AN ADJACENT BOX BEAM BRIDGE - IN.gov

SPR 4009 Box Beam Study 2/14/2019

1

ADJACENT PRESTRESSED,

PRECAST BOX BEAM BRIDGES

RYAN WHELCHEL, Purdue University

RYAN MOLLEY, KPFF

LUIS FELIPE URREGO, Universidad de los Andes

ROBERT FROSCH, Purdue University

CHRISTOPHER WILLIAMS, Purdue University

1

2

• Box Girders

• Shear Keys

• Tie Rods

• Wearing Surface

AN ADJACENT BOX BEAM BRIDGE

2

1

2


2

PROJECT MOTIVATION

• History of poor durability and performance

• Economical and simple to build

• Over 43,000 in US and 4,000 in Indiana

3

RESEARCH PLAN

• Acquire decommissioned bridge girders

• Research and acquire NDT equipment

• Conduct non‐destructive evaluation

• Perform structural tests

• Load test an existing bridge to determine load

distribution of a non‐composite deck on a

bridge without shear keys

4

3

4


3

SPECIMEN ACQUISITION

• Determine those bridges that will be replaced

• Inspect bridges to determine specimen quality

• Contact County, Engineer, or Contractor to

coordinate girder salvage

5

COMMON DETERIORATION

• Longitudinal Cracking • Exposed or Broken Strand

6

5

6


4

7

BOX BEAM SPECIMENS

Wells Co. Bridge 79

7

8

BOX BEAM SPECIMENS

Newton Co. Bridge K5

8

7

8


5

9

BOX BEAM SPECIMENS

Elkhart Co. Bridge 102

9

NONDESTRUCTIVE TESTING

9

10


6

NON‐DESTRUCTIVE EVALUATION (NDE)

Ground Penetrating Radar (GPR)

Connectionless Electrical Pulse Response Analysis

(CEPRA)

Half‐cell potential measurement

11

PRELIMINARY NDE RESULTS

Specimen 409‐1‐ESSpan: 50’Depth: 29”Width: 36”

12

11

12


7


Connectionless Electrical Pulse Response Analysis

Low Moderate High

0

5.1

10.3

15.4

20.6

25.7

30.9

36.0

0 5 10 15 20 25 30 35 40 45 50

Tra

nsve

rse

Loca

tion

(in.)

Longitudinal Location (ft)

13


Half‐cell potential measurement

0

5.1

10.3

15.4

20.6

25.7

30.9

36.0

0 5 10 15 20 25 30 35 40 45 50

Tra

nsve

rse

Loca

tion

(in.)

Longitudinal Location (ft)

Low Moderate High

14

13

14


8

STRUCTURALTESTING

16

BEAM TEST

Load Points

Roller Bearing (TYP)

Reaction Block (TYP)

String Potentiometers (two at midspan)

16

15

16


9

17

BEAM TEST

Specimen 409‐1‐ES

• Three exposed strands at L/8 from support

Specimen 409‐2‐UD

• No damage

~ 12 in.

17

18

BEAM TEST

0

10

20

30

40

50

60

0 5 10 15 20 25

App

lied

For

ce (

kip)

Midspan Deflection (in.)

42 kip - Undamaged Capacity

34 kip - Damaged Capacity

52 kip - Test

47 kip - Theory

18

17

18


10

19

BEAM TEST

0

10

20

30

40

50

60

0 5 10 15 20 25

App

lied

For

ce (

kip)


42 kip - Undamaged Capacity

47 kip - Theory

50 kip - Test

19

20

BEAM TEST

0

10

20

30

40

50

60

0 5 10 15 20 25

App

lied

For

ce (

kip)


52 kip - Test

47 kip - Theory

50 kip - Test

20

19

20


11

FIELD TESTING

TIPPECANOE COUNTY BRIDGE 115

• Built: 1957

• Rehabilitated: 1993

• Span: 40 ft

• Beam Depth: 21 in.

• Beam Width: 45 in.

• 7 Beams

22

21

22


12

INTRODUCTION

INSTRUMENTATION

10’ 10’ 10’ 10’

23

LOADING

Dump Truck

• Weight: ~ 58,000 lb

• 30% to front axle

• 70% to tandem axle

• Wheelbase: 16’ – 4”

24

23

24


13

25

� �

T E S T 1T E S T 2T E S T 3T E S T 4

25

26

Bridge Deck Modifications

• Milling

• Shear Key Cutting

• Surface Preparation

• Bridge Deck Cast

FIELD TESTING

26

25

26


14

27

1 2 3 4 5 6 7

10' 10' 10' 10'

East West

‐0.2

‐0.18

‐0.16

‐0.14

‐0.12

‐0.1

‐0.08

‐0.06

‐0.04

‐0.02

0

1 2 3 4 5 6 7

Midspan

Deflection (in.)

Beam Number

LT1 ‐ Original Condition

LT2 ‐ Asphalt Removed

LT3 ‐ Shear Keys Disabled

LT4 ‐ Concrete Deck Placed

27

28

1 2 3 4 5 6 7

10' 10' 10' 10'

East West

‐0.2

‐0.18

‐0.16

‐0.14

‐0.12

‐0.1

‐0.08

‐0.06

‐0.04

‐0.02

0

1 2 3 4 5 6 7

Midspan

Deflection (in.)

Beam Number

Original Condition

Concrete Deck Placed

35% reduction in deflection

28

27

28


15

LOAD DISTRIBUTION

• The proportion of load carried by a given

beam was calculated as follows

𝐷𝐹∆∑∆

29

10' 10' 10' 10'

East West

1 2 3 4 5 6 7

0%

5%

10%

15%

20%

25%

30%

1 2 3 4 5 6 7

Load

Dis

trib

utio

n

Beam Number

LT01 LT0430

29

30


16

10' 10' 10' 10'

East West

0%

5%

10%

15%

20%

25%

30%

1 2 3 4 5 6 7

Load

Dis

trib

utio

n

Beam Number

LT01 LT04

1 2 3 4 5 6 7

31

LOAD DISTRIBUTION SUMMARY

Load Test Interior Exterior

LT01 22% 23%

LT04 22% 25%

Design Distribution Factors

Interior Exterior

21% 24%

AASHTO LRFD 2017

Load Fraction (truck)

32%

AASHTO Standard Specification 2002

Experimental Distribution Factors

32

31

32


17

FIELD TEST CONCLUSIONS

• Concrete deck restored load distribution to a

code level

• Durability and stiffness were added to the

system

• Composite action between the deck and the

beams was achieved

33

IMPLICATIONS TO BEST PRACTICE

• Recommend all new construction use

concrete decks

• Potential new design of adjacent box

beam bridges without shear keys

Concrete Deck Sealant

Standard Box Beam Shape

34

33

34


18

PROJECT BENEFITS

• Improved inspection capability for bridge

inspectors

• Increase in bridge load rating accuracy

• Development of next generation box beams

35

ACKNOWLEDGMENTS

35

36


19

THANK YOU

37

Documents

AN ADJACENT BOX BEAM BRIDGE - IN.gov