to heat-related damage. However, some of the
specimens had strengths above the requirements.

The beam with high internal temperatures exceeding boiling performed
satisfactory during load testing. All flexural failures were due to
concrete crushing in the outermost fibers of the top flange. The
prestressed beams with 0.6‑in-diameter strands had satisfactory concrete
strengths (exceeding 10,000 psi), and performed as intended under the
loading condition and did not reflect the high variability and
lower-than-desired strengths observed in the test specimens damaged by
heat.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation.

[]{#VirginiaClinch .anchor}**11.4.14b Virginia**

####  Virginia Avenue over Clinch River, Richlands

Opened to traffic in December 1997, Virginia Avenue over Clinch River is
a 148 ft long and 42 ft wide bridge. There are two 74 ft spans of AASHTO
Type III girders spaced at 8 ft 9 in and 9 ft 3 in. The environment is
considered a normal bridge over water. The HPC elements were the girders
and deck.

The original design for the replacement bridge used conventional
concrete and had three spans with seven beams per span. The replacement
bridge uses two spans with five beams per span. The total cost of the
bridge was \$60.43/ft^2^ of deck surface. This was lower that the
average cost of \$69/ft^2^ for similar bridges. Concrete had to meet low
permeability requirements, which are expected to result in longer
service life with minimal maintenance costs.

For the girders and deck, the owner allowed the use of fly ash (20-35%),
silica fume (7-10%), and GGBFS (35-50%). The chloride permeability
requirements were 1500 coulombs for the girders and 2500 coulombs for
the deck based on modified (uses a curing procedure of one week at 73
^o^F and three weeks at 100 ^o^F) AASHTO T 277 at 28 days. The deck was
required to be cured with wet burlap covered with plastic sheeting for 7
days and then curing compound applied after removal of plastic sheeting
and burlap.

For the girder, the contractor used 752 lb/yd^3^ of cement and 75
lb/yd^3^ of silica fume and obtained a chloride permeability of less
than 200 coulombs based on trial batches. For the decks, permeability of
less than 1500 coulombs at 28 days was obtained using 560 lb/yd^3^ of
cement and 140 lb/yd^3^ of Class F fly ash.

> ***Lessons Learned:*** Prior to construction, a test program was
> initiated to develop the desired concrete and to determine the
> structural feasibility of using HPC beams with 0.6-in-diameter strands
> spaced at 2 in. Two full-scale prestressed concrete beams with
> composite deck slabs were fabricated and tested. The beams were tested
> using a concentrated load located at various distances from the beam
> end. The measured cracking load and ultimate load exceed the predicted
> values in all cases. Both measured transfer and development lengths
> were much lower than those predicted by AASHTO equation 9.32

A load test was conducted on one production beam. The purpose of the
test was to determine the amount of residual deflection in the beam
after removal of a maximum load equal to 95 percent of the calculated
load to cause a flexural crack. The beam was considered to be adequate
if a recovery of 90 percent or greater was achieved. The instantaneous
recovery was 98.5 percent. At 30 minutes after removing the load,
recovery was 100 percent. No cracks were seen in the beam.

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation.

[]{#Washington .anchor}**11.4.15a Washington**

**11.4.15a Washington**

**Eastbound lanes of State Route 18 over State Route 516**

**(King County)**

Opened to traffic in March 1998, State Route 18 over State Route 516 is
a 297 ft long 38 ft wide bridge. There are three spans of 80, 137, and
80 ft of WSDOT W74G girders spaced at 8 ft. The environment is
considered a normal bridge over a road. The HPC elements were the
girders and deck.

High performance concrete was specified for the prestressed concrete
girders to improve durability and strength of the concrete. The use of
high-strength concrete allowed the number of lines of girders to be
reduced from seven to five. This resulted in a savings of 594 ft of
girders. The girders cost \$153/linear ft and the deck was built for
\$250,000.

For the girders, the owner specified the use of fly ash (25%) and for
the deck specified 735 lb/yd^3^ of cement and 75 lb/yd^3^ of fly ash.
The chloride permeability requirements were 1000 coulombs for the
girders based on AASHTO T 277 at 56 days and not specified for the deck.
The deck was to be cured with two coats of curing compound and wet cured
using quilted blankets or burlap for 14 days.

For the girder, the contractor used 728 lb/yd^3^ of cement, 222 lb/yd^3^
of fly ash, and 50 lb/yd^3^ of silica fume and obtained a chloride
permeability of around 1000 coulombs. For the decks, permeability of
less than 2800 coulombs at 28 days was obtained using 660 lb/yd^3^ of
cement and 75 lb/yd^3^ of fly ash.

***Lessons Learned:*** Prior to fabricating the production girders, a
20-ft-long test girder was fabricated for the precaster to gain
experience with using the HPC mix and for the researchers to gain
experience installing the instrumentation under field conditions. Some
measurements from the test girders are included in HPC Bridges -- HPC
Data Compilation. Others are available in the "High Performance Concrete
in Washington State SR 18/SR 516 Overcrossing: Final Report on Girder
Monitoring," Washington State Transportation Center, December 2000, by
Barr, P..

For more detailed information, [click to visit the HPC Exchange Web
site](http://knowledge.fhwa.dot.gov/cops/hpcx.nsf/Documents) to view
files from the HPC Bridges -- HPC Data Compilation.

# **11.5 References**

1.  Symposium Proceedings, PCI/FHWA International Symposium on High
    Performance Concrete, New Orleans, LA,, Precast/Prestressed Concrete
    Institute, Chicago, IL, 1997.

2.  Symposium Proceedings, PCI/ FHWA/fib International Symposium on High
    Performance Concrete, Orlando, FL, Precast/Prestressed Concrete
    Institute, Chicago, IL, 2000.

3.  SHRP High Performance Concrete Bridge Showcase Notebook, Houston,
    TX, March 25-27, 1996.

4.  SRP High Performance Concrete Regional Showcase Notebook, Omaha, NE,
    November 18-20, 1996.

5.  SHRP High Performance Concrete Bridge Showcase Notebook, Richmond,
    VA, June 24-26, 1997.

6.  SHRP High Performance Concrete Bridge Showcase Notebook, Belleview,
    WA, August 18-20, 1997.

7.  SHRP High Performance Concrete Bridge Showcase Notebook, Waterville
    Valley, New Hampshire, September 22-23, 1997.

8.  Colorado High Performance Concrete Showcase Notebook, Denver, CO,
    February 18-20, 1998.

9.  SHRP High Performance Concrete Bridge Showcase Notebook, Cincinnati,
    OH, February 23-24, 1999.

10. Southeast Regional High Performance Concrete Showcase Notebook,
    Auburn, AL, June 29-July 1, 1999.