STUDY REPORT

"SURVEY AND DESIGN OF SIMPLE SPAN PRECAST CONCRETE

GIRDERS MADE CONTINUOUS"

C. C. Fu, Ph.D., P.E. and T. Kudsi

The Bridge Engineering Software and Technology (BEST) Center

Department of Civil and Environmental Engineering

University of Maryland

September, 2000

Table of Contents

INTRODUCTION 1

SURVEY & COMMENTARY 3

Design Of Diaphragm Over Pier Of Precast Beams (Spreadsheet) 10

AASHTO –Girders Analysis, Typical (Spreadsheet Analysis) 11

Bulb-Tee Girders Analysis, Typical (Spreadsheet Analysis) 12

APPENDIX 13

STUDY REPORT

"SURVEY AND DESIGN OF SIMPLE SPAN PRECAST CONCRETE GIRDERS

MADE CONTINUOUS"

Introduction

The objective of this study for the State of Maryland is to provide a standard

detail for making simple span pre-cast concrete girders continuous for live load.

The use of prestressed pre-cast girders in bridge construction started in the United

States in the early 1950’s. Although the girders were designed as simple span for dead

load, reinforcement in the deck girders provided negative moment capacity. Recently,

the demand in the State of Maryland for making simple span precast girders continuous

over pier has increased, thus a standard detail for diaphragms over piers, showing the

necessary reinforcements for different span lengths is needed.

The study started by sending letters to the Departments of Transportation in all 50

states requesting their standard detail drawings of diaphragms over piers. Twenty-seven

states replied, sending their various approaches to continuity over piers. Although some

states did not make simple spans continuous, many states made the deck longitudinal

reinforcement resist the negative moment, and some stipulated that the diaphragm over

pier resist the negative moment due to live load. In addition to designing for negative

moment over pier, many states designed for positive moment at the supports resulting

from creep, shrinkage and elastic shortening. The latter subject will be discussed in the

section titled: ”Survey and Commentary.”

Next, a spreadsheet was prepared for all the types of AASHTO and Bulb-Tee

girders with different span lengths that were cited by the states’ replies. The spreadsheet

calculates the required reinforcement for negative moment, and positive moment for the

types of girders and span lengths that are listed. It should be noted that positive moment

in the diaphragm is usually a result of creep and shrinkage.

Many reports have discussed this issue. NCHRPR 322, ”Design of Precast Bridge

Girders Made Continuous,” concluded that positive moment connections are costly and

provide no structural benefits. On the other hand, an interim report prepared for the

National Cooperative Highway Research Program (NCHRP) Project 12-53 (1999),

“Connection between Simple Span Precast Concrete Girders Made Continuous,”

discusses the importance of accounting for positive moment resulting from creep and

shrinkage. The author of the 1999 NCHRP Project 12-53 interim report does not give a

closed form solution to standardize the calculation of the positive moment; he states that

current PCA practice does not perform a time dependent analysis, and, instead, details the

positive moment connection using 1.2Mcr.

In the spreadsheet the user is left to use the default 1.2Mcr as positive moment at

the connection, or he can input the calculated time dependent positive moment due to

shrinkage, creep, and elastic shortening.

Survey & Commentary

Letters to fifty states were sent by the BEST Center, asking them to send their

standard details for diaphragm over pier. Twenty-eight states replied to our request.

Appendix A shows a brief description for every state’s practice for continuity over pier.

The states that replied are categorized as follows:

A. States using diaphragm over pier to resist live load and superimposed dead load, and

using extended dowels or strands into the diaphragm to resist positive moments:

1. Alaska

2. Colorado

3. Delaware

4. Idaho

5. Illinois

6. Kansas

7. Michigan

8. Missouri

9. New Jersey

10. North Carolina

11. Ohio

12. Oregon

13. Pennsylvania

14. New York

B. States using diaphragm over pier without positive moment reinforcement shown:

1. Kentucky

2. Louisiana

3. North Dakota

4. Tennessee

5. Utah

6. Virginia

7. Wisconsin

8. Wyoming

9. California

C. States using deck slab to assess for continuity:

1. Georgia

2. Minnesota

D. States having no standards for continuity or not designing for continuity over pier for

live load:

1. Maine

2. Massachusetts

3. Washington

In categories A and B where the mentioned states assess for continuity over pier

by using a diaphragm, the states in category B do not show clearly the assessment for the

positive moment resulting from time dependent losses in the precast girders. Two reports

were reviewed, addressing the subject of assessing for positive moment over pier

resulting from creep, shrinkage, and elastic shortening.

In reference to Appendix G of the NCHRP report 322, “Design Of Precast

Prestressed Bridge Girders Made Continuous,” November 1989,

“Results of an analytical study (G-1) of time-dependent restraint moment and service

load moments at supports in prestressed concrete girders made continuous indicate

that there is little structural advantage gained by providing positive moment

reinforcement at supports.”

The report also states that the creep and shrinkage will produce

“A positive restraint moment at the supports that will generally induce a crack in the

bottom of the diaphragm concrete. With application of live load, the positive moment

crack must close prior to inducing negative moment at the continuity connection.

There is a loss of negative continuity moment associated with the closing of cracks in

the bottom of the diaphragm. The presence of positive moment reinforcement in the

diaphragm helps to maintain a relatively small crack, thereby increasing apparent live

load. However, the positive restraint moment resulting from the presence of the

reinforcement in the bottom of the diaphragm increases the positive moment within

the span. This increase in positive moment when bottom reinforcement is used at

supports is virtually equal to the loss of negative moment continuity if positive

reinforcement is not used. The net result on the effective continuity moment is the

same, irrespective of whether or not positive moment reinforcement is provided at

supports. Therefore, providing positive moment reinforcement has no significant

benefit for reducing service load moments.”

NCHRPR 322 proposes that the commentary should be added to section 9.7.2.2 of the

Standard Specification (AASHTO).

It should be noted that Standard Specifications for Highway Bridges, Sixteenth

Edition (1996 with Interims up to 2000) contains the statement for positive moment at

connection at piers (9.7.2.2.1),

” Provision shall be made in the design for the positive moments that may develop in

the negative moment region due to the combined effects of creep and shrinkage in the

girders and deck slab, and due to the effect of live load plus impact load in remote

spans. Shrinkage and Elastic shortening of the pier shall be considered when

significant."

In September 1999, the University of Cincinnati submitted an interim report to the

NCHRP, ”Connection Between Simple Span Precast Concrete Girders Made

Continuous.” (It is important to note that the unpublished report was obtained from

NCHRP and has not yet been released for publication.) The study team's review of the

report content is solely for the purpose of the presented study. The report concluded that

many engineers and state agencies think that positive moment connections are needed to

control cracking in the diaphragm and to provide continuity. The report also revealed

that PCA was first to identify cracking of the connection caused by time dependent

positive moments. In addition, many studies discussed in the report state that the cause

of cracking appears to be positive moment developed from time dependent deformations

of the prestressed girders.

Based on the above-presented reports, it was worthwhile to assess for positive

moment at the connection for crack control. In the submitted spreadsheet, the user is left

with the choice of assessing for positive moment reinforcement at the connection. If the

user does not wish to input any moment due to time dependent losses in the girders, the

spreadsheet will use a default entry equal to 1.2Mcr to assess for crack control in the

diaphragm.

Design and Analysis

A thorough review of standard details continuity over pier from the 28 states,

NCHRP Report 322, and NCHRP Project 12-53 Interim Report prepared by University of

Cincinnati, led to the final design of the standard detail for diaphragm over pier for the

State of Maryland. The PCI bridge design manual was also referred to for the design of

the diaphragm. The AASHTO Standard Specifications for Highway Bridges (Sixteenth

Edition) was used also. Based on the review, a spreadsheet that calculates the positive

moment reinforcement and negative moment reinforcement at a pier was constructed.

The design was based on a concrete rectangular block having a height equal to the

adjacent beams including the slab thickness, and the width was taken equal to the

adjacent beams bottom width. The spreadsheet accounts for all type of AASHTO Girders

and Bulb-Tee Girders. The user has to input the negative dead load moment combination

and live load. Also, the user shall input the positive moment due to the combined effects

of creep and shrinkage in the girder and deck slab, and to the effect of live load plus

impact in remote spans (STD. 9.7.2.2.1). If the user wishes not to input any positive

moment, the spreadsheet will use a default value equal to1.2Mcr to assess for crack

control in the diaphragm. Figure 1 shows the dimensions and reinforcement details of the

proposed diaphragm detail over pier for the State of Maryland. Referring to the

spreadsheet, Bar A is to be found for all types of girders based on the inputted dead load

and live load combinations. Bars B, C, and D are standard for all types of AASHTO and

Bulb-Tee Girders. The user can still change the latter mentioned bars.

Figure 1. Diaphragm Over Pier Detail

In Figure 2, a transverse section of the diaphragm between girders is shown. It

should be noted that horizontal reinforcements are temperature and shrinkage

requirements of ACI and AASHTO. Stirrups calculations were based on minimum

reinforcement as per ACI and AASHTO requirements. The spreadsheet includes a

detailed design and analysis for the girders types listed. A table of different types of

girder dimensions and parameters is included in the report, and a summary table of all the

states which replied is also included.

Figure 2. Transverse Cross-Section of Diaphragm

Design Of Diaphragm Over Pier Of Precast Beams (Spreadsheet)

1. Dimensions of the diaphragm over pier are shown in figure 1.

2. Layout of reinforcement is shown in figures 1 & 2.

3. Design was based on a concrete block with a width equals the girder bottom

flange width and the depth equals the beam height plus the thickness of the slab.

4. The user should enter the dead load combination and live load and impact load

combination in the assigned cells.

5. The user should choose the reinforcement to assess for negative moment over

pier, for any type of girder.

6. The spreadsheet will check the adequacy of the chosen area of reinforcement.

7. The spreadsheet calculates the required reinforcement for positive moment as per

1.2Mcr (by default). The user has the choice to enter a value for positive moment

over pier due to creep and shrinkage and remote spans. The spreadsheet will

calculate the adequacy of the inputted moment for the standard reinforcement.

8. Table 1 (Bar A): Spreadsheet user can input the chosen bar diameter and quantity

(step 1 – 10).

9. Table 2 (Bar B): the table shows the recommended standard for reinforcement for

positive moment. The user can change the standard, and the spreadsheet will

check its adequacy (step 11).

10. Table 3 (Bar C): the table shows the recommended standard for stirrups. The

user can change the standard, and the spreadsheet will check its adequacy (step

12.

11. Table 4 (Bar D): the table shows the recommended standard for temperature and

shrinkage reinforcement. The user can change the standard, and the spreadsheet

will check its adequacy (step 13).

By C. C. Fu & T. Kudsi, 8/7/00

Type I Type II Type III Type IV Type V Type VI

45 50 80 100 120 140 Diaphragm Width 30 in

36.5 44.5 53.5 62.5 71.5 80.5 fy 60000 psi16 18 22 26 28 28 f'c 7000 psi

*Depth = height of Beam + slab Thickness +Haunch - 2.5 Slab Thickness 9 inLoad Input Haunch 2 in

φ φ 0.9

0 0 0 0 0 0 ββ1 0.7

57 70 181 283 408 556 m 10.08261.87 328.5 681.5 934.34 1204.5 1485.4 fr 627.5 psi

* No sign neededNegative Moment Analysis (Bar A)

642.62 804.174 1714.84 2396.35 3145.37 3947.6 AASHTO Girders

401.96 300.81 363.10 314.60 292.98 290.08 Type I 12 # 5 13 # 5

4.05437 4.12284 7.3546 8.75837 10.0291 11.1769 Type II 12 # 5 13 # 5

7.75 7.75 7.75 11.23 11.23 11.23 Type III 12 # 5 13 # 5

1187.76 1476.23 1803.87 3048.38 3511.06 3965.88 Type IV 12 # 7 13 # 5

0.006942 0.005147 0.006249 0.005390 0.005010 0.004959 Type V 12 # 7 13 # 50.030813 0.030813 0.030813 0.030813 0.030813 0.030813 Type VI 12 # 7 13 # 5

229.078 381.203 670.918 1079.23 1518.04 1921.26 * Over the effective width* As(chosen)

- = Additional As(chosen)- + Standard Slab Reinf As

Negative Moment Checks AASHTO Girders

Type I 7 # 6OK OK OK OK OK OK Type II 7 # 6

OK OK OK OK OK OK Type III 7 # 6OK OK OK OK OK OK Type IV 7 # 7

Type V 7 # 8Positive Moment Analysis (Bar B) Type VI 7 # 8

0.00 0.00 0.00 0.00 0.00 0.00

143.29 142.59 142.06 141.68 141.40 141.18 AASHTO Girders

0.00 0.00 0.00 0.00 0.00 0.002382 Type I # 5 @ 12 in c/c closed strirrup1.4119 1.92701 2.82087 3.88407 4.7755 5.36816 Type II # 5 @ 12 in c/c closed strirrup3.08 3.08 3.08 4.2 5.53 5.53 Type III # 5 @ 12 in c/c closed strirrup

* if no value is input, spreadsheet uses a default value of 1.2Mcr Type IV # 5 @ 12 in c/c closed strirrup

Adequacy of Chosen Area Of Steel Type V # 5 @ 12 in c/c closed strirrupType VI # 5 @ 12 in c/c closed strirrup

OK OK OK OK OK OK

OK OK OK OK OK OK

AASHTO Girders

Minimum Pier Diaphragm Reinfocement between Beam (Bars C & D) Type I # 5 @ 12 in c/c /back & FrontType II # 5 @ 12 in c/c /back & Front

0.50 0.50 0.50 0.50 0.50 0.50 Type III # 5 @ 12 in c/c /back & Front

0.62 0.62 0.62 0.62 0.62 0.62 Type IV # 6 @ 12 in c/c /back & Front

OK OK OK OK OK OK Type V # 6 @ 12 in c/c /back & Front0.66 0.66 0.66 0.66 0.66 0.66 Type VI # 6 @ 12 in c/c /back & Front

0.62 0.62 0.62 0.88 0.88 0.88 **Note: Tables for Bars B,C,and D are standards, user can change the recommended NO NO NO OK OK OK reinforcement by inputting in the related cells the desired reinforcement.

The Spreadsheet wwill check the adequacy of the user's choice.

Note: Design of continuity was based on a concrete block having the width of the bottom flange and the height

of the chosen beam and chosen slab thickness

Note: Loading is Based on HS-25

Table 1: Bar A*

As(Stirrups)

Table 3 : **Bar C

As(Temperature&Shrinkage)

Table 4 :**Bar D

Standard Slab Reinf. As

As (Min), Stirrups, Bar C

As(Min, T&S), Bar D

Additional As(chosen)-

As(chosen)+

Aest+>= Achosen

+

φφMn, k-ft

*Mu+, k-ft

ρρ0.75ρρb

1.2Mcr, k-ft

AASHTO Girders

As(chosen)-, in2*

Aest->= As(chosen)

-

As(chosen)+, in2

Rn, psi

ρρAest

+, in2

φφMn > Mu

ρ ρ < 0.75ρρb

φφMn > 1.2Mcr

Rn, psi

Girder width, in

MDL-, k-ft*

MSDL-, k-ft*

MLL+I-, k-ft*

AASHTO Girder Continuity Over Pier Analysis and Design

Adequacy of Bar D

Adequacy of Bar C

Bar C, chosen in2/ft

Bar D, chosen in2/ft

Table 2 : **Bar B

Aest-, in2

Max Span Length, ft

Depth, in *

MU-, k-ft

Negative Moment Analysis

PCI-8.2.3: Design of Negative Moment Regions For Members Made Continous for Live LoadUse the width of the bottom flange as the width of the concrete compressive block, b. Determine the required

steel in the deck to resist the total factored negative Moment, assuming the compression block is uniform

Step 1 Mu = 1.3*(MDL+MSDL+1.67*MLL+I), (7.3.1-3, PCI Bridge Design Manual)

Step 2 Rn =Mu/(φbd2), (8.2.3.1-1, PCI Bridge Design Manual) ,b = width of Selected Girder

Step 3 ρ = (1/m)*(1-sqrt(1-2mRn/fy)), (8.2.3.1-2, PCI Bridge Design Manual)

Step 4 m = fy/(0.85f'c), (8.2.3.1-3, PCI Bridge Design Manual)

Step 5 As = ρbd ,b = width of Selected Girder

Step 6 φMn = φAsfy(d-a/2), (STD Eq. 8-16)

Step 7 a = Asfy/0.85f'cb, (STD Eq. 8-17) ,b = width of Selected Girder

Reinforcment Limits (Standard Specifications)

Step 8 ρb =(0.85β1f'c/fy)*(87,000/(87,000+fy)), (STD Art. 8.16.3.1)

Step 9 ρmax =0.75ρb, (STD Art. 8.16.3.1.1)

Minimum Reinforcement, (STD Art.8.17.1)

the total amount of nonprestressed reinforcement should be adequate to develop an ultimate moment at the crtical section

at least 1.2 times the cracking moment. The cracking moment may be calculated as for a prestressed

concrete section except fpe = 0

Step 10 φMn >= 1.2Mcr

Positive Moment Analysis

Step 11 Mu+ = User should input its value as per STD Art 9.7.2.2.1, if no value is inputed spreadsheet will use

a default value of 1.2Mcr

Minimum Reinforcement For Stirrups Calculations

Step 12 As (Min), Stirrups, Bar C = 0.0316*sqrt(f'c)*bw*s/fy, s = spacing = 12 in, (AASHTO LRFD-5.8.2.5-1)

where fy and f'c in step 12 are in KSI

bw = width of Diaphragm over Pier, in inches

Temperature & Shrinkage Reinforcement Calculations

Step 13 As (Min, T&S), Bar D = 0.0018*bw*h, (ACI 7.12.2.1)

bw = width of diaphragm

BT-54 BT-63 BT-72114 130 146 Diaphragm Width 30 in

62.5 71.5 80.5 fy 60000 psi26 26 26 f'c 7000 psi

*Depth = height of Beam + slab Thickness +Haunch - 2.5 Slab Thickness 9 inLoad Input Haunch 2 in

φ φ 0.9

0 0 0 ββ1 0.7

368.29 479.43 605.2 m 10.0841122.83 1317.82 1590.59 fr 627.495 psi

* No sign neededNegative Moment Analysis (Bar a)

Bulb-Tee Girders

2916.44 3484.25 4239.93 Type I 12 # 7 13 # 5382.88 349.51 335.53 Type II 12 # 7 13 # 510.7266 11.1673 12.0545 Type III 12 # 8 13 # 511.23 11.23 13.51 * Over the effective width

3048.38 3503.20 4734.72

0.006601 0.006007 0.005759 Bulb-Tee Girders

0.030813 0.030813 0.030813 Type I 6 # 5372.251 550.627 792.903 Type II 6 # 5

* As(chosen)- = Additional As(chosen)

- + Standard Slab Reinf As Type III 6 # 6

Negative Moment Checks

OK OK OK Bulb-Tee Girders

OK OK OK Type I # 5 @ 12 in c/c closed strirrupOK OK OK Type II # 5 @ 12 in c/c closed strirrup

Type III # 5 @ 12 in c/c closed strirrup

Positive Moment Analysis (Bar B)

0.00 0.00 0.00 Bulb-Tee Girders

48.87 55.23 62.75 Type I # 8 @ 12 in c/c Back & Front

0.00 0.00 0.00 Type II # 9 @ 12 in c/c Back & Front1.32904 1.71937 2.20049 Type III # 9 @ 12 in c/c Back & Front

1.86 1.86 2.64 **Note: Tables for Bars B,C,and D are standards, user can change the recommended

* if no value is input, spreadsheet uses a default value of 1.2Mcr reinforcement by inputting in the related cells the desired reinforcement.

The Spreadsheet wwill check the adequacy of the user's choice.

Adequacy of Chosen Area Of Steel

OK OK OKOK OK OK

Minimum Pier Diaphragm Reinfocement between Beam (Bars C & D)

0.50 0.50 0.50

0.62 0.62 0.62

OK OK OK0.66 0.66 0.66

7.11 10.50 12.00OK OK OK

Note: Design of continuity was based on a concrete block having the width of the bottom flange and the height

of the chosen beam and chosen slab thickness

Note: Loading is Based on HS-25

0.75ρρb

Aest->= As(chosen)

-

Aest+>= Achosen

+

As(chosen)+, in2

φφMn > Mu

ρ ρ < 0.75ρρb

φφMn > 1.2Mcr

MDL-, k-ft *

MSDL-, k-ft *

MLL+I-, k-ft *

MU-, k-ft

Bulb-Tee GirdersMax Span Length, ft

Depth, in *Girder width, in

Adequacy of Bar D

Table 2 : **Bar BAs(chosen)

+

As(chosen)-

Rn, psi

Aest+, in2

Step 11Mu+, k-ft *

As (Min), Stirrups, Bar C

As(Min, T&S), Bar D

ρρ

Bulb-tee Girder Continuity Over Pier Analysis and Design

Bar C, chosen in2

Adequacy of Bar C

Bar D, chosen in2

ρρ

Aest-, in2

As(chosen)-, in2

φφMn, k-ft

Rn, psi

1.2Mcr, k-ft

Standard Slab Reinf. AsTable 1: Bar A*

Table 4 : **Bar DAs(Temperature&Shrinkage)

Table 3 : **Bar CAs(Stirrups)

Type I Type II Type III Type IV Type V Type VIh, in 28 36 45 54 63 72 Bar # Area DiameterAc, in

2 276 369 560 789 1013 1085 3 0.110 0.375

Ig, in4 22,750 50,979 125,390 260,741 521,180 733,320 4 0.200 0.500Sections c1, in 15.41 20.17 24.73 29.27 31.04 35.62 5 0.310 0.625

c2, in 12.59 15.83 20.27 24.73 31.96 36.38 6 0.440 0.750

r2, in2 82 138 224 330 514 676 7 0.600 0.875Properties wo, plf 288 384 583 822 1055 1130 8 0.790 1.000

Wb, in 16 18 22 26 28 28 9 1.000 1.128Wt, in 12 12 16 20 42 42 10 1.270 1.270hft, in 4 6 7 8 5 5 11 1.560 1.410hfb, in 5 6 7 8 8 8

BT-54 BT-63 BT-72 f'c ββ1

h, in 54 63 72 4000 0.85

Sections Ac, in2 659 713 767 5000 0.80

Ig, in4 268,077 392,638 545,894 6000 0.75

ybottom, in 27.63 32.12 36.6 7000 0.70

Properties wo, plf 686 743 799 8000 0.65

Wb, in 26 26 26Wt, in 42 42 42

Look-up Tables for AASHTO and Bulb-tee Girders

Area of Steel

Bulb Tee Girders

AASHTO Bridge Girders

Appendix

A1 A2 A3 Filler Bearing Type Additional Descriptions Details Dwgs

Continuous. Use as per dwgs, or extend min

4 strands from girder into the diaphragm.

13 mm performed

cork

12 mm, preformed Not Continuous. Deck Slab is Continuous

joint filler over the intermediate Bents.

Premolded joint

filler

Not Continuous.PB provide for LL and DL -ve M.

The +M section of PB is designed for SS only.

No Standards for PB diaphragms, shown are for

bridges built with the NEBT Girders.

Diaphragm keyed into pier, surrounded by closed 25

mm cell foam NEBT.

Not Continuous. Slab designed

to assess for continuity.

Filler Diaphragm keyed into pier 300 mm by a dowel bar

under diaphragm extended the strands into diaphragm for +M

Not Continuous. Slab designed

to assess for continuity.

Laminated

elastomeric pad

Not Continuous. Extended Prestressed strands.

min 300 mm to a max 375 mm into the diaphragm

250 mm (+M)

100 mm (no +M)

Foam under

Diaphragm

Foam under No Standards for PB, shown was used on

Diaphragm individual bridges.

1/2'' Premolded

joint filler

PB assumed SS for DL and continuous for LL.

R/C Diaphragm encasing ends of girder.

ContinuousExtends strands from girder into the diaphragm.

Notes PB = Pre-stressed Beam

A1 = Total Diaphragm Width

A2 = Clear Space between the Two girders

A3 = Space usually filled with cardboard or preformed filled

when Deck is designed to account for continuity

+M = Positive Moment

-M = Negative Moment

SS = Simple Span

NEBT = New England Bulb Tee Beam

"-" = Not Available

Elastomeric pad Continuous

Elastomeric pad600 150 - -

Elastomeric pad

-3'-8''

Diaphragm Dimensions Additional Descrition

Colorado 3'-0'' - - - -

States

Delaware 634 mm 280 mm - -

A1.1

Continuous

A1.3

A1.2

Georgia

Idaho

Kansas

Kentucky

Illinois

Louisiana

Maine

Massachusetts

Michigan

Minnesota

North Carolina

North Dakota

Ohio

New Jersey

Missouri

Oregon

Pennsylvania

Tennessee

Utah

Virginia

Washington

Wisconsin

wyoming

612 mm -

-205 mm-

A1.7

-

-

-

-

Elastomeric pad

-

Continuous

Continuous

-

A1.24

A1.25

A1.8

A1.9

A1.10

A1.13

A1.23

A1.18

A1.19

A1.20

A1.14

A1.12

A1.21

A1.11

joint filler

-

Continuous

A1.22

A1.17

A1.15

A1.16

Continuous

Continuous

Styrofoam

650 mm 300 mm

- -

- -

Neoprene pad -

750 mm -

250 mm -

-

-

-

-

1/2'' joint filler

0'-2'' Polystrene

12 mm cardboard

-

-

Elastomeric pad

Elastomeric pad

-

- 300 mm -

2'-3'' 0'-7''

2'-6'' 0'-10'' - -

1'-0'' -

Elastomeric pad

2'-6''

-

2'-0'' 0'-9'' - -

635 mm 520 mm -

-

750 mm

No Standards for PB diaphragms.

Elastomeric pad600 mm - -

450 mm 150 mm -

900 mm 250 mm -

-

-

-

-

300 mm - -

Elastomeric pad

Continuous

Not official works, but frequently used.

Not Continuous. PB designed as SS for DL and LL.

760 mm

Polystrene

300 mm

-

bearings pads

--1'-0''

2'-0'' -

Not Continuous. Concrete Diaphragm Between PB. A1.4

A1.6

Continuous A1.5

300 mm -

2'-4'' 0'-4''

California

New York State

1'-8'' 0'-3''

-

A1.26

A1.27Continuous-

- Elastomeric pad Continuous

Alaska 600 mm 300 mm -

Table of Survey Summary and Commentary

- - N/A

--250 mm

- Continuous100 mm

Colorado Appendix A1.1

Delaware Appendix A1.2

Georgia Appendix A1.3

Georgia Appendix A1.3.1

Idaho Appendix A1.4

Illinois Appendix A1.5

Illinois Appendix A1.5.1

Illinois Appendix A1.5.2

Kansas Appendix A1.6

Kansas Appendix A1.6.1

Kentucky Appendix A1.7

Kentucky Appendix A1.7.1

Louisiana Appendix A1.8

Louisiana Appendix A1.8.1

Maine Appendix A1.9

Massachusetts Appendix A1.10

NEBT Beam Continuity

Massachusetts Appendix A1.10.1

Box Beam Continuity

Massachusetts Appendix A1.10.2

Pier Diaphragm Plan For Box Beam Continuity

Michigan Appendix A1.11

Minnesota Appendix A1.12

Missouri Appendix A1.13

New Jersey Appendix A1.14

North Carolina Appendix A1.15

North Dakota Appendix A1.16

Ohio Appendix A1.17

Ohio Appendix A1.17.1

Oregon Appendix A1.18

Pennsylvania Appendix A1.19

Tennessee Appendix A1.20

Utah Appendix A1.21

Virginia Appendix A1.22

Washington State Appendix A1.23

Wisconsin Appendix A1.24

Wyoming Appendix A1.25

California Appendix A1.26

State Of New York Appendix A1.27