Introduction

Advancements in the science of concrete 

materials have led to the development of a 

new class of cementitious composites called 

ultra-high performance concrete (UHPC). UHPC 

exhibits mechanical and durability properties 

that make it an ideal candidate for use in developing new solutions to pressing concerns about 

highway infrastructure deterioration, repair, 

and replacement.(1,2) Field-cast UHPC details 

connecting prefabricated structural elements 

used for bridge construction have proven to be 

an application that has captured the attention 

of owners, specifiers, and contractors across 

the country. These connections can be simpler to construct and can provide more robust 

long-term performance than connections constructed through conventional methods.(3) This 

document provides guidance on the design and 

deployment of field-cast UHPC connections.

UHPC

UHPC is a fiber-reinforced, portland cementbased product with advantageous fresh and 

hardened properties. Through the appropriate 

combination of advancements in superplasticizers, dry constituent gradation, fiber reinforcements, and supplemental cementitious 

materials, UHPC is able to deliver performance 

that far exceeds conventional concrete. 

Developed in the late 20th century, this 

class of concrete has emerged as a capable 

replacement for conventional structural materials 

in a variety of applications.

The Federal Highway Administration (FHWA) 

defines UHPC as follows:

UHPC is a cementitious composite material 

composed of an optimized gradation of granular constituents, a water-to-cementitious 

materials ratio less than 0.25, and a high 

percentage of discontinuous internal fiber 

reinforcement. The mechanical properties 

of UHPC include compressive strength 

greater than 21.7 ksi (150 MPa) and sustained 

post-cracking tensile strength greater than 

0.72 ksi (5 MPa).1

 UHPC has a discontinuous 

pore structure that reduces liquid ingress, 

significantly enhancing durability compared 

to conventional concrete.(2)

Research, Development, and Technology

Turner-Fairbank Highway Research Center

www.fhwa.dot.gov/research 6300 Georgetown Pike, McLean, VA 22101-2296

FHWA Publication No: FHWA-HRT-14-084

FHWA Contact: Ben Graybeal, HRDI-40, 202-493-3122, benjamin.graybeal@dot.gov

TECHNOTE

Design and Construction of 

Field-Cast UHPC Connections

TABLE OF CONTENTS:

Common Connections .................................4

Design Guidance ........................................11

Specifying UHPC........................................17

Construction Engineer Inspection ............25

Case Study ..................................................27

Deployments...............................................32

1

The tensile behavior of UHPC may generally be defined as “strain-hardening,” a broad term defining concretes in which the sustained 

post-cracking strength provided by the fiber reinforcement is greater than the cementitious matrix cracking strength. Note that the postcracking tensile strength and strain capacity of UHPC is highly dependent on the type, quantity, dispersion, and orientation of the internal fiber 

reinforcement. 
2

Constituents

Like conventional concrete, UHPC is composed 

of a variety of constituents that are combined 

together in a mixer to create a semifluid product that can be placed into formwork and, with 

time, will develop a particular set of properties. 

The common constituents of UHPC include 

dry components, fiber reinforcement, chemical 

admixtures, and water. Because UHPC, like conventional concrete, is defined by the properties 

of the composite material, multiple formulations 

may produce similar characteristics.(4) The following information on constituents speaks to 

common UHPC formulations.

As with all concretes, UHPC formulations must 

be developed with a focus on a range of performance considerations. Compatibility of constituent components is a key consideration. Exact 

compositions, particle geometry, and reactivity 

may vary. Any modifications of existing mix 

designs or products through the addition or 

subtraction of constituents should be completed with care.

Dry Components

Dry components comprise the majority of the 

UHPC constituents. These components include 

portland cement, silica fume, and fine aggregates. UHPC formulations may also include 

small coarse aggregates and supplementary 

cementitious materials. 

A variety of portland cements are produced in 

the United States, each performing in a specific 

way. The portland cement used in UHPC may 

be produced to meet the standards of ASTM 

C150 and/or American Petroleum Institute 

Specification 10A.(5,6) Class H oil well cements 

are frequently included in UHPC mix designs.

Silica fume is a key component in UHPC 

because of its reactivity and its small particle 

size. UHPC commonly includes a high proportion of silica fume (10 percent or more relative 

to the weight of cement).

The fine aggregates are proportioned and 

sized to allow a gradation of dry constituents 

that facilitates flowability in the fresh UHPC. A 

variety of fine aggregates can be appropriate 

for use in UHPC, including quartz, limestone, 

and basalt.

Coarse aggregates are sometimes included in 

UHPC formulations. These aggregates tend to 

be relatively small (1⁄4 inch (6 mm) or less) and 

included at low proportions compared with 

conventional concrete.

Other supplementary cementitious materials—

including fly ash, metakaolin, ground granulated blast furnace slag, and limestone 

powder—have been considered for inclusion in 

UHPC formulations.

The dry components of the cementitious composite are available from a wide variety of 

sources. Exact chemical compositions, particle 

geometry, and reactivity may vary, so developers of UHPC mix designs are advised to 

consider compatibility issues, fresh concrete 

properties, and hardened concrete properties.(4)

Chemical Admixtures

The types of chemical admixtures used in UHPC 

are readily available in the concrete industry. 

These admixtures commonly include accelerators, polycarboxylate-based superplasticizers, and phosphonate-based superplasticizers. Other admixtures could also be used 

in support of a specific need on a particular 

project. These chemicals are proportioned 

according to the project requirements to provide 

the thixotropic, self-consolidated properties 

of the UHPC in the unhardened state and to 

encourage specific post-placement material 

behaviors. Because of the broad availability of 

these types of admixtures, these products do 

not normally raise concerns with regard to use 

of proprietary products on publically funded 

construction projects.

Water

The cementitious reaction that is inherent to 

the use of portland cement-based composites 

requires an adequate supply of potable water. 

Common requirements for water quality and 

water control relative to conventional concrete 

are also applicable to UHPC. 
3

The temperature of the water during its addition to the mixer has been demonstrated to play 

a key role in achieving appropriate fresh properties. Chilled water and/or ice are commonly 

used to reduce the temperature of the UHPC 

during mixing and placement. This temperature 

reduction facilitates an increase in the fluidity of 

the mix and a reduction in the rate of free water 

evaporation from the mixed UHPC. In addition, 

cubed ice has been demonstrated to increase 

the efficiency of the mixing process by providing 

both increased mixing action in the powder-rich 

UHPC formulations and a sustained supply of 

water throughout the mixing process as the ice 

melts. All ice should be melted before the addition 

of the steel fiber reinforcement.

Steel Fiber Reinforcement

Steel fiber reinforcement is a critical component of UHPC when used in structural elements or field-cast structural connections. 

The exceptional mechanical properties of 

UHPC can be largely attributed to the fiber 

reinforcement. These properties cannot 

be achieved without inclusion of specific 

fibers that afford appropriate fiber efficiency 

to the composite matrix. Fiber efficiency 

is influenced by the fiber type, geometry, 

volume fraction, dispersion, and orientation. 

Both mix design and casting technique contribute to the final mechanical performance.

A UHPC mix design or product must include 

specific information regarding fiber type, geometry, and volume fraction. The cementitious 

composite formulation is commonly designed 

in conjunction with the fiber reinforcement 

constituent to deliver the requisite fresh and 

hardened properties.

The field-cast UHPC connections described in 

this document require steel fiber reinforcement 

included at very high volumes as compared to 

conventional fiber reinforced concretes. The 

fiber proportion by volume is normally 2 percent 

of the volume of the overall UHPC composite. 

Steel fiber reinforcement provides superior 

crack-bridging capabilities compared with other 

lower-stiffness fiber reinforcements. The steel 

fibers are typically made of high-strength steel 

to ensure that fiber tensile failure does not 

occur. Fibers may be straight or deformed. 

The most common steel fiber deployed in UHPC 

applications is a 0.008-inch (0.2-mm) diameter 

by 0.5-inch (13-mm)-long straight fiber with a 

specified minimum tensile strength of 290 ksi 

(2,000 MPa), which is shown in figure 1. 

Domestic production of this type of fiber is 

available for projects that must adhere to the 

Buy America provisions of Federal law.

Availability of UHPC

The sophistication of the UHPC cementitious 

composite, when compared with conventional concrete, has led to the development 

of a worldwide network for the production 

and distribution of preblended UHPCs. 

Typically, multinational construction-materials 

suppliers produce a set of products in 

this class. The dry constituents, chemical 

admixtures, and steel fiber reinforcement 

are delivered to the project site, where they are 

mixed with water to produce the fresh UHPC. 

This production and distribution model is 

similar to the one commonly used for many of 

the proprietary grouts and patching materials 

frequently deployed in the construction of 

public infrastructure. 

Figure 1. Commonly used steel fiber reinforcement.
4

FHWA released a memorandum on the topic 

of UHPC on February 12, 2014.(7) This memo 

addressed the topics of domestic supply of 

steel fiber reinforcement as well as proprietary 

product considerations. The memo also included two attachments. Attachment A provides the New York State Department of 

Transportation (NYSDOT) UHPC specification dated April 19, 2013. Attachment B, titled 

NYSDOT UHPC Implementation Notes, speaks 

to specific applications and considerations 

from the perspective of the owner. 

Individuals and owners considering the 

use of UHPC for field-cast connections 

are encouraged to consult this memo.

UHPC Material Properties

The material properties of a widely available, 

preblended UHPC have been independently 

assessed through a series of research projects 

completed by FHWA. (See references 8, 9, 

10, and 11.) When deployed with 2 percent by 

volume steel fiber reinforcement and cured 

in field-type conditions, this UHPC has been 

observed to exhibit the properties provided in 

table 1. 

Common UHPC Connection 

Concepts

Opportunities to modify and improve upon 

prefabricated element connection details 

exist by taking advantage of the material and 

durability properties that UHPC has to offer. 

In addition to the high compressive and 

post-cracking tensile strengths, the dense, 

discontinuous pore structure and steel fiber 

reinforcement of UHPC provide further material 

property benefits. Improvements include better 

internal distribution of stresses, better confinement of embedded rebar, and reduced rebar 

development and splice lengths. 

UHPC Lap Splices—Adjacent Precast Deck 

Panel Connections

The simplest and most common connection 

detail involves the lap splicing of mild steel 

reinforcing bars. For rebar in tension, the current American Association of State Highway 

and Transportation Officials (AASHTO) Load 

and Resistance Factor Design (LRFD) Bridge 

Design Specifications require a minimum 

development length of at least 24 times the 

bar diameter (db).(12) Frequently, the length can 

be 36db or larger. Long lap lengths may lead 

to undesirably large connections; alternatives 

include using hoops, hooks, headed rebar, or 

mechanical couplers. 

For rebar embedded in UHPC, the tension 

development length is a fraction of the length 

needed in conventional concrete. As a result, 

structural elements can be connected to 

each other by shorter, straight lengths of 

rebar in connections that are significantly less 

complicated than those that use conventional 

concrete or grout.(13) Reinforcement costs, difficulties in fabrication, and field assembly are 

all factors that can be improved by specifying 

field-cast, lap-splice connections with UHPC. 

Connections between precast bridge deck panels are one example of a field-cast lap joint that 

takes advantage of UHPC. Rebar from one panel 

overlaps with the rebar from the other adjacent panel, and the void between them is filled 

with UHPC. The connection transfers moment, 

shear, and tensile forces across the joint using 

short, straight rebar spaced at intervals typical 

to conventional deck design.

One example of this connection is shown in 

figure 2. This connection detail was used in a set 

of bridges constructed on I-81 in Syracuse, NY, 

in 2013. This illustration shows the transverse 

connection detail between adjacent panels, in 

which the top and bottom mats of reinforcement are lap spliced within a 6-inch (152-mm)-

wide connection.

Another example of this deck connection 

is shown in figure 3. This detail was used 

during the reconstruction of a bridge on 

County Road 47 (CR47) over Trout Brook 

near Stockholm, NY. No. 5 epoxy-coated 

reinforcing bars spaced at 12 inches (305 mm) 

in the top and bottom mats were lap spliced. 

The connections were specified to be 8 inches 

(203 mm) wide, with a minimum 6-inch 

(152-mm) lap splice. The additional 2-inch 

(51-mm) width allows the panels to 

accommodate in-field tolerances associated 

with panel placement. By keeping the connection 
5

width small, this detail addresses field 

fit-up tolerances, minimizes the volume of 

UHPC material to be mixed and placed, and 

requires only simple formwork to create the 

connection. A final example of this deck-level 

connection is shown in figure 4. This detail 

was used during the reconstruction of a bridge 

on U.S. Route 30 over the Burnt River and the 

Union Pacific Railroad near Huntington, OR. 

The detail included epoxy-coated No. 5 bars 

in the top and bottom mats. The bars were 

specified to have a 6-inch (152-mm) lap length 

within a 6-inch (152-mm)-wide female–female 

shear key connection.

Material Characteristic Average Result

Density 155 lb/ft3

 (2,480 kg/m3) 

Compressive strength (ASTM C39; 28-day strength) 24 ksi (165 MPa)

Modulus of elasticity (ASTM C469; 28-day modulus) 7,000 ksi (48 GPa)

Direct tension cracking strength (uniaxial tension with multiple cracking) 1.2 ksi (8.5 MPa)

Split cylinder cracking strength (ASTM C496) 1.3 ksi (9.0 MPa)

Prism flexure cracking strength (ASTM C1018; 12-inch (305-mm) span) 1.3 ksi (9.0 MPa)

Tensile strain capacity before crack localization and fiber debond > 0.003

Long-term creep coefficient (ASTM C512; 11.2 ksi (77 MPa) load) 0.78

Long-term shrinkage (ASTM C157; initial reading after set) 555 microstrain

Total shrinkage (embedded vibrating wire gage) 790 microstrain

Coefficient of thermal expansion (AASHTO TP60–00) 8.2 x10–6 inches/inches/oF

(14.7 x10–6 mm/mm/oC)

Chloride ion penetrability (ASTM C1202; 28-day test) 360 coulombs

Chloride ion permeability (AASHTO T259; 0.5-inch (12.7-mm) depth) < 0.10 lb/yd3

 (< 0.06 kg/m3)

Scaling resistance (ASTM C672) No scaling

Abrasion resistance (ASTM C944 2x weight; ground surface) 0.026 oz. (0.73 g) lost

Freeze-thaw resistance (ASTM C666A; 600 cycles) RDM = 99 percent

Alkali-silica reaction (ASTM C1260; tested for 28 days) Innocuous

AASHTO = American Association of State Highway and Transportation Officials

RDM = relative dynamic modulus of elasticity

Table 1. Typical field-cast UHPC material properties.
6

Figure 4. Precast deck panel for use with UHPC connections as deployed by the Oregon Department of 

Transportation (ODOT) on U.S. Route 30 near Huntington, OR.

Figure 2. UHPC connection between precast deck panels as deployed by NYSDOT on I-81 in Syracuse, NY.

Figure 3. UHPC connection between precast deck panels as deployed by NYSDOT on CR47 over Trout Brook.
7

UHPC Connections for Composite Action—

Precast Deck Panel to Girder Details

The conventional detail to connect prefabricated deck panels to girders requires 

the use of shear studs or rebar extending 

from the girder into block-out pockets in the 

deck that are filled with grout to create a composite deck/beam structure. The placement 

of the block-out pockets may cause clearance 

challenges with rebar and other associated 

hardware (post tensioning, lifting lugs, leveling 

bolts, drainage assemblies, etc.) during panel 

fabrication. For certain bridge configurations, 

the large number of shear connectors required 

may result in congested or even unworkable 

block-out pocket configurations. Deck overlays, 

which require an additional construction 

activity, are typically installed over prefabricated deck panels to address concerns about 

water ingress through the cold joint between 

the precast panel and shear stud pocket. 

Overlays are also used to address the long-term 

performance and wearability concerns 

regarding conventional grout surfaces in direct 

contact with repeated wheel loadings.

Details that use UHPC can improve the conventional block-out pocket detail. Congestion 

issues associated with the rebar and hardware used in the prefabricated panel can be 

addressed through a reconfiguration of the 

conventional shear pocket concept. Elimination 

of a deck overlay can also become a viable 

option because of UHPC’s good bonding 

ability to adjoining precast surfaces and the 

discontinuous pore structure that nearly 

eliminates liquid ingress. The thixotropic, selfconsolidating properties allow UHPC to flow 

into tight spaces, thus offering the opportunity 

for a continuous, hidden connection detail that 

eliminates the conventional shear pocket detail 

altogether. UHPC also has the ability to improve 

internal stress distribution, thus enhancing the 

composite action between the prefabricated 

panel and supporting beam.

This connection concept has begun to be 

deployed in the U.S. bridge inventory in a series 

of bridges in New York State on roadways ranging from county routes to interstate highways. 

In each of these slab-on-stringer bridges, the 

height of the shear connectors remains below 

the bottom mat of deck panel rebar to simplify 

the deck panel installation. Inherent in this 

concept is the reliance on the UHPC to carry 

the tensile, compressive, and shear stresses 

between the deck and girder connectors.

One example of this connection detail is shown 

in figure 5. This detail was deployed on a series 

of interstate highway bridges near Syracuse, 

NY. The detail combines the panel-to-panel 

connection detail with the deck-to-girder 

connection detail into a single casting of fieldcast UHPC connection that runs along the 

girder line.

Another example of this connection detail is 

shown in figure 6. This detail is the hidden 

pocket version of the detail in which a continuous pocket is created above the girder line and 

then filled with field-cast UHPC. Composite 

action is generated through transfer of forces 

between the girder and the deck through the 

UHPC. This detail was deployed on the CR47 

Bridge over Trout Brook near Stockholm, NY.

A final example of this detail is shown in 

figure 7 with a concrete girder that demonstrates a similar hidden pocket concept to that 

shown in figure 6. Although the configurations 

in figure 6 and figure 7 have been laboratory 

tested and demonstrate adequate structural 

performance under fatigue, service, and 

strength loadings, the detail in figure 7 has yet 

to be deployed in the U.S. bridge inventory.

The concept of creating a hidden composite 

connection through the use of a highly flowable 

grout also can be used without relying 

on the UHPC to carry the shear forces 

between the deck and the girder. Whether 

using UHPC or a conventional grout, the 

connectors extending from the girders can be 

detailed to terminate above the bottom mat of 

rebar in the deck. This detail is virtually identical to the detailing inherent in traditional 

cast-in-place bridge deck construction. 

However, the grout must flow into and fill the 

connection void space during construction.
8

Figure 6. UHPC composite connection between deck panel and steel girder.

Figure 5. Combined UHPC deck-level and composite connections as deployed by NYSDOT on I-81 near 

Syracuse, NY.
9

UHPC Connection for Adjacent Box Beams and 

Other Longitudinal Elements

UHPC connection details have also been developed for use in adjacent box beam bridges. 

Conventional connection details include 

grouted shear keys and intermittent transverse 

post-tensioning. These traditional details have 

often exhibited poor performance, resulting in 

differential deflection between beams, overlay 

cracking, water ingress, and eventually connection failure. 

Similar to the deck-level connections between 

precast concrete bridge deck panels, field-cast 

UHPC connections that bond to the precast interfaces and use a lap-splice reinforcement detail 

can create an improved structural connection 

that is capable of transferring shear, moment, 

and axial tensile/compressive forces across 

the connection. The UHPC detail eliminates 

the need for transverse post-tensioning or a 

structural concrete overlay. In effect, this detail 

creates a continuously reinforced concrete slab 

at the top flange level of the boxes.

The Sollars Road Bridge over Lees Creek in 

Fayette County, OH, is the first box beam bridge 

in the United States to use this UHPC detail. 

This 61-ft (18.6-m) span bridge contains seven 

adjacent box beams. The prestressed boxes are 

4 ft (1.2 m) wide and 21 inches (533 mm) deep 

with 7-inch (178-mm)-deep shear keys on either 

side. Because no transverse post-tensioning is 

required, these boxes did not require intermediate diaphragms. Figure 8 shows the connection 

detail in which adjacent box beams would be 

butted together and the reinforcing bars would 

lap within the connection.

This detail is also applicable to other types of 

decked girder bridge systems. The detail could 

easily be applied to the flange tips of deck-bulbtee girders, Northeast Extreme Tee (NEXT) 

beams, and pre-topped steel modular units. 

This detail lends itself to top-down construction 

in which access to the underside of the superstructure is limited or unavailable.

UHPC Detail for Link Slab Connections

Another potential application of field-cast UHPC 

connections is with link slabs above the interior 

supports of multi, simple-span bridge structures. The intent of the connection is to eliminate the need for strip seals or other traditional 

Figure 7. UHPC composite connection between deck panel and concrete girder.
10

Figure 8. UHPC adjacent box beam connection detail.

joint systems by creating a durable structural 

element spanning between the adjacent bridge 

decks. 

NYSDOT has used this connection detail during the deck reconstruction of the SR962G 

bridge over U.S. Route 17 in Owego, NY. 

The link slab detail is illustrated in figure 9 

via a split-section view with the left side at 

the girder line and the right side midway 

between girders lines. This project used precast concrete deck panels and field-cast UHPC 

lap-splice connections. The composite connection 

detail was a hidden pocket with a conventional 

fluid grout. The link slab detail connects the two 

simple spans of the bridge above the intermediate pier. The bearings under the steel girders 

at the connection are designed to allow both 

rotation and longitudinal movement, thus 

minimizing the negative moments transferred 

between spans and the forces imparted to the 

connection. It is expected that if any cracking were to occur in this detail, then it would 

be tightly spaced and would limit any water 

ingress to the structure elements below. 

Figure 9. UHPC link slab connection detail on SR962G bridge in Owego, NY, shown as split section with left 

side at the girder line and right side midway between girder lines.
11

Design of Field-Cast UHPC Connection Details

The following section provides guidance for the structural design of UHPC connection details. 

This guidance is based on concrete materials and structural engineering research that has been 

conducted on UHPC-class materials. Guidance is provided in the left column while corresponding 

commentary is provided in the right column.

Guidance Commentary

The minimum embedment length of deformed 

steel reinforcement, ld, shall be taken as 8db

for No. 8 bar and smaller with fy (yield strength 

of reinforcing bars) less than or equal to 75 ksi 

(517 MPa) when the following conditions are 

met:

• Field-cast UHPC with 2-percent (by volume) 

steel fiber reinforcement and a compressive 

strength of at least 14 ksi (97 MPa). 

• Cover ≥ 3db.

Research has demonstrated that deformed 

steel reinforcement can be developed within 

comparatively short embedment lengths.(14) An 

embedment length of 8db is sufficient for most 

common reinforcement configurations, including the use of epoxy-coated reinforcement. 

Increased confinement of the bar, increased 

compressive strength of the UHPC, and/or 

decreased bar stress demand can allow shorter 

embedment lengths. 

A compressive strength of 14 ksi (97 MPa) 

is defined here to facilitate use of UHPC in 

accelerated construction when early application of construction loads to newly completed 

connections is advantageous. The final compressive strength of UHPC is normally greater 

than 22 ksi (152 MPa).

The minimum embedment length of deformed 

steel reinforcement meeting the above conditions with 75 ksi (517 MPa) < fy ≤ 100 ksi (689 MPa)

 shall be taken as 10db.

The increased stress and strain demand of 

high-strength reinforcement necessitates an 

increase in the embedment length. 

The minimum embedment length of deformed 

steel reinforcement with fy ≤ 100 ksi (689 MPa) 

and with 2db ≤ minimum cover < 3db shall be 

increased by 2db.

A decrease in the cover results in reduced confinement of the bar and thus an increase in the 

embedment length.

Embedment Length of Deformed Steel Reinforcement
12

Guidance Commentary

Connections between prefabricated bridge elements shall be designed to develop the yield 

strength of the deformed steel reinforcement 

bars extending from the prefabricated concrete 

elements. 

Development of reinforcing bars can be provided through sufficient embedment length, 

through bar hoops/hooks/heads, or through 

mechanical couplers. Given ld, it is commonly 

cost effective and practical to develop deformed 

steel reinforcement through a straight length of 

embedded bar.

For lap splices of straight lengths of deformed 

steel reinforcement, the lap-splice length, ls, 

shall be at least 0.75ld. 

Research has demonstrated that passive reinforcement embedded ld into a connection and 

spliced with adjoining bars to have a lap of 

0.75ld can sustain static and cyclic loads that 

cause rupture of the reinforcing bar outside of 

the connection.(13,14) 

Clear spacing to the nearest lap-spliced bar 

should be less than or equal to ls. Clear spacing 

between adjacent bars must also meet the 

clear spacing requirement defined in Minimum 

Spacing of Reinforcing Bars.

Deformed bars extending from precast 

elements shall be detailed to account for 

tolerances associated with field installation of 

components throughout the structure.

Precast component interfaces onto which the 

field-cast UHPC will bond shall be detailed 

to include female–female shear keys for deck 

panel to deck panel installations.

This shear key detail facilitates compression 

strut transfer of applied loads without relying 

on dowel action of reinforcing bars. It also can 

provide added embedment length for reinforcing bars and added interface area for enhanced 

interface bond.

Precast component interfaces onto which the 

field-cast UHPC will bond shall be specified to 

include roughened interfaces.

Closure Pour Connections Between Prefabricated Bridge Elements
13

Guidance Commentary

The interface connection detail between prefabricated bridge decks and prefabricated girders includes design of the connectors attached 

to the girder and the design of the remainder 

of the connection. The design of the connectors attached to the girder shall be completed 

according to the provisions of AASHTO LRFD 

Bridge Design Specifications 5.8.4 and 6.10.10 

with the following exception:

• Provisions of 6.10.10.1.4 and 5.8.4.4 may be 

superseded if the following conditions are 

met:

o The UHPC contains at least 2 percent (by 

volume) steel fiber reinforcement. 

o The vertical clear distance from top of the 

girder shear connectors to the bottom 

of the deck shear connectors is less than 

3 inches (76 mm). 

o The cyclic shear stress on the minimum 

interface shear plane under service loading 

is less than 0.150 ksi (1 MPa).

o The static shear stress on the minimum 

interface shear plane under strength loading is less than 0.750 ksi (5 MPa).

Research has demonstrated that field-cast 

UHPC with 2-percent (by volume) steel fiber 

reinforcement is capable of carrying shear 

stresses through the UHPC without the aid of 

passive reinforcement. This concept allows the 

elimination of conflict points between the passive connectors on the deck and the girder. An 

exposed bottom mat of deck reinforcement 

above the girder line can be engaged by the 

field-cast UHPC. Shear stress calculations on 

the UHPC must consider the minimum shear 

section of the UHPC.(15)

Interfaces of precast concrete components 

shall be intentionally roughened to a 0.25-inch 

(6.4-mm) amplitude.

Roughening of precast concrete interfaces 

allows increased UHPC bond at the interface 

and reduces the local interface shear stresses 

carried by the discrete steel reinforcement 

crossing the interface

Flow of field-cast UHPC within connection 

details shall be limited to 10-ft (3-m) lengths.

UHPC has been demonstrated to be capable of 

flowing at least 10 ft (3 m) within a haunch connection detail. Long flow distances around discrete reinforcements can interrupt the dispersion 

of the fiber reinforcement, which could reduce the 

mechanical resistance of the UHPC.

Interface Shear Connection Between Prefabricated Bridge Deck and Supporting Girder
14

Guidance Commentary

Ducted substructure connections shall be 

detailed to fully develop the ultimate strength of 

the embedded deformed steel reinforcing bar. 

Failure modes to consider include bar pullout 

from field-cast UHPC, duct pullout from conventional concrete, conventional concrete conical failure around duct, and bar rupture.

The development of deformed reinforcing bars 

commonly used as longitudinal reinforcement 

in substructure components can be completed 

in shorter distances when embedded in fieldcast UHPC contained in ducted connections. 

Static and seismic testing has demonstrated 

the emulative nature of these connections.(16)

Tests were completed on field-cast UHPC with 

2-percent (by volume) steel fiber reinforced, 

compressive strengths above 19 ksi (131 MPa), 

and bar sizes ranging from No. 8 to No. 11. 

Appropriate detailing of the duct and the surrounding precast concrete are critical to the 

overall performance of the connection system.

The embedment length for No. 8 to No. 11 

deformed steel reinforcing bars shall be at least 

8db. This length is exclusive of any debonded 

length. 

Research has demonstrated No. 8 and No. 11 

deformed steel bars can develop a stress 

exceeding 70 ksi (483 MPa) with 3db of embedment into a 4db or less diameter duct. 

Ducts must be corrugated and composed of 

galvanized steel. Duct minimum inside diameter 

may not be more than 4db.

For seismic design, reinforcing bars shall be 

debonded a minimum of 4db into each component above and below the component mating 

interface.

Debonding is necessary to avoid strain concentrations in the precast concrete adjacent to the 

component mating interfaces under seismic 

loading.

Ducted Substructure Connection Detail

Guidance Commentary

Clear spacing between adjacent discrete reinforcements around which UHPC must flow during casting shall be at least 1.5 times the length 

of the longest fiber reinforcement in the UHPC.

Tight spacing of discrete reinforcements can 

restrict the flow of UHPC during casting and 

can impede the uniform distribution of fiber 

reinforcement throughout the component. 

The contact lap splicing of two reinforcing 

elements in combination with the allowance 

for appropriate adjacent clear spacing is 

acceptable practice.(17) 

Minimum Spacing of Reinforcing Bars
15

Mechanical Properties of UHPC: Modulus of Elasticity

Mechanical Properties of UHPC: Cracking Tensile Strength

Guidance Commentary

The modulus of elasticity of UHPC may be 

calculated as follows:

Ec = 49000 √fc ́ in psi units (1) 

Ec = 1550 √fc ́ in ksi units (2)

These equations are based on research results 

obtained from the testing of steel fiber reinforced UHPC with compressive strengths 

between 14 and 26 ksi (97 and 179 MPa).(9)

The relationship presented in AASHTO 

LRFD Bridge Design Specifications 5.4.2.4 

is limited to concrete strengths of 15 ksi 

(104 MPa) and should not be used for UHPC 

because it may overestimate the stiffness of 

the concrete.

Guidance Commentary

The cracking tensile strength of UHPC may be 

calculated as follows:

ft,crack = 0.04 fc ́ (3) 

This equation is based on limited research 

results obtained from the direct and indirect 

tensile testing of strain hardening steel fiber 

reinforced UHPCs with compressive strengths 

between 12 and 30 ksi (83 and 207 MPa).(8,10)

The tensile response of a UHPC matrix may 

develop more rapidly than the compressive response, thus leading to proportionally 

higher tensile strengths at lower compressive 

strengths. 

The cracking and sustained post-cracking 

tensile strengths of the type of strain hardening UHPC formulations commonly deployed 

in the United States has been observed to be 

between 1,000 and 1,500 psi (6.9 to 10.3 MPa). 

This tensile response is highly dependent on 

the efficiency of the steel fiber reinforcement.

Guidance Commentary

Interface surface preparations have a significant 

influence on interface bond strength. Rough 

surfaces with ample macro- and micro-texture 

provide extra bonding area and enhanced 

bond strength. In order of bond strength from 

high to low are exposed aggregate interface, 

sandblasted interface, and as-cast interface.

Quantitative values have not yet been determined; however, qualitative resistance levels 

have been identified.

Prewetting the precast interface with water to 

a saturated surface dry (SSD) has been demonstrated to increase the strength of the bond.

Application of bonding agents or adhesives 

to the precast interfaces may enhance bond 

strength; however, field application of these 

substances may present practical challenges 

that preclude their use.

Mechanical Properties of UHPC: Interface Tensile Bond Strength
16

Guidance Commentary

The density of UHPC inclusive of the steel 

fiber reinforcement may be taken as 155 lb/ft3

(2,480 kg/m3).

This value most closely represents the density of UHPC with 2-percent (by volume) steel 

fiber reinforcement. Lesser or greater percentages of steel fiber reinforcement necessarily 

decrease or increase the density. Inclusion of 

non-steel fiber reinforcement also affects the 

density.

Guidance Commentary

The diffusion coefficient of UHPC may be taken 

as 2.0 x 10-10 in2/s (1.3 x 10-13 m2/s).

This value is based on research completed on UHPC cementitious matrices with 

cementitious materials contents greater 

than 1,500 lb/yd3 (890 kg/m3), no aggregates 

larger than a fine sand with an average 

diameter of 0.02 inches (0.5 mm), and waterto-cementitious materials ratios less than 0.25. 

(See references 17, 18, 19, and 20.)

Physical Properties of UHPC: Density

Physical Properties of UHPC: Chloride Ion Diffusion Coefficient
17

Specifying UHPC

Use of UHPC requires the development of 

material and construction specifications. The 

material specifications define the constituent 

properties, testing criteria, testing levels, and 

payment criteria. The construction specifications provide guidance on field-related activities such as material storage, adequacy of formwork, mixing, in-field testing, placement, and 

curing.

Common to both the material and construction 

specifications is the need to identify project 

specific criteria that may necessitate alterations 

of the UHPC formulation, mixing process, placing process, or curing process. Successful performance of UHPC connections requires that 

each stage of construction be completed in a 

timely and appropriate manner. The owner, the 

material supplier, the inspectors, and the contractor must work together to ensure success. 

Materials Specifications for UHPC

For a public sector agency, specifying the material portion of UHPC follows either a proprietaryor performance-based method. Regardless of 

the specification method, the material specification should identify certain material tests that 

must be completed in the field and in the laboratory to ensure that the UHPC meets project 

requirements.

Proprietary Material Specification Method

The proprietary method of material specification identifies a list of acceptable products by 

name. Products are submitted to the agency by 

suppliers for a particular application, and these 

products perform according to published literature that is based on previously conducted test 

results. 

In many jurisdictions, a proprietary-based 

product can only be used if it undergoes the 

agency’s appropriate acceptance testing protocols and is placed on a pre-approved materials/

products list. Sometimes an “approved equal” 

provision is included in the contract plans to 

allow unidentified suppliers an opportunity to 

demonstrate whether their product meets the 

criteria of the contract plans and specifications. 

Suppliers are typically responsible for maintaining certifications as prescribed by the agency’s 

procurement criteria. 

The following list is not meant to be all 

inclusive, but does provide examples of proprietary products whose material properties 

may align with the needs of a particular UHPC 

connection project: 

• BCV ®.

• BSI®.

• Cor-Tuf®.

• CRC®.

• Densit®.

• Ductal®.

Performance-Based Material Specification 

Method

Performance-based specifications identify the 

testing to be performed, performance levels, 

and sometimes a set of mixture proportions 

that a UHPC product must meet. This method 

of procurement creates an open but more 

involved specification. Among many items, 

the specifying agency must determine all the 

necessary performance criteria, testing methods, and acceptance criteria. In addition, the 

agency must be confident that the appropriate 

UHPC constituents and time needed to perform 

the test will be available so as not to affect the 

overall schedule of the project. Some agencies 

self-perform or hire independent material testing firms to perform parts or all of the material 

testing required. 

Using the performance-based method of procurement may be necessary for initial use of 

UHPC if no products appear on the jurisdiction’s 

pre-approved materials list. 

Specifying a set of mixture proportions is typically not recommended for UHPC because 

proposal of proprietary products is likely, and 

the constituent details of those mixes may not 

be known to the proposing entity. However, 

these criteria may sometimes be necessary, 

at least within defined proportion ranges, to 

prevent inappropriate products from being 

proposed to the agency.
18

Examples of mixture requirements that could 

be included in a UHPC specification include the 

following:

• Water-to-cementitious materials ratio < 0.25.

• Portland cement content ≥ 1,000 lb/yd3

(593 kg/m3

).

• Maximum aggregate size ≤ 0.25 times the 

fiber length.

• Maximum aggregate size ≤ 0.125 inches 

(3.2 mm).

• Steel fiber reinforcement geometry, 

strength, and volume percent.

Material Performance Testing: Laboratory 

and Field

Identification of material performance tests and 

acceptance criteria is highly recommended. 

They provide a means to assess the properties of a particular UHPC mix design and 

can validate the appropriateness of material 

characteristics to the intended needs of a 

project. Some material performance tests 

are appropriate for completion in the 

laboratory before the construction of a project, 

but other tests are performed during 

construction. 

Many of the UHPC tests conducted are wellestablished tests used for conventional 

concrete. For some tests, the procedures may 

need to be modified to capture the true behavior of UHPC and to expedite testing. Table 2 

describes commonly recommended materials 

tests, test frequency, acceptance criteria, and 

the stage of project delivery when they should 

be conducted. 

The manufacturer of the steel fiber reinforcement should provide documentation 

indicating the chemical composition, 

the tensile mechanical properties, and the 

geometry of the fibers. Samples may be 

retained during construction for future analysis 

if there are any questions about the properties 

of the fibers. 

Test Method ASTM Material 

Vetting QA/QC QA/QC 

Frequency Acceptance Criteria

Flow C1437 Yes Yes Once per mix

• Flow diameter before and after 

drops—project specific

• Flow range from 7 to 10 inches 

(178 to 254 mm).

Compressive 

strength

C39

C109 Yes Yes

At least

once per 

25 yd3

(19 m3

) or 

once per 

12-h shift

• > 14 ksi (97 MPa) after 4 days

• > 21 ksi (145 MPa) after 28 days

• > 14 ksi (97 MPa) before application 

of construction or live loads

Chloride ion 

penetrability C1202 Yes Not 

Common N/A • ≤ 250 coulombs by 28 days

Freeze-thaw 

resistance C666A Yes Not 

Common N/A • RDM ≥ 95 percent after 300 cycles

Shrinkage C157 Yes Not 

Common N/A

• ≤ 800 microstrain at 28 days

• Consider curing scenarios

Table 2. Material tests commonly applied to UHPC used in field-cast connections.

N/A = not applicable

QA/QC = quality assurance/quality control

RDM = relative dynamic modulus of elasticity
19

Flow Tests

Rheological properties describe the flow characteristics of a given UHPC mix design. It is 

important to quantify these properties because 

an overly stiff mix may not allow the UHPC to 

flow into the connections, but an overly fluid 

mix can result in the segregation of the steel 

fiber reinforcement to the bottom of the pour. 

A slightly modified version of ASTM C1437 (see 

figure 10) is used to determine the appropriate 

rheological properties for UHPC.(21)

The test is a miniaturized version of the 

spread test used for self-consolidating 

concrete. The C1437 test requires the dynamic 

spread of the mix to be measured only after 

the 25 table drops. As commonly implemented 

with UHPC, the test also includes a measurement of the initial spread of the UHPC before 

the initiation of the table drops. At the conclusion of this test, the UHPC can also be assessed 

for fiber distribution and matrix segregation.

Flow tests conducted in the laboratory establish the acceptable initial and dynamic spreads 

for a given project application and can be used 

to determine the sensitivity of the mix to constituent and environmental variations. These 

laboratory tests can also help establish acceptable ranges of constituent variations if they are 

needed during construction. 

During construction, flow tests are conducted 

immediately after mixing to assess the mix 

before placement. Testing may also occur 

during placement operations to address 

environmental changes that may influence the 

mix and to assure consistency among batches. 

The degree of variation in flow should be 

within the prescribed ranges established from 

previously conducted laboratory tests. 

Adjustments to mix constituents or mixing 

processes to address environmental conditions may be necessary; however, any changes 

should be consistent with guidance provided 

by the material supplier and/or developed 

during preliminary testing. Variations in constituents may include minor modifications to 

the amount of water and/or superplasticizers.

Compression Tests

Similar to conventional concrete, compressive 

strength testing is performed on UHPC to indi

cate the compressive response of the material. 

Research has demonstrated that standard con

crete compression testing methods (i.e., cylinders in ASTM C39 and cubes in ASTM C109) are 

applicable to UHPC.(22,23) However, these tests 

may benefit from a slight modification. Because 

of the high strength of UHPC, an accelerated 

loading rate of 150 psi/s (1 MPa/s) has been demonstrated to allow expedited testing without 

adversely affecting the observed response.(24)

It has also been demonstrated that full-size 

cylinders can be substituted with reduced-size 

cylinder or cube compressive test specimens. 

Based on a series of companion cylinder and 

cube strength compression tests completed 

over a range of nominal strengths, the observed 

values fell within 5 percent of one another, 

allowing for direct substitution of results.(25) The 

reduced-size specimens save on material use, 

reduce waste, simplify the handling and transport of specimens, and allow the use of smallercapacity compression testing equipment. 

If compression tests are used on specimens at 

strength levels above those appropriate for end 

capping, both cylinder ends must be ground 

to within the ASTM C39 specification of 0.5 

degrees.(22) It is also important to recognize that 

the high compressive strengths of UHPC may 

necessitate the use of higher-capacity compression testing platens and machines.

Both 3- (76-) and 4-inch (102-mm)-diameter 

cylinders are frequently used to determine the 

compression strength of UHPC. Typically, at 

Figure 10. ASTM C1437 flow test on UHPC.
20

least three cylinders are tested for each test 

condition to determine an average indication of 

strength. If laboratory testing is used to determine the curing behaviors of field-cast connections, then the cylinders should be match-cured 

in a manner that is similar to the anticipated 

in-field conditions.

Construction Specifications for UHPC

In-field activities related to the storage, mixing, 

and placement of the UHPC are often detailed 

in the construction portion of the UHPC specification. Some specifications require contractors to demonstrate competence with the 

mixing and placement of UHPC materials 

before the start of actual work. Construction 

specifications may include trial mixing; 

specification of the order and manner of 

constituent mixing, mixing equipment, 

placement, testing, adequacy of formwork, 

and bond surface preparation; and demonstration of appropriate staffing and equipment. 

For proprietary UHPCs, specifications typically 

require that a supplier representative be onsite 

during UHPC mixing and placing operations. 

These construction specifications may also 

prescribe curing methods, onsite material 

storage, and material usage time frames (i.e., 

expiration dates).

In locations where UHPC connections have 

been deployed, the construction community 

has generally developed the necessary skill set 

through a willingness to modify their normal 

construction processes according to past experience and expert advice. The following information is provided as an introduction to some 

of the common aspects related to the construction of field-cast UHPC connections. Material 

testing that occurs in the field was discussed in 

the previous section.

Surface Preparation for Bond

The preparation of surfaces where the precast 

component bonds with the field-cast UHPC is 

critical to ensure durability and long-term performance of the system. Lack of bond allows 

water infiltration and potentially accelerates the 

degradation of the concrete and embedded rebar. 

UHPC can bond exceptionally well to conventional concrete at connection interfaces; however, the bond strength is highly dependent on 

the surface preparation of the precast concrete. 

Similar to other cementitious materials, UHPC 

is not likely to form a strong bond with smooth, 

dry, precast concrete. A better bond is achieved 

with a surface exhibiting micro- and macrotexture. Good bonding has been demonstrated 

when UHPC is cast against a precast concrete 

element with an exposed aggregate finish. An 

exposed aggregate finish can be created by 

applying a gelatinous retarder to the formwork 

in locations where the finish is desired. The 

hydration reaction of the fresh concrete contacting the retarder is delayed. After form removal, 

the unhydrated paste can be washed from 

hardened concrete with water. This process 

is similar to that sometimes used to create an 

architectural finish on a precast panel; however, 

here it is used to create a structural bonding 

surface. An example of this type of surface 

finish is shown in figure 11, along with a 

sandblasted surface finish and a steel-form 

surface finish. Other examples of the exposed 

aggregate surface finish are provided later in 

this document.

Pre-wetting the precast concrete interface to an 

SSD condition immediately before the UHPC is 

placed also improves bonding because it eliminates the dehydrating effect that occurs when 

dry concrete extracts water from the newly 

placed UHPC. 

It is preferable to obtain a well-bonded interface 

through the normal UHPC connection construction process than to implement remedial 

solutions to seal unbonded areas. For this 

reason, it is helpful to encourage the use of 

construction processes that are likely to result 

in fully bonded interfaces. 

Specifications to promote a good bond might 

include language speaking to the following 

qualities: 

• A roughened surface on the precast concrete component with current best practice 

providing an exposed aggregate finish.

• The wetting of a precast surface to an 

SSD condition immediately before UHPC 

placement. 
21

Owners may consider including a section in 

their UHPC specification to address the following issues: 

• Construction activities that promote good 

bonding such as those mentioned above. 

• Methods to assess bond performance such 

as completing a water-tightness test on a 

bridge deck. 

• Remedial solutions if the bond is found 

insufficient, such as specifying a sealing 

procedure for any identified unbonded 

areas. 

Formwork

Fresh UHPC is a fluid, self-consolidating material that contains little or no coarse aggregate. 

Because of these features, the formwork used 

to contain the material requires tighter control 

than the formwork used for conventional 

concrete. UHPC also places higher pressures against the formwork compared with 

conventional concretes. Formwork that will be 

in contact with the UHPC should have a nonabsorbing finish.

Success or failure of UHPC placement is directly 

related to contractor and construction inspector 

attentiveness to ensuring that the formwork is 

properly sealed and capable of resisting 

the hydrostatic pressures from the UHPC 

in the unhardened state. Some contractors 

have gone so far as to temporarily fill connection forms with water to ensure leak tightness 

and to validate pressure resistance. Although 

not necessary, this activity can prove beneficial 

as a learning tool. 

As is common with fluid materials cast into 

enclosed spaces, trapped air must be provided 

an exit so that the space can be filled by the 

UHPC.

Small amounts of air trapped in the UHPC and 

in the connection spaces during placement can 

result in the UHPC initially appearing to fill the 

void space, and then later subsiding slightly 

as the air escapes. To address the subsidence, 

forms are constructed to allow a slight overfilling of the connection and may include features 

to provide a slight pressure head on the pour 

after it is placed. 

An example of these details can be seen with 

precast deck panel connections that use UHPC. 

Wood strips are frequently installed on either 

side of the top of the connection to allow 

overfilling. As is done with grout, UHPC is 

placed starting from the low end of the pour. 

The formwork is capped at the low end to prevent the material from escaping as subsequent 

material is placed into the joint. In nearly all 

cases, the formwork has a “chimney” to address 

any subsidence effects from the release of air 

as described earlier. The chimney also sustains a slight pressure head on the unhardened 

Figure 11. Exposed aggregate surface finish on a precast concrete component.
22

UHPC material to ensure that the connection 

space remains completely filled. Figure 12 

shows the filling of a bucket that serves as the 

overpressure source for a connection space 

that has been filled. The bucket is attached to 

the top form, and both contain a hole allowing the UHPC to flow into the connection as 

needed.

It can be advantageous to include formwork 

features on the prefabricated components to 

lessen the demand for field-installed formwork. 

For example, detailing deck panels or decked 

girders to include extended concrete “lips” at 

the bottom of the deck-level connection can 

eliminate the need for under-connection formwork and can simplify field construction activities by allowing for top-down construction.

Mixing

As with any pre-bagged cementitious composite, UHPC must be mixed according to the 

specifications. For UHPC, these specifications 

commonly provide information on the constituent volumes and the order and timing needed 

to mix the material. UHPC is sensitive to mixing 

deviations, so the timing and mix proportions 

must be followed. The addition of water or 

chemical admixtures above or below previously established ranges can be detrimental 

to the early and long-term performance of the 

material.

Weather conditions can also affect the properties of the UHPC before and during the 

mixing operations. The temperature of the 

UHPC increases during mixing, and some mix 

water is lost because of evaporation. Best 

practices call for the mixing operations to 

occur under cool temperatures and away from 

direct exposure to sun and wind. Maintaining a 

reduced temperature of 50 to 60 °F (10 to 16 °C) 

on stockpiled materials and mix water is also 

advantageous on warm days. The fluidity of 

UHPC can become reduced, and the likelihood 

of surface dehydration can increase, if the 

temperature of UHPC at the conclusion of mixing exceeds 80 °F (26.7 °C). Cubed ice has been 

demonstrated to be a viable replacement for 

some or all of the mix water when mixing operations occur during warm weather conditions.

UHPC can be mixed in most concrete or grout 

mixers. UHPC requires mixers to properly disperse the liquids uniformly within the powder 

matrix, with higher-efficiency mixers more 

effectively completing this task. Both towbehind pan mixers and conventional concrete 

ready-mix trucks have been used to mix UHPC; 

however, higher shear mixers can be desirable 

because they can significantly increase the 

efficiency of the mixing process. As a rule of 

thumb, the maximum volume of UHPC that 

can be mixed in any of these mixers is approximately half of the volume of conventional 

concrete or grout that could be mixed.

The mixer type selection and the number of 

mixers should be determined based on the 

rate of UHPC delivery required for the project. 

Figure 13 shows a portable concrete pan mixer 

preparing UHPC that was used in the field-cast 

connections for the Keg Creek Bridge in Council 

Bluffs, IA.

Field-cast connections on short- to mediumspan bridge projects may require 10 yd3

 (7.6 m3) 

Figure 12. UHPC placement into a bucket that serves 

as the overpressure source for a connection.
23

or more of UHPC. Commonly deployed mixers can only mix a fraction of this volume per 

batch. Most UHPC connections details need to 

be divided into smaller sections so the mixing 

and placement rates allow the UHPC connection to be filled uniformly. Like conventional 

concrete or grouts, this requirement is needed 

to control the locations of any cold joints within 

the mass of field-cast concrete. 

Placing

Traditionally, the conveyance of UHPC from 

the mixer into the field-cast connection has 

been through motorized or non-motorized 

wheelbarrows. Individual connections are 

filled consecutively. It is possible to pump, 

augur, or chute UHPC; however, these methods should be demonstrated in advance and be 

carefully coordinated to ensure appropriate 

delivery of the material to the connections. 

Figure 14 shows UHPC placement on a bridge 

in Lyons, NY. 

Figure 13. Portable concrete pan mixer preparing 

UHPC for placement during the construction of the 

field-cast connections.

Figure 14. Longitudinal connections cast between deck-bulb-tee girders on the Route 31 bridge in Lyons, NY.

© New York State Department of Transportation
24

Because deck-level UHPC connections are 

fully exposed to the weather during casting, the leading exposed surface of the 

pour can desiccate and crack before the 

void space is completely filled and the 

connection is covered. Often, these deck-level 

connections are subdivided in a manner that 

is determined by the speed with which 

the mixing and placement can occur. 

Methods to estimate conventional concrete 

surface dehydration rates are available 

and can be used by the UHPC supplier, 

contractor, and construction inspection personnel to tailor the placement process.(26)

When two “heads” of adjacent UHPC pours 

meet one another, an interface is formed, 

and there is limited interface crossing by 

the fiber reinforcement. This situation can 

be avoided by prescribing that all succeeding UHPC placements should be poured into 

previously placed, fluid UHPC. 

It is rare for UHPC to require vibration to fill the 

area being cast. UHPC should not be internally 

vibrated because of the detrimental impact that 

this type of vibration has on the fiber reinforcement (i.e., it may settle to the bottom of the 

pour). External vibration is commonly impractical because of site conditions. Rodding is 

acceptable and is sometimes used in situations 

where two successive pours meet.

Finishing

Traditional concrete finishing practices are not 

used on field-cast UHPC. The low waterto-cement ratio and high supplementary 

cementitious content virtually eliminates 

bleed water from the surface of the concrete. 

Because of these limitations, alternate techniques must be used to ensure an appropriate 

concrete surface. UHPC is typically placed in 

a closed form, or the form is closed immediately after placement. The closed form should 

be designed to allow full filling of the connection 

space without trapping air. On flat surfaces 

exposed to air, UHPC should be in contact 

with the top formwork to minimize surface 

dehydration. For horizontal surfaces that are 

visible to the public, the connection is frequently 

overfilled (see Formwork section). This process 

allows the UHPC surface to be ground 

to match the adjacent prefabricated surfaces.

Curing and Strength Gain

To reduce the risk of surface dehydration, UHPC 

should remain sealed from exposure to the 

external environment until after initial set has 

occurred. UHPC may be, but does not need to 

be, moist cured because of the low permeability 

of the cementitious matrix. Also, UHPC should 

not freeze before attaining 10 ksi (70 MPa) of 

compressive strength.

UHPC-class materials can exhibit long dwell 

times before the start of initial set. After initial 

set has occurred, strength quickly develops. 

The timing of initial set is dependent on the 

temperature of the UHPC at time of placement, 

the temperature conditions surrounding the 

material, the admixtures included, and the 

cement type used. Although cooler temperatures are beneficial for mixing and placing 

UHPC, warmer temperatures are beneficial to 

initiate the initial set. 

Supplemental heat can be provided to the UHPC 

and the surrounding prefabricated elements to 

reduce initial set times and accelerate strength 

gain. This heat can be supplied externally (e.g., 

ground heating mats) or internally (e.g., resistance heating wires). To prevent the extraction 

of moisture from the mix, heat sources that use 

forced air should not be applied to exposed surfaces of freshly poured UHPC.

As with any field-cast grout, construction 

activities that induce relative movement into 

connections before the grout is set can weaken 

the connection. These relative movements can 

reduce the capacity of embedded connectors 

by decreasing the bond with grout. This topic 

is of particular relevance in the staged construction connections that are sometimes used 

during bridge deck rehabilitations. Ideally, relative movements should be minimized until the 

UHPC has set and attained 14 ksi (97 MPa) of 

compressive strength.

Formwork may be stripped after a compressive strength of 14 ksi (97 MPa) is reached. 

Cementitious reactions continue to occur as the 

full mechanical and durability properties are 
25

Figure 16. Surface profiling of a bridge deck on I-81 

near Syracuse, NY.

Figure 15. Surface profiling of a bridge deck on I-690 

near Syracuse, NY.

© Lafarge North America © Lafarge North America

achieved; however, the UHPC may be exposed 

to the environment without experiencing any 

deleterious effects. The structure may be 

subjected to construction and/or traffic live loads 

after 14 ksi (97 MPa) is reached; however, care 

must be taken not to overstress the connections 

before attainment of the design strength.

Surface Profiling

Horizontal field-cast UHPC surfaces, such as 

the exposed surfaces of precast deck panel 

connections, must be profiled for rideability. 

Frequently, the top face of the precast concrete 

deck component is designed with a sacrificial 

surface that can also be profiled after installation and connection casting. 

Grinding/grooving operations of field-cast 

UHPC connections (and surrounding precast 

component decks) have been successfully completed on prefabricated bridge decking projects. 

Some contractors have reported that grinding/

grooving is easier if completed before the UHPC 

reaches its full compressive strength. The ease 

with which these operations can be completed 

depends on the UHPC strength, the UHPC formulation, and the type of grinding/grooving 

equipment deployed. Figure 15 and figure 16 

shows two methods of surface profiling of 

bridge decks on interstate highways.

Construction Engineer Inspection

The monitoring of construction activities is 

a critical part of the deployment of field-cast 

UHPC connections. As with any phase of a 

bridge construction project, this phase requires 

close attention to process and the generation of 

appropriate documentation. The construction 

engineering inspector must be familiar with the 

overall construction process as well as specific 

differences associated with the deployment of 

this technology compared with conventional 

grouts and concretes. Some examples of specific items to consider are as follows: 

• Familiarity with specification for UHPC and 

any other relevant special provisions. The 

inspector must understand the documentation associated with the project and must 

use it as the framework through which the 

field construction activities are completed.

• Worker safety equipment and procedures. 

The inspector must be familiar with safety 

precautions relevant to the deployment of 

UHPC in this type of construction project. 

In particular, the powdered constituents of 

UHPC are exceptionally fine and can become 

airborne more easily than traditional portland cement. Also, the steel fiber reinforcement commonly has a very small diameter 

and, if handled incorrectly, can lead to punctures of clothing, safety equipment, and skin.

• Prior coordination of construction activities. Construction projects of this type 

commonly include coordination activities 

before the initiation of the construction 

process. These coordination activities may 
26

include practice batching, mixing, and placing of the UHPC either on or adjacent to the 

site by the construction crew that will thereafter be completing the UHPC connections. 

Testing all relevant equipment immediately 

before the start of construction activities is 

also important.

• Lot numbers, dates, and storage of constituent materials. The inspector must 

ensure that the constituents are tracked 

before use and are recorded in concert with 

the use of the constituents. Also, the constituents must be stored appropriately to 

avoid degrading the products before use. 

This step is particularly important to avoid 

any unintentional hydration of the UHPC 

cementitious composite before the initiation of mixing.

• Mixing process, including weighing, timing, 

and discharge. The inspector must ensure 

that the proper constituents are added to 

the mixer within the predetermined proportion ranges and timeframes. The mixing operation should be timed because the 

mix time across batches provides an indication of the consistency of the product being 

delivered. The temperature at discharge 

is also an indicator of consistency and, if 

too high, can be an indicator of likely future 

placement difficulties.

• Formwork considerations. Forms for 

field-cast UHPC must be tighter than normal because of the rheology of UHPC. 

Formwork leakage and the resulting common remedies are less effective because 

of the rheology of UHPC. Long connections 

are commonly divided into smaller length 

spaces in order to allow for rapid filling and 

closure of individual connections.

• Surface preparation. The precast concrete 

surfaces against which the UHPC will be cast 

must be appropriately prepared to achieve 

appropriate bond performance. The inspector should ensure that the interface surfaces meet the construction requirements 

for roughness and that they are free of foreign materials. Prewetting of these surfaces 

to an SSD condition immediately before 

UHPC placement is commonly specified 

and must be monitored by the inspector.

• Pour locations and volumes per pour location. The inspector must ensure that the 

construction process follows the recommended practice regarding UHPC volumes 

per connection location. Overly large connections result in difficulty bringing any one 

connection space to a fully filled condition. 

The inspector must be aware of pour 

locations, connection geometry, and pour 

volumes to ensure that the UHPC connections 

are being filled in an appropriate, sequential, 

and timely fashion.

• Placement of UHPC. The UHPC should be 

placed into each connection space without 

the use of vibration. Vibration can cause 

disruption in the dispersion of the steel 

fiber reinforcement. If placed through discontinuous pours, successive additions of 

UHPC should be poured into fresh, previously placed UHPC. UHPC can be rodded at 

locations where successive pours meet. 

• Form closure requirements, including overpressure. The inspector must monitor the 

process as each connection space is filled 

and any top forms are installed. UHPC can 

subside because of either continued flow 

into unfilled areas or release of entrapped 

air. Full filling plus overpressure from a 

chimney is commonly recommended and 

thus must be monitored.

• Curing requirements. The inspector must 

ensure that the field-cast UHPC is cured 

appropriately to develop material properties in a reasonable timeframe.

• Surface preparation of hardened UHPC. 

Uppermost UHPC surfaces within a connection space, such as the connection surface 

on a bridge deck, commonly require dressing to create an appropriate surface profile. 

This step may include grinding and grooving. These operations are easier to complete 

after the UHPC has hardened and before it 

has gained its full strength. Early dressing 
27

Figure 17. Superstructure prepared for precast panel installation.

can result in tearing of the UHPC, and late 

dressing can unnecessarily cause wear to 

the dressing equipment. Inspectors should 

monitor the timing of these operations.

• Field test methods for assessing fresh 

properties. The inspector must be familiar 

with the test methods used to assess the 

fresh properties of the UHPC. The inspector 

must ensure that the tests are completed 

correctly and at appropriate times and that 

the test results are recorded.

Case Study: Construction of I-81 

Bridges in Syracuse, NY

NYSDOT is a leader in the deployment of 

innovative solutions that use of field-cast 

UHPC connections. After constructing dozens 

of bridges using UHPC, the design and construction community is growing more familiar 

with this material and is finding new ways to 

use it. This familiarity has led to many successful projects and new ideas that improve design, 

fabrication, and construction efforts needed for 

bridge construction. This section describes a 

case study on four interstate bridges that were 

recently constructed near Syracuse, NY, that use 

UHPC details, precast full depth deck panels, 

no post-tensioning, and no panel leveling screws.

Four bridges on I-81 were rapidly re-decked 

using precast concrete deck panels and fieldcast UHPC connections. One pair of bridges 

spanned East Castle Street, and the other pair 

spanned East Brighton Avenue. NYSDOT chose 

to reconstruct the decks of the two bridges 

on the southbound alignment using a 10-day 

closure and then repeat the same accelerated 

process for the northbound structures. 

All four bridges have steel superstructures that 

were being retained while their decks, parapets, 

and approach slabs were replaced. Figure 17 

shows one of the bridges after the demolition 

of the existing deck and before the installation 

of the new precast deck panels. The steel shear 

studs are installed along with the cold-formed 

steel angles that will serve as the haunch formwork.

The next phase of the deck reconstruction is 

the installation of the precast deck panels and 

precast approach slabs. Figure 18 shows one 

of the deck panels being lifted from the truck. 

This panel spans transversely across the bridge 

between the interior girders of the bridge. 
28

Figure 18. Transport and rigging of precast deck panel.

Figure 19. Installation of precast panel with integral barrier.

Figure 19 shows the installation of a deck panel 

that spans over the exterior girder and first interior girder. The panels from figure 18 can be seen 

just to the left of the first interior girder line.

Note that the barrier has been cast integral to 

the panel shown in figure 19. These exterior 

panels were fabricated upside down. This 

method of fabrication offers benefits to the 

owner and the contractor (e.g., the top of the 

deck and the parapet are composed of high 

quality, well-consolidated concrete).
29

The connection details used in this reconstruction project use the field-cast UHPC connection concepts presented earlier in this document. The connection details between the 

precast panels use a noncontact lap splicing of 

straight lengths of epoxy-coated reinforcement 

embedded in UHPC. This detail is shown in

figure 20. Note that exposed aggregate surface 

was used to increase the bond at the mating 

surfaces. 

The deck-to-girder connections above the first 

interior girder also use a field-cast UHPC connection detail, shown in figure 21. The detail 

at this location combined the deck-level connection with the deck-to-girder connection in 

a unique way that facilitated construction and 

maximized the value of the UHPC.

A hidden pocket composite connection 

detail was used above the other girder lines 

on these bridges. Although this detail was 

forced to use conventional grout because 

of now-superseded Buy America provisionrelated constraints, the connection details 

do demonstrate a concept worthy of note. 

Figure 22 shows the bottom mat of reinforcement in the deck panel and the exposed 

aggregate surface that is used to improve 

the interface bond. Because this detail uses 

conventional grout, the shear stud heads are 

required to extend above the bottom mat of 

reinforcement, as shown in figure 23. As discussed earlier in this document, the embedment of the shear studs above the bottom mat 

would not need to occur if UHPC was used 

in the connection. This detail can be seen in 

figure 6 and in figure 21. 

The mixing, transport, and placement of the 

UHPC into the connections for each bridge deck 

was completed over the course of a few hours, 

as shown in figure 25 and figure 26. The UHPC 

was mixed adjacent to the bridge site in a pair 

of mixers that alternately discharged approximately 0.65 yd3

 (0.5 m3) of UHPC. Motorized 

buggies transported the UHPC to the connections. The UHPC was then poured into the 

connections until the local area was filled. 

The filled connection was then covered with 

plastic and a plywood lid to facilitate appropriate curing of the cementitious composite.

After the UHPC had developed sufficient 

strength, the formwork was removed, and the 

entire surface of the bridge deck was ground and 

Figure 20. Deck-level connection between precast deck panels.
30

Figure 22. Connection detail on underside of precast 

deck panel.

Figure 23. Hidden pocked connection detail with 

shear studs extending above the bottom mat 

of rebar to allow use with non-UHPC grouts or 

concretes.

grooved. This operation allowed the creation 

of a consistent, uniform driving surface over 

the entirety of the bridge deck, approach slabs, 

and approach pavement. The grinding included 

removal of concrete from both the UHPC 

connections and the precast deck panels, 

which also included sacrificial concrete. 

Figure 27 shows a completed bridge deck with 

two of the lanes open to traffic.

Figure 21. Longitudinal connection detail above first interior girder line with shear studs stopping below the 

bottom mat of rebar.
31

Figure 24. Bridge deck after panel installation and before UHPC placement.

Figure 25. Mixing operation for the field-cast UHPC.
32

Figure 26. Placing operation for the field-cast UHPC.

Figure 27. Bridge deck after grinding, grooving, and opening to traffic.

Deployments

Over the past few years, dozens of highway 

bridge projects using field-cast UHPC connections between prefabricated elements 

have been completed in the United States.

Table 3 lists the projects that have been completed through mid-2014. Additional projects are 

under construction.
33

Route Crossing Feature Location Year Owner UHPC 

Connection

SR 31 Canandaigua Outlet Lyons, NY 2009 NYSDOT DBT

SR 23 Otego Creek Oneonta, NY 2009 NYSDOT DP

Dahlonega Road Little Cedar Creek Ottumwa, IA 2011 Iowa DOT DP, CC

Fingerboard Road Staten Island Expressway Staten Island, NY 2011–12 NYSDOT DBT

SR 248 Bennett Creek Greenwood, NY 2011 NYSDOT DBT

U.S. Route 30 Burnt River and Union 

Pacific Railroad Huntington, OR 2011 ODOT DP, CC

U.S. Route 6 Keg Creek Council Bluffs, IA 2011 Iowa DOT DG

Seven Lakes Drive Ramapo River Sloatsburg, NY 2011 NYSDOT DP

SR 42 (2 bridges) West Kill Lexington, NY 2012 NYSDOT DP, CC

SR 31 Putnam Brook Weedsport, NY 2012 NYSDOT DP

I-690 (2 bridges) Peat Street Syracuse, NY 2012 NYSDOT DP

I-690 (2 bridges) Crouse Avenue Syracuse, NY 2012 NYSDOT DP

U.S. Route 87 BNSF Railroad Moccasin, MT 2012 MDT DP, CC

I-481 Kirkville Road Syracuse, NY 2012 NYSDOT DP

SR 12 Spring Brook Greene, NY 2013 NYSDOT DP

SR 10 Webster Brook Dehli, NY 2013 NYSDOT DP

SR 38 Wilson Creek Newark, NY 2013 NYSDOT DP

SR 962G US Route 17 Owego, NY 2013 NYSDOT DP

SR 907W US Route 1 Pelham, NY 2013 NYSDOT DP

SR 2 (2 bridges) SR 9 Colonie, NY 2013 NYSDOT DG

I-81 (2 bridges) E Castle Street Syracuse, NY 2013 NYSDOT DP, CC

I-81 (2 bridges) E Calthrop Avenue Syracuse, NY 2013 NYSDOT DP, CC

I-84 (2 bridges) Dingle Road Southeast, NY 2013 NYSDOT NB

I-690 Westbound Onandaga Creek Syracuse, NY 2013 NYSDOT DP, CC

I-690 N. Salina Street Syracuse, NY 2013 NYSDOT DP, CC

SR 1004 Cove Creek Everett, PA 2013 PennDOT DP, CC

Northampton Street Manhan River Easthampton, MA 2013 MassDOT DBT

Sollars Road Lees Creek Washington Court 

House, OH 2014

Fayette 

County, 

OH

AB

SR 0288 Wampum Run Wampum, PA 2014 PennDOT DG

I-81 (2 bridges) Preble Road Preble, NY 2014 NYSDOT DG

Iowa DOT = Iowa Department of Transportation

MDT = Montana Department of Transportation

ODOT = Oregon Department of Transportation

PennDOT = Pennsylvania Department of Transportation

MassDOT = Massachusetts Department of Transportation

CC = composite connections between full-depth deck panels 

and supporting girders

DBT = deck-level connections between the top flanges of 

deck-bulb-tee girders

DG = deck-level connections between predecked modular 

steel superstructure units

DP = deck-level connections between full-depth precast 

concrete deck panels

NB = deck-level connections between NEXT beams

Table 3. Deployments of field-cast UHPC connections in the U.S. highway infrastructure.
34

Conclusion

Field-cast UHPC connections provide new 

opportunities to create robust structural systems composed of prefabricated components. 

Research has demonstrated the performance 

of these connection concepts in the laboratory. Initial deployments in the highway bridge 

inventory have demonstrated the constructability and field performance of these systems. This document provides design and 

construction guidance relevant to field-cast 

UHPC connections. It is expected to facilitate 

broader deployment of prefabricated bridge 

elements by providing owners and contractors 

with the tools necessary to specify, design, and 

construct a new class of robust connection 

details. 

Notation

db = nominal bar diameter 

Ec = modulus of elasticity of concrete 

fc ́ = concrete compressive strength 

ft,crack = cracking tensile strength of concrete 

fy = yield strength of reinforcing bars 

ld = embedment length 

ls = lap splice length 

References

1. Russell, H., and Graybeal, B., Ultra-High 

Performance Concrete: A State-of-the Art 

Report for the Bridge Community, FHWAHRT-13-060, McLean, VA, June 2013.

2. Graybeal, B., Ultra-High Performance 

Concrete, FHWA-HRT-11-038, McLean, VA, 

March 2011.

3. Graybeal, B., Construction of FieldCast Ultra-High Performance Concrete 

Connections, FHWA-HRT-12-038, McLean, 

VA, April 2012.

4. Wille, K., Development of Non-Proprietary 

Ultra-High Performance Concrete for Use 

in the Highway Bridge Sector, Report No. 

PB2013-110587, NTIS, Springfield, VA, 

October 2013. 

5. ASTM Standard C150 (2012), Standard 

Specification for Portland Cement, ASTM 

Book of Standards, Volume 04.01, West 

Conshohocken, PA. 

6. API Specification 10A (2010), Specification 

for Cements and Materials for Well 

Cementing, American Petroleum Institute.

7. U.S. Department of Transportation, Federal 

Highway Administration, Ultra High 

Performance Concrete (UHPC)—Availability 

of Domestic Source of Steel Fiber 

Reinforcement and Proprietary Product 

Concerns, Memorandum, February 2014.

8. Graybeal, B., Material Property 

Characterization of Ultra-High Performance 

Concrete, FHWA-HRT-06-103, McLean, VA, 

August 2006.

9. Graybeal, B., and Stone, B., Compression 

Response of a Rapid-Strengthening UltraHigh Performance Concrete Formulation,

FHWA, NTIS, Accession No. PB2012-112545, 

September 2012.

10. Graybeal, B., and Baby, F., “Development 

of a Direct Tension Test Method for UltraHigh-Performance Fiber-Reinforced 

Concrete,” ACI Materials Journal, 110(2), 

March 2013, pp. 177–186.

11. Swenty, M., and Graybeal, B., Material 

Characterization of Field-Cast Connection 

Grouts, FHWA, NTIS, Accession No. PB2013-

130231, January 2013.

12. AASHTO Highway Subcommittee on 

Bridges and Structures, AASHTO LRFD 

Bridge Design Specifications, AASHTO, 

Washington, DC, 2013.

13. Graybeal, B., Behavior of Field-Cast UltraHigh Performance Concrete Bridge Deck 

Connections Under Cyclic and Static 

Structural Loading, FHWA, NTIS, Accession 

No. PB2011-101995, November 2010.

14. Yuan, J., and Graybeal B., Bond Behavior of 

Reinforcing Steel in Ultra-High Performance 

Concrete, FHWA-HRT-14-089, McLean, VA, 

2014.

15. Graybeal, B., Ultra-High Performance 

Concrete Composite Connections for 

Precast Concrete Bridge Decks, FHWA, 

NTIS, Accession No. PB2012-107569, April 

2012.
35

16. Tazarv, M., and Saiidi, S., "Emulative 

Moment-Resistant RC Bridge ColumnFooting Connection for Accelerated Bridge 

Construction in High Seismic Zone," 

Proceedings of the 7th National Seismic 

Conference on Bridges & Highways, 

Oakland, CA, 2013.

17. Bétons Fibrés à Ultra-Hautes Performances, 

Recommandations, (Ultra High 

Performance Fibre-Reinforced Concretes, 

Recommendations), AFGC, Groupe de 

travail BFUP, Paris, France, June 2013. (In 

French and English.) 

18. Thomas, M., Green, B., O’Neal, E., Perry, 

V., Hayman, S., and Hossack, A., "Marine 

Performance of UHPC at Treat Island," 

Proceedings of Hipermat 2012 3rd 

International Symposium on UHPC and 

Nanotechnology for High Performance 

Construction Materials, Ed., Schmidt, M., 

Fehling, E., Glotzbach, C., Fröhlich, S., and 

Piotrowski, S., Kassel University Press, 

Kassel, Germany, 2012, pp. 365–370.

19. Kono, K., Musha, H., Kawaguchi, T., 

Eriguchi, A., Tanaka, S., Kobayashi, T., and 

Ikeda, M., "Durability Study of the First 

PC Bridge Constructed with Ultra High 

Strength Fiber Reinforced Concrete in 

Japan," Proceedings of the RILEM-fib-AFGC 

International Symposium on Ultra-High 

Performance Fibre-Reinforced Concrete, 

Ed., Toutlemonde, F., and Resplendino, J., 

RILEM Publications, Begneux, France, 2013, 

pp. 239–248.

20. Piérard, J., Dooms, B., and Cauberg, N., 

"Durability Evaluation of Different Types of 

UHPC," Proceedings of the RILEM-fib-AFGC 

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Performance Fibre-Reinforced Concrete, 

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RILEM Publications, Begneux, France, 2013, 

pp. 275–284.

21. ASTM Standard C1437 (2007), Standard 

Test Method for Flow of Hydraulic Cement 

Mortar, ASTM Book of Standards, Volume 

04.01, West Conshohocken, PA. 

22. ASTM Standard C39 (2010), Standard 

Test Method for Compressive Strength of 

Cylindrical Concrete Specimens, ASTM 

Book of Standards, Volume 04.02, West 

Conshohocken, PA.

23. ASTM Standard C109 (2008), Standard 

Test Method for Compressive Strength 

of Hydraulic Cement Mortars (Using 2-in. 

or [50-mm] Cube Specimens), ASTM 

Book of Standards, Volume 04.01, West 

Conshohocken, PA.

24. Graybeal, B., “Compressive Behavior of 

Ultra-High Performance Fiber-Reinforced 

Concrete,” ACI Materials Journal, 104(2),

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25. Graybeal, B. and Davis, M., “Cylinder or 

Cube: Strength Testing of 80 to 200 MPa 

(11.6 to 29 ksi) Ultra-High-Performance 

Fiber-Reinforced Concrete,” ACI Materials 

Journal, 105(6), November 2008, pp. 603–

609.

26. ACI 305R-10 (2010), Guide to Hot-Weather 

Concreting, American Concrete Institute, 

Farmington Hills, MI.
36

Researchers—This document was developed by Ben Graybeal at FHWA’s Turner-Fairbank 

Highway Research Center. Additional information can be gained by contacting him at 

(202) 493-3122 or in the FHWA Office of Infrastructure Research and Development located at 

6300 Georgetown Pike, McLean, VA 22101.

Distribution—This TechNote is being distributed according to a standard distribution. Direct 

distribution is being made to the Divisions and Resource Center.

Availability—This TechNote may be obtained from the FHWA Product Distribution Center by 

e-mail to report.center@dot.gov, fax to (814) 239-2156, phone to (814) 239-1160, or online at 

http://www.fhwa.dot.gov/research.

Key Words—Ultra-high performance concrete, UHPC, fiber-reinforced concrete, bridge, 

accelerated construction, durable infrastructure system, prefabricated bridge elements and 

systems, design guidance, construction guidance, connection details.

Notice—This document is disseminated under the sponsorship of the U.S. Department of 

Transportation in the interest of information exchange. The U.S. Government assumes no 

liability for the use of the information contained in this document. The U.S. Government does 

not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this 

TechNote only because they are considered essential to the objective of the document.

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