This document discusses using infrared thermography (IRT) to detect damage in structural concrete. IRT detects infrared radiation emitted from objects and converts it to a thermal image using an IR camera. The document describes active IRT, which uses an external heat source, and passive IRT, which relies on ambient heat. An experiment is presented using active IRT to detect defects in a concrete specimen by monitoring temperature distribution during heating. IRT has many applications in construction, security, navigation, law enforcement and more due to its non-contact inspection ability and potential to detect subsurface issues.

1. INFRARED THERMOGRAPHY FOR
DAMAGE DETECTION IN
STRUCTURAL CONCRETE
PRESENTED BY: GUIDE:

2. CONTENTS
1. INTRODUCTION
2. INFRARED THERMOGRAPHY
3. INFRARED RADIATION
4. IR CAMERA
5. TYPED OF THERMOGRAPHY
1. ACTIVE THERMOGRAPHY
2. PASSIVE THERMOGRAPHY
6. COLOUR REPRESENTATION
7. EXPERIMENTAL SETUP
8. RESULTS
9. OTHER APPLICATIONS
10. ADVANTAGES& DISADVANTAGES

3. INTRODUTION
 Infrared thermography(IRT) is the method, which
detects infrared energy emitted from object and
converts it to temperature
 The thermal image is produced by means of infrared
camera which detects the infrared radiation
 In this, discuss about some application of IRT and the
detection of defects in a concrete specimen

4. Hot and cold water

5. INFRARED THERMOGRAPHY
 Infrared thermography(IRT) is the method,
which detects infrared energy emitted from
object, converts it to temperature
 “IRT” is simply taking pictures of temperatures
 A non-contact , image based method to
examine temperature or thermal patterns in
objects

6. INFRARED RADIATION
 Infrared radiation (IR), is a region of the
electromagnetic radiation spectrum where
wavelengths range from about 700 nanometers to 1
millimeter
 Infrared rays is everywhere, where ever sunlight
reaches (by direct or by scattering)
 All objects having heat emits EM radiation as their

7. IR CAMERA
The camera converts radiated heat energy into an
electrical signal and displays the thermal image
Thermal images can be obtained in total darkness
Because the camera only depends upon the temperature
of the object

8. INFRARED SYSTEM

9. CONT.
The lens is made of germanium , because the glass
doesn’t pass IR waves,it pass only low wavelength
radiations
It has reasonable cost
It has a long distance range

10. TYPES OF THERMOGRAPHY
1. ACTIVE THERMOGRAPHY
 The active thermograph is frequently chosen to
examine the inside of a building, using an external
source of IR radiation and these can be gained by
meansof externalheating.

11. 2. PASSIVE THERMOGRAPHY
This method isuseddirectly in the presenceof solar
radiation. It doesn’t require anyexternalof heating.
 Its usedto examineexterior of building mainly for the
diagnosis of building

12. Colour representation
Colour shade represents the different temperature
zones
Variety of image palette can be selected from IR
camera

13. EXPERIMENTAL SETUP
 A concrete specimen having defects is arranged for this
(0.5x0.5x0.10 m)
 The polystyrene defects are in it, two discs and a
rhombus(thickness= 4cm)
 The thermal stimulation of the specimen is monitored

14. CONT.
 The existence of inhomogeneties, affects the heat
transfer and causes temperature distribution
 The active thermography is used here.
 As the external source of thermal excitation ,1000 W
halogen lamp is used for 45-60 min
 Thermal excitation distance upto 1.5 – 3 meter

15. CONT.
After heating the thermal image is taken
by IR camera
Experimental setup of the thermal excitation, heating distance
of 1.5 m from the specimen surface

16. RESULTS
The inhomogeneties or defects in the specimen
is examined
The temperature distribution in the material is
found
The shape of defect and the position can be
monitored.

17. CONT.
The concrete having different compressive
strengths, the defects can be detected
 FIG 1& FIG 2 having M20 &M40 respectively

18. CONT.
Existence of reinforcements affects the possibility of
detecting damage
Defect under dense reinforcements decrease the
possibility of detecting the defect
• Having with and without the reinforcements

19. OTHER APPLICATIONS OF IRT
1. BUILT ENVIRONMENT
a) Measure heat loss
b) Detect hot or cold spot
c) Detect electrical hot spot
d) Examine pipe behind wall
e) Detect source of seepage & moisture presence
etc.
f) Other concrete structure inspections

20. CONT.
Cavities or holes
2. IN BIOLOGICAL
 Detect living creatures in poor visibilities
 Can be used instead of mammography
 Oncology
 Neuromuscular diseases

21. CONT.
3. IN SECURITY
 Detect camouflaged targets in darkness
 Security breach
 In fire and rescue

22. CONT.
4. IN NAVIGATION
 in car rear camera ,detect heat signatures in blind
spot
 Search and rescue operation in sea
5. IN LAW ENFORCEMENT
 Can detect hiders beyond smoke and fog
THERMAL VISIBLE(FOG)

23. CONT.
 indoor and out door marijuana cultivation can be
easily spotted

24. 6. TOURISM
7. ELECTRICAL POWER PLANT etc.

25. ADVANTAGES
1. Fast inspection rate
2. Non-contact method
3. No harmful radiation produced
4. Easy to interpret
5. Wide area of application
6. Cheap rate
7. A large surface area can be scanned in no time
8. Presented in visual & digital form
9. Software back-up for image processing and analysis

26. DISADVANTAGES
1. In active IRT often non-uniform heating
occurs
2. Thermal losses of specimen
3. Mostly surface defects only detects
4. Unable to detect the inside temperature if
the medium is separated by glass/polythene
material

27. CONCLUSION
By infrared thermography ,can detect the heat
signatures of anything that emits the heat
In construction industry it is useful to detect the
surface defects and to a certain thickness of
concrete ,the heat signatures can be monitored
So the diagnosis of building and other structures
can be conducted
It has many advantages and wide application in
many fields so the use of IR camera is largerly
used