Application of Infrared Thermography for Damare Detction19

8/6/2019 Application of Infrared Thermography for Damare Detction19

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APPLICATION OF INFRARED

THERMOGRAPHY FOR DAMAGEDETCTION IN STRUCTURAL

CONCRETE


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INFRARED THERMOGRAPHY

y Regardless of the building type

involved, infraredthermography can provide

remarkable nondestructive

information about construction

details and building performance.


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INFRARED THERMOGRAPHYy Thermography is the use of

an infrared imaging and

measurement camera to"see" and "measure

thermal energy emitted

from an object.


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HEAT LOSS FROM FOUNDATIONy Thermal, or infrared

energy, is light that is not

visible to the human eye.It's the part of the

electromagnetic spectrum

that we perceive as heat.

y

Unlike visible light, in theinfrared world everything

with a temperature above

absolute zero emits heat.


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NEEDS OF INFRARED

THERMOGRAPHYAn accurate

Inexpensive

Non-destructive

Non-labor intensive method


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INFRARED THERMOGRAPHYy Temperature profiling of a surface or point

y Infrared technique

y Black body radiationy Wavelength 0.8m-1000m


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INFRARED IN ELECTROMAGNETIC

SPECTRUM


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OBJECTIVELocating voids

Honeycombing

Plaster voids Interconnection of

carbon-fiber

reinforcement

bituminous sealing onsteel


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SOURCE OF HEAT Artificially applied heat

The suns Radiant heat and thermal effects


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THERMOGRAPHY INSTRUMENT


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THEORY Kirchhoffs law:

= E/Es

Planck radiation law:M (,T)=(2hc2)/(5.( hc/kT-1))

Wien displacement law:

max

=2898/T

Stefan and Boltzmann

I =T4

E= emissivity of a real body

Es=emissivity of the black

body

= emission coefficient=wave length

T= the absolute

temperature

h=the Planck constant

c= the speed of light.

M =the specific spectralradiation

= 5.67x10 -8 W m-2 K-4.

I=radiant power


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CONSTRUCTION THERMOGRAPHYy Emission coefficients MATERIAL

Concrete 0.94

Sand 0.93

Brick 0.93-0.94

Limestone 0.96

Render/plaster 0.90-0.96

Glass 0.93-0.96

Wood 0.96Roofing felt 0.93

Gypsum 0.90

Paint 0.90-0.95

Clay 0.95

Brickearth 0.93


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EXPERIMENT SETUP


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Experimental set-up to perform

thermo-gram


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IMAGE AND TIME LAPSE SPECIFIED

IMAGE NUMBER 1 2 3 4 5 6 7 8

LAPSE TIME Ts in

minutes(t srart=t 0=0)

0 26 90 210 266 354 394

Transit (Tn) steady-

state(Ss)

Tn Tn Tn Tn Tn Tn Ss Ss


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NUMERICAL SIMULATION

3D differential equation of Fourier

Where,

Mass density

Thermal conductivity

Heat capacity Cp

trmpareture T


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THE NUTSAND BOLTSOF DATA

COLLECTION AND REPORTING

y Grouted and non-grouted

y heat and cool


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INFRARED CAMERA


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MISSING INSULATON(CEILING)


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AIR LEACKAGE

LOCATIONEXCESSIVE AIR LEAKAGE CANACCOUNT FOR HALF OF THEENERGY CONSUMED TOCONDITIONED BUILDINGS.

THE PROBLEMS CAN BE AS

STRAIGHTFORWARD AS A FAILEDDOOR WEATHERSEAL

THIS IMAGE IS OF A SLIDINGGLASS DOOR.THE CORNER AT THEADJACENT WALL WAS NOTNSULATED AND THERE WAS POORWEATHER SEALS ON THE DOOR.

NOTE THE TEMPERATUREDIFFERENCE BETWEEN THE WALL77 FTAND THE BOTTOM OF THEDOOR 31.4 F


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MOISTURE

INTRUSION OR

CONDENSATION As building designs and

techniques produce tighter

thermal envelopes, moisture

has created more and more

problems.

The water can intrude

through a small crack and is

then trapped between the

relatively impermeable

building materials.

Good building techniquestypically must deal with

both air sealing and

moisture retarders to keep

moisture from accumulating

insides the wall sections


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CONDENSATION THOUGHT TO BE A

ROOF LEAKCeiling and drywall damage

Condensation where insulationwas disrupted


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ROOFINGy From the looks of this

image it appears that the

roof being surveyed has a

significant amount of wet

insulation; red and yellow

outlined areas.

y Yet in reallity,there was no

wet insulations

throughout the entire

roof.


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CONCRET MASONRY WALL

Photograph of CMU wall


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Thermograph of CMU wall with

improper placement of grout


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Thermographic investigation a heat

bridge with the growth of mold

including a thermo gram


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Localization of the position of floor

heating cables in the living room


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os on o e p pes o a wa

heater, operating with geothermal

heat.


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ADVANTAGESy non-contact

y Fast, reliable & accurate output

y A large surface area can be scanned in no time.y Presented in visual & digital form.

y Software back-up for image processing and analysis.

y Requires very little skill for monitoring.


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NECESSITY IS THE MOTHER OF

INVENTION


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Application of Infrared Thermography for Damare Detction19