This document discusses damage identification and structural health monitoring of bridges. It provides an overview of the importance of structural health monitoring to identify damage in bridges. Various non-destructive testing methods that can be used for structural health monitoring of bridges are described, including impact echo, ultrasonic pulse velocity, rebound hammer, impulse response, acoustic emission, ground penetrating radar, half cell potential, electrical resistivity, and infrared thermography. The document also discusses experimental and analytical approaches to structural health monitoring and identifies some gaps in current research, with the objective of monitoring and analyzing the health of bridges using non-destructive testing to identify damages and recommend remedial measures.

1. DAMAGE IDENTIFICATION AND
STRUCTURAL HEALTH
MONITORING OF BRIDGES

2. INDEX
• Introduction
• Importance
• Literature review
• Gap areas identified
• Research objective
• Methodology
• Current status of work
• References

3. STRUCTURAL HEALTH
MONITORING
• Process of implementing damage identification strategy
• Damage includes changes to materials and geometric
properties including boundary conditions and system
connectivity
Damage Identification Process:
• Detection
• Location
• Charaterisation
• Extent

4. IMPORTANCE
• According to US survey (FHWA) 28% out of 59500
bridges are deficient/damaged
• Severe damage lead to collapse which further leads to
devastation and inconvenience
• Heavy expenditures in reconstruction/new construction
• Retro-fitting require deterioration details like extent,
location and its type

5. TYPES OF MONITORING
ON THE BASIS OF TIME ON THE BASIS OF SCALE
Short Term Local
Long Term Member
Inspection Global
Early Warning
Collapse Warning

6. LITERATURE REVIEW
Experimental
Approach
Analytical
Approach

7. EXPERIMENTALAPPROACH

8. VARIOUS METHODS OF SHM OF
CONCRETE BRIDGES
• Impact echo
• Ultrasonic pulse velocity
• Rebound hammer
• Impulse response
• Acoustic emission
• Ground penetrating radar
• Half cell potential
• Electrical resistivity
• Infrared thermography

9. IMPACT ECHO
• Principle: Transmission and reflection of
electromagnetic waves
• Uses: Detection of voids, cracks, delamination,
unconsolidated concrete, and debonding
Determining thickness
• Advantages : Able to detect condition of concrete
accessible from one side only, quick, accurate, and
reliable.
• Limitations: Decreases with increase in thickness,
and accuracy depends on impact duration.

10. IMPACT ECHO METHOD

11. ULTRASONIC PULSE
VELOCITY
• Principle: Ultrasonic wave velocity and its
attenuation.
• Uses: Homogeneity of concrete, cracks, voids and
strength determination
• Advantages : Quick, portable, large penetration
depth, simple interpretation, and moderate cost.
• Limitations: Not very reliable, moisture variation
and presence of reinforcement can affect results.

12. ULTRASONIC PULSE VELOCITY

13. REBOUND HAMMER
• Principle: Rebound of plunger when struck with
concrete indicates strength.
• Uses: Determining compressive strength and surface
hardness
• Advantages : Simple, quick, and inexpensive.
• Limitations: Not so reliable, smoothness, age of
concrete, carbonation, and moisture content can affect
results.

14. REBOUND HAMMER

15. IMPULSE RESPONSE
• Principle: Based on stress wave test method.
• Uses: Detecting voids under concrete and reinforced
slabs laid on the ground, delamination, honeycombing
in concrete elements and checking the length and
continuity of piles.
• Advantages : Simple, easy to handle.
• Limitations: Depends on the skill of user, and deep
damages influence the results.

16. IMPULSE RESPONSE

17. ACOUSTIC EMISSION
• Principle: Sudden distribution of stresses
generates elastic waves.
• Uses: Cracks, Delamination and Corrosion
• Advantages : Fast results, detect changes in
materials.
• Limitations: Costly, defects already present
are not detected.

18. ACOUSTIC EMISSION

19. GROUND-PENETRATING RADAR
• Principle: Propagation of radiofrequency (0.5 to 2
GHZ).
• Uses: Concrete mapping, mining, geotechnical,
road, and bridge Forensics, Detection of voids,
honeycombing, Delamination and Moisture content
• Advantages : Low cost, portable, effective.
• Limitations: Complex results, difficult
interpretations.

20. GROUND-COUPLED PENETRATING RADAR

21. HALF-CELL POTENTIAL
• Principle: Electric potential of rebars is measured
relative to half cell and indicates probability of
corrosion.
• Uses: Detect corrosion state in concrete
reinforcement and Corrosion rate
• Advantages : Simple, portable, results in the
form of equipotential contours.
• Limitations: Needs preparation, saturation
required, not very accurate, and time consuming.

22. HALF-CELL POTENTIAL

23. INFRARED THERMOGRAPHY
• Principle: Surface, temperature variation.
• Uses: Detection of thermal differences,
delamination, cracks, voids
• Advantages : Easy interpretation, simple, safe, no
radiation, rapid setup, and portable.
• Limitations: thickness of defects, and results
affected by environmental conditions.

24. INFRARED THERMOGRAPHY

25. STANDARD CODES FOR NDT
S.NO. TEST/PARAMETERS STANDARD CODES
1. Impact echo method ASTM C1383-98a
2. Ultrasonic pulse velocity IS 13311 (Part 1): 1992, ASTM C597-
97, BS 1881: Part 203: 1986, BS 4408:
pt. 5, NDIS 2416-1993
3. Rebound hammer IS 13311 (Part 2): 1992, ASTM C805-
97, BS 1881 Part 202: 1986, EDIN EN
12398 (1996), ISO/CD 8045
4. Ground penetrating radar ASTM D6087-97
5. Half-cell potential ASTM C876-91
6. Infrared thermography ASTM D4788-88

26. ANALYTICALAPPROACH

27. DIFFERENT MATHEMATICAL
MODELS
• Straight line extrapolation
• Regression model
• Curve-fitting model
• Probability distribution
• Markov model

28. GAPAREAS IDENTIFIED
• Tests were performed on the samples prepared in the laboratory
and not on the real structure
• Tests were carried out on the components of the structure
• Corrosion tests were performed only with chloride ingress factor
• Requirement of sensors is very high and these are very
expensive
• Mathematical models are based on assumptions

29. RESEARCH OBJECTIVES
• To monitor and analyze the health of reinforced
concrete bridges using non-destructive tests
• To identify the damages present and suggesting
some remedial measures for the improvement

30. METHODOLOGY
Visual inspection
Interaction at site
Application of NDT tests
Analysis of results
Damage identification and
suggestions

31. REFERENCES
• Annan, A. 2003. “Ground penetrating radar principles, procedures, and applications.”
Sensor and Software, Inc., Ontario, Canada.
• Hellier, C. 2001. Handbook of nondestructive evaluation, McGraw-Hill, New York
• Loulizi, A. 2001. “Development of ground penetrating radar signal modeling and
implementation for transportation infrastructure assessment.” Ph.D. thesis, Virginia
Polytechnic Institute and State University, Blacksburg, Va.
• Ryall, M. J. 2003. Bridge management, Butterworth-Heinemann, Newton, Mass.
• Washer, G. 2003. “Nondestructive evaluation of highway bridges in the United States.”
Proc., Int. Symp. on Nondestructive Testing in Civil Engineering, German Society for Non-
Destructive Testing, Berlin.
• Zhao, Y., Wu, J., Wang, J., and Wan, M. 2001. “Ground penetrating radar techniques and
its application in nondestructive testing of reinforced concrete.” Proc., 10th Asia–Pacific
Conf. on Nondestructive Testing, Australian Institute for Nondestructive Testing,
Brisbane, Australia.
• Rhazi, J., Dous, O., and Ballivy, G. 2003. “Nondestructive health evaluation of concrete
bridge decks by GPR and half-cell potential techniques.” Proc., Int. Symp. on
Nondestructive Testing in Civil Engineering, Berlin, Germany.

32. CONTINUED……
• K. L. Rens and T. Kim, “Inspection of Quebec street bridge in Denver, Colardo: destructive and
nondestru testing,” Journal of Performance of Constructed Facilities, vol. 21, no. 3, pp. 215–224,
2007.
• S. S. Bhadauria andD. M. C.Gupta, “In situ performance testing of deteriorating water tanks for
durability assessment,” Journal of Performance of Constructed Facilities, vol. 21, no. 3, pp. 234–239,
2007.
• L. Amleh and M. S. Mirza, “Corrosion response of a decommissioned deteriorated bridge deck,”
Journal of Performance of Constructed Facilities, vol. 18, no. 4, pp. 185–194, 2004.
• W. P. S.Dias and A. D. C. Jayanandana, “Condition assessment of a deteriorated cement works,”
Journal of Performance of Constructed Facilities, vol. 17, no. 4, pp. 188–195, 2003.
• M. K. Lim and H. Cao, “Combining multiple NDT methods to improve testing effectiveness,”
Construction and Building Materials, vol. 38, pp. 1310–1315, 2013.
• D. M. McCann and M. C. Forde, “Review of NDT methods in the assessment of concrete and masonry
structures,” NDT and E International, vol. 34, no. 2, pp. 71–84, 2001.
• D. Breysse, G. Klysz, X. D´erobert, C. Sirieix, and J. F. Lataste, “How to combine several non-
destructive techniques for a better assessment of concrete structures,” Cement and Concrete
Research, vol. 38, no. 6, pp. 783–793, 2008.
• T. Shiotani, D. G. Aggelis, and O. Makishima, “Global monitoring of large concrete structures using
acoustic emission and ultrasonic techniques: case study,” Journal of Bridge Engineering, vol. 14, no.
3, pp. 188–192, 2009.