Ultrasonic pulse velocity testing, rebound hammer testing, and cover meter testing are three common non-destructive testing methods for concrete structures. Ultrasonic pulse velocity testing uses transducers to transmit and receive ultrasonic pulses through concrete to assess properties like strength and uniformity without damage. Rebound hammer testing measures surface hardness through a spring-controlled hammer's rebound, indicating relative concrete strength. Cover meters use electromagnetic principles to locate and measure rebar cover thickness in concrete. Non-destructive testing provides important information on structural condition and performance without damaging the structure.

1. NON-DESTRUCTIVE TESTINGNON-DESTRUCTIVE TESTING
OF CONCRETE IN STRUCTURESOF CONCRETE IN STRUCTURES
Prepared by :Prepared by : Guided by:Guided by:
NAVEEN S KADAM Prof. CM PATILNAVEEN S KADAM Prof. CM PATIL
VIII Semester Dept. of Civil EngineeringVIII Semester Dept. of Civil Engineering
Dept. of Civil EngineeringDept. of Civil Engineering

2. • The usual way of testing concrete is by meansThe usual way of testing concrete is by means
of casting cubes and then crushing them.of casting cubes and then crushing them.
• The quality of product in the field is checkedThe quality of product in the field is checked
by non-destructive methods.by non-destructive methods.
• The main advantage is determination ofThe main advantage is determination of
concrete properties without damage.concrete properties without damage.
INTRODUCTION :INTRODUCTION :

3. NEED FOR TESTING :NEED FOR TESTING :
• Monitoring long-term changes in materialMonitoring long-term changes in material
properties and structural performance.properties and structural performance.
• To check for the workmanship.To check for the workmanship.
• For remedial schemes and repairs.For remedial schemes and repairs.
• To check for design specification.To check for design specification.

4. TESTINGTESTING
NON-NON-
DESTRUCTIVEDESTRUCTIVE
SEMI / PARTIAL DESTRUCTIVE TESTSEMI / PARTIAL DESTRUCTIVE TEST
DESTRUCTIVEDESTRUCTIVE
TYPES OFTYPES OF
TESTING :TESTING :

5. NON-DESTRUCTIVE TESTING :NON-DESTRUCTIVE TESTING :
Common Methods:Common Methods:
1.1. Ultrasonic Pulse Velocity TestUltrasonic Pulse Velocity Test
2.2. Rebound Hammer TestRebound Hammer Test
3.3. Cover Meter TestCover Meter Test

6. 1. Ultrasonic Pulse Velocity Test1. Ultrasonic Pulse Velocity Test ::
• used to assess the quality and strength of in-used to assess the quality and strength of in-
situ concrete in structural members.situ concrete in structural members.
• used to check the compaction of concrete,used to check the compaction of concrete,
uniformity of concrete, determination ofuniformity of concrete, determination of
cracks, presence of honeycombs, level ofcracks, presence of honeycombs, level of
deterioration and also strength estimationdeterioration and also strength estimation
(qualitatively).(qualitatively).
Contd/……

7. PUNDIT (Portable Ultrasonic Non-Destructive DigitalPUNDIT (Portable Ultrasonic Non-Destructive Digital
Indicating Tester)Indicating Tester)
• consists of a pair of transducers (probes) ofconsists of a pair of transducers (probes) of
different frequencies, electrical pulse generator,different frequencies, electrical pulse generator,
electrical timing device and cables.electrical timing device and cables.
• It is based on the through-transmissionIt is based on the through-transmission
technique.technique.

8. Portable Ultrasonic Nondestructive DigitalPortable Ultrasonic Nondestructive Digital
Indicative TechniqueIndicative Technique ((PUNDITPUNDIT))
Size: 180 X 110 X 160mmSize: 180 X 110 X 160mm
Weight: 3kgWeight: 3kg
Digital display with Accuracy ±0.1 microsecondsDigital display with Accuracy ±0.1 microseconds

9. METHODS OF TESTING :METHODS OF TESTING :
1.1. Direct transmissionDirect transmission
2.2. Indirect transmissionIndirect transmission
3.3. Semi-direct transmissionSemi-direct transmission

10. DIRECT TRANSMISSION :DIRECT TRANSMISSION :
• Pulse velocity will be measured in concrete byPulse velocity will be measured in concrete by
placingplacing transducers acrosstransducers across the member exactlythe member exactly
opposite to each other.opposite to each other.
• This is the most appropriate &This is the most appropriate & reliable methodreliable method
of testing to ascertain the quality / strength ofof testing to ascertain the quality / strength of
concrete.concrete.

11. DIRECT TRANSMISSION OF
PULSE ACROSS R.C BEAM

12. DIRECT TRANSMISSION OF
PULSE IN R.C COLUMN

13. INDIRECT TRANSMISSION :INDIRECT TRANSMISSION :
• Pulse velocity will be measured in concrete byPulse velocity will be measured in concrete by
placing transducers on theplacing transducers on the same planesame plane of members.of members.
• This is theThis is the least reliableleast reliable method of testing tomethod of testing to
ascertain the quality / strength of concrete. Thisascertain the quality / strength of concrete. This
method will bemethod will be adoptedadopted only when there is no otheronly when there is no other
option.option.

14. INDIRECT TRANSMISSION OF PULSE
IN R.C.DECK

15. SEMI-DIRECT TRANSMISSION :SEMI-DIRECT TRANSMISSION :
• Pulse velocity will be measured in concrete byPulse velocity will be measured in concrete by
placing transducers in planes perpendicular to eachplacing transducers in planes perpendicular to each
other.other.
• This is aThis is a moderately reliablemoderately reliable method of testing tomethod of testing to
ascertain the quality / strength of concrete.ascertain the quality / strength of concrete.

16. SEMI-DIRECT TRANSMISSION OF PULSE
IN R.C.DECK

17. Method of calculation of pulse velocity :
Velocity =Velocity = (Distance travelled / Path length)(Distance travelled / Path length)
Time takenTime taken
Pulse Velocity in concrete will be representedPulse Velocity in concrete will be represented
inin Km/secKm/sec..
AppropriateAppropriate correction factorscorrection factors to be appliedto be applied
depending on site condition & factorsdepending on site condition & factors
influencing velocity of pulse.influencing velocity of pulse.

18. Pulse VelocityPulse Velocity
(kM/sec)(kM/sec)
Concrete QualityConcrete Quality
Grading (as per IS:13311Grading (as per IS:13311
(Part-1)-1992)(Part-1)-1992)
Below 3.0Below 3.0 DoubtfulDoubtful
3.1 to 3.53.1 to 3.5 MediumMedium
3.5 to 4.53.5 to 4.5 GoodGood
Above 4.5Above 4.5 ExcellentExcellent
QUALITY GRADING CHART :QUALITY GRADING CHART :

19. FACTORS INFLUENCING THE VELOCITYFACTORS INFLUENCING THE VELOCITY
OF PULSE IN CONCRETE :OF PULSE IN CONCRETE :
• Type & content of cementType & content of cement
• Influence of reinforcementInfluence of reinforcement
• Use of admixturesUse of admixtures
• Type & size of aggregatesType & size of aggregates
• Homogeneity & density of concreteHomogeneity & density of concrete
• Age of concreteAge of concrete
• Presence of voids / cavities in concretePresence of voids / cavities in concrete
• Cracks in concreteCracks in concrete
• Curing of concrete, etc.,Curing of concrete, etc.,

20. • Measurement of concrete uniformityMeasurement of concrete uniformity
• Detection of cracking and honeycombingDetection of cracking and honeycombing
• Strength estimationStrength estimation
• Assessment of concrete deteriorationAssessment of concrete deterioration
• Measurement of layer thicknessMeasurement of layer thickness
• Measurement of elastic modulusMeasurement of elastic modulus
• Strength development monitoring.Strength development monitoring.
APPLICATIONS :APPLICATIONS :

21. 2. REBOUND HAMMER TEST :2. REBOUND HAMMER TEST :
• It is a quick method for assessing the quality ofIt is a quick method for assessing the quality of
concrete based on surface hardness indicated byconcrete based on surface hardness indicated by
the Rebound number.the Rebound number.
• An higher rebound value indicates the higherAn higher rebound value indicates the higher
strength / surface hardness of concrete.strength / surface hardness of concrete.
• This equipment works based on the springThis equipment works based on the spring
controlled hammer slides on a plunger within acontrolled hammer slides on a plunger within a
tubular housing.tubular housing.

22. Figure: Rebound HammerFigure: Rebound Hammer.
Weight < 2KgWeight < 2Kg
Impact Energy = 2.2NmImpact Energy = 2.2Nm
Suitability 20 – 60 MPaSuitability 20 – 60 MPa

23. Figure: Testing by Rebound Hammer

24. METHODS OF TESTING :METHODS OF TESTING :
Depending on the position of the rebound hammerDepending on the position of the rebound hammer
1.1. HorizontalHorizontal
2.2. Vertically upwardsVertically upwards
3.3. Vertically downwardsVertically downwards
4.4. Inclined vertical upwardsInclined vertical upwards
5.5. Inclined vertical downwardsInclined vertical downwards

25. POSITION OF REBOUND
HAMMER - VERTICAL UPWARDS

26. POSITION OF REBOUND HAMMER -POSITION OF REBOUND HAMMER -
VERTICAL DOWNWARDSVERTICAL DOWNWARDS

27. METHOD OF CALCULATION :METHOD OF CALCULATION :
•Average rebound number will be calculatedAverage rebound number will be calculated
after exclusion of freak values and applyingafter exclusion of freak values and applying
necessarynecessary correction factorcorrection factor for position offor position of
Rebound Hammer.Rebound Hammer.
•To evaluate the strength of concrete based onTo evaluate the strength of concrete based on
the rebound numbers, an appropriatethe rebound numbers, an appropriate calibrationcalibration
chartchart shall be established based on the laboratoryshall be established based on the laboratory
tests.tests.

29. FACTORS AFFECTING THE REBOUNDFACTORS AFFECTING THE REBOUND
HAMMER TESTHAMMER TEST RESULTS :RESULTS :
Mix characteristicsMix characteristics
(a) Cement type(a) Cement type
(b) Cement content(b) Cement content
(c) Coarse aggregate type.(c) Coarse aggregate type.
Member characteristicsMember characteristics
(a) Mass(a) Mass
(b) Compaction(b) Compaction
(c) Surface type(c) Surface type
(d) Rate of hardening and curing type(d) Rate of hardening and curing type

30. 3. COVER METER TEST :3. COVER METER TEST :
• Used for locating, mapping and thicknessUsed for locating, mapping and thickness
gauging of cover provided for embedded rebarsgauging of cover provided for embedded rebars
in concrete.in concrete.
• Equipment usedEquipment used ProfometerProfometer works onworks on
electromagnetic principles. The equipmentelectromagnetic principles. The equipment
consists of display unit coupled with probes ofconsists of display unit coupled with probes of
different types.different types.

31. ESTIMATION OF COVER AND MAPPING
OF REBARS IN ABUTMENT

32. ESTIMATION OF COVER AND
MAPPING OF REBARS IN BEAM

33. LIMITATIONS OF THE EQUIPMENT :LIMITATIONS OF THE EQUIPMENT :
• Only peripheral rebars can be detectedOnly peripheral rebars can be detected
• Second layer (if any) of rebar's cannot be detectedSecond layer (if any) of rebar's cannot be detected
• The accuracy of the diameter of rebar will varyThe accuracy of the diameter of rebar will vary
generally in the range of 10 to 20%generally in the range of 10 to 20%
• The actual numbers and position of rebars cannotThe actual numbers and position of rebars cannot
be located if the rebars are closely spaced in onebe located if the rebars are closely spaced in one
locationlocation

34. CONCLUSIONS :CONCLUSIONS :
1.1. There are number of tests such as Non-There are number of tests such as Non-
Destructive, Semi/Partial Destructive andDestructive, Semi/Partial Destructive and
Destructive tests that in practice to evaluateDestructive tests that in practice to evaluate
structural members.structural members.
2.2. Depending on data required, site conditions,Depending on data required, site conditions,
structural member conditions, etc., any one ofstructural member conditions, etc., any one of
them or combination of the above can be usedthem or combination of the above can be used
to ascertain the status of memberto ascertain the status of member

35. contd..contd..
33.. All these test procedures will give very goodAll these test procedures will give very good
information about the condition of the structuralinformation about the condition of the structural
members.members.
4. It is very important to achieve most accurate and4. It is very important to achieve most accurate and
reliable results, for which the person whoreliable results, for which the person who
operates the equipments should be technicallyoperates the equipments should be technically
sound and shall have good experience.sound and shall have good experience.

36. THANK YOUTHANK YOU