Transcript
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SEMINAR REPORT ONNON DESTRUCTIVE TEST
Presented by
Timmareddy
VIII sem civil engg
under guide
prof ; RENUKASWAMY GAVAI
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INTRODUCTION
NEED FOR TESTING
VISUAL INSPECTION FOR NDT TESTING
NDT METHOD OF TESTING
CONCLUSION
CONTENTES
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The quality of product was checked & evaluated by
NDT method .
most of the materials made of concrete such as
buildings,tunnels,dams,bridges etc
NDT as ability to determine the strength &
durability of critical construction without
damaging them
The main advantages is the quality of concrete
structure is determine without damaging
INTRODUCTION
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Proposed change of usage or extension of a
structure
Acceptability of a structure for purchase
Acceptability of a structure for insurance
To test the material components without
disturbing its excites
Monitoring long-term changes in material
properties and structural performance
NEED FOR TESTING
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Visual inspection is very important to knowing structure details about any defects in concrete .to note any presences of cracking and the cracking type .
History of the structure
VISUAL INSPECTION FOR NDT TESTING
6Fig 3: Serious crack at building structure. Fig 4: Exposed bar
Fig 1: Serious cracks at bridge structure
Fig 2: Watermark indicates leak
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There are several NDT methods are applicable to concrete structure
METHOD OF NDT TESTINGS
1. Ultrasonic pulse velocity test
2. Rebound test
3. Rebar detective test
4. Rebar corrosion detective test
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Used to asses the quality and strength of in-situ
concrete in structural member.
Its used to check the compaction of
concrete,uniformity,determination of cracks
PUNDIT (portable ultrasonic NON-destructive digital
indicating tester ) from U.K
Consists of a pair of transducers (probes) of different
frequencies, electrical pulse generatet,eletrical timing
devices and cables.
It’s based on the through-transmission technique.
ULTRASONIC PULS VELOCITY TEST
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Portable Ultrasonic Nondestructive Digital Indicative
Technique (PUNDIT)
Size: 180 X 110 X 160mm
Weight 3kg
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PUNDITH METHOD OF TESTING
1. DIRECT METHOD
2. IN DIRECT METHOD
3. SEMI DIRECT METHOD
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DIRECT METHOD
SEMI-DIRECT METHOD
INDIRECT METHOD
PUNDITH METHODS
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Pulse velocity will be measured in concrete by placing “TRANSDUCERS ACROSS” the member exactly opposite to each other.
DIRECT METHOD
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INDIRECT METHOD
Pulse velocity will be measured in concrete by placing transducers on the SAME PLANE of the member
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Pulse velocity will be measured in concrete by placing transducers intermediate between those of the other two method.
SEMI DIRECT METHOD
SEMI-DIRECT TRANSMISSION OF PULSE IN R.C.DECK
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METHOD OF CALCULATION OF PULSE VELOCITY
Velocity = distance traveled / path lengthTime taken
Pulse Velocity in concrete will be represented in Km/sec.Classification of the quality of concrete on the basis of the pulse velocityPLUSE VELOCITY (KM/SEC) QUALITY OF CONCRETE
ABOVE 4.5 EXCELLENT
3.5 TO 4.5 GOOD
3.1 TO 3.5 POOR
BELOW 3.O VERY POOR
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This is quick method or assessing the quality
of concrete based on the surface hardness
indicated by the rebound number.
An higher rebound value indicates the higher
strength or surface hardness of concrete.
This equipment works based on the spring
controlled hammer mass or slides on a
plunger within a tubular housing.
REBOUND HAMMER TEST
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Fig: Rebound Hammer.Weight < 2Kg
Impact Energy = 2.2Nm
Suitability 20 – 60 MPa
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REBOUND HAMMER WORKING
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METHOD OF TESTING Rebounb hammer can be used on the
concrete surface at five different positions for assessment of surface hardness and strength estimation at site depending on the availability of exposed surface of concrete.
oHORIZONTAL
oVERTICALLY UPWARDS
oVERTICALLY DOWNWARDS
oINCLINED VERTICALLY UPWARDS
oINCLINED VERTICAL DOWNWARDS
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Fig: Testing by Rebound Hammer
by Horizantal
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POSITION OF REBOUND HAMMER - VERTICAL UPWARDS
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POSITION OF REBOUND HAMMER - VERTICAL DOWNWARDS
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DIGITAL REBOUND HAMMER
REBOUND HAMMER
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REBAR DETECTIVE TEST
The PROFOMETER 5 locates reinforcing bars,
spacing of bar, complete accuracy.
It also helps in preparing structural drawing of
the structural member in the absence of
details about the building.
This is works on electromagnetic principle
equipment consists of display unit coupled
with probes of different types
The identified concrete surface will be cleaned
such that it if free from dust, oil,
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ESTIMATION OF COVER AND MAPPING OF REBARS IN ABUTMENT
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ESTIMATION OF COVER AND MAPPING OF REBARS IN BEAM
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DISPLAY VIEW ONLY
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The method of half cell potential measurements normally involves measuring the potential of an embedded reinforcing bar.
This is usually a copper / copper sulphate, or silver /silver chloride cell
EQUIPMENTS RAE USED HALF CELL ELECTRICAL JUNCTION DEVIES VOLTMETER ELECTRICAL LEAD WIRES
REBAR CAROSSIVE
DETECTIVE TEST
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Potential difference level (m v)
Chances of rebar corroded
Less than -500 Visible evidence of corrosion
-350 to -500 95%
-200 to -350 50%
More then -200 05%
RISK OF CORROSION AGAINST THE POTENTIAL DIFFERENCES READING
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Non destructive test are relatively performed in
concrete structure
The quality of product was checked & evaluated
by NDT method without disturbing the structure
NDT now considered as a powerful method for
evaluating existing concrete structure
Cover meter is the method from which
approximate mapping of the structure can be
done
CONCLUSION
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