1 - Introduction to UPV - Dave Corbett

8/9/2019 1 - Introduction to UPV - Dave Corbett

1/42


2/42

Fundamentals o Wave

Propagation - Wavelength

pr eq

The wavelength o a sound wave is related to the velocity and the

frequency.

\

elf

where:

A = wavelength

c = sound velocity

f

=

requency

E.g. Concrete)

Velocity = 4000 m/s

Frequency = 54 kHz

Wavelength= 7.4 cm

Fundamentals

o

Wave

Propagation - Wavelength

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Wavelength is a limiting factor that controls the amount o information

that can be derived from the behavior

o

a wave.

It is very difficult to detect

n

object that is less than half the

wavelength.

So

in

real terms it means that objects smaller than half the

wavelength will be invisible.

E.g. Concrete)

Velocity = 4000 m/s

Frequency = 54 kHz

Wavelength = 7.4 cm

Y z

wavelength = 3.7 cm

7

cm

-

A small void e.g. 3 cm diameter is

invisible to the ultrasonic wave.

A larger void e.g. 5 cm diameter

can

be

detected.


3/42

Fundamentals o Wave

Propagation - Scattering

Fundamentals

o

Wave

Propagation - Scattering

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Inhomogeneities e.g. aggregate particles, voids) in concrete scatter the

signal.

The effect is very large if the size o the aggregate

s

equal to or larger

than the wavelength

o

the ultrasonic signal.

This influence can be significantly reduced by choosing a transducer

frequency, such that the wavelength is at least twice as large as the

aggregate size.

Ideally

Frequency x Aggregate Size


4/42

Fundamentals of Wave

Propagation - Summary

High Frequency

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Low

Frequency

Clearly defined onset - High resolution Onset Is less well defined - Low resolution

Short wavelength - subject

to

scattering Long wavelength - less subject

to

scattering

Attenuated rapidly - Short path lengths Less attenuation - Long path lengths

Max particle

size

7.5 mm Max particle size::: 75

mm

Smallest anomaly

that

can be

detected '

7.5

mm

Smallest anomaly that can be detected::: 75

mm

What

is

a short

path

length?

What is

a long path length?

Several dm Several m

Pundit Transducers

Max

. grain stze

Max

. grain size M

ax

. grain size

Max

. gr

ain

size

nmm

34mm '34mm

1

2mm

Min. lateral Min. lateral Min. lateral Min. lateral

dimensions154

dimensions dimensions

dimen

sio

ns

mm 69mm

69 mm

25 mm

Standard

ExPonmtlal

transducer

transducer

Concrete: ooarae

Concrete. wood

Concrete rough

Fine grained

aggregate. large

rock

surfaces, rounded

ma

terial only,

objects.

surfaces),

wood

refractory bricks,

rock heritage

rock(NXoorns)

sites)

Nooouplanl

250 kHz

Max. grain slze

:.7mm

Min . lateral

dimensions

15mm

Fine grained

material only,

refractory bricks,

rock

Small samples.

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500 kHz

Max

. grain size

3 m m

Min. lateral

dimensions

7mm

Fine grained

material only

refractory

bri ks

rock

Use on small

samples limtted

by

size

of

transducer

250 kHz

Shear wave

S-wave

transducer

Concrete, w

rock

Used for

detennlnatlon

of

E

modulus.

Requires special

oouplanl


5/42

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Reflections at Boundaries

As we saw in the explanation about scattering, sound travelling

through the concrete is reflected when it meets a boundary.

Concrete

d

material

The amount of energy that passes through the boundary and the

amount

of

energy that

is

reflected

is

determined by a simple equation.

R

=

Z2 -

Z

Z2 +

Z

R

is

the percentage

of

energy that

is

reflected.

Z

is

the acoustic impedance of the concrete

Z2 is the acoustic impedance

of

the second material

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Reflections at Boundaries

Acoustic impedance Z)

=density

of material p) x speed of sound in

the material v)

Material

Density Speed of sound

Acoust ic Impedance

ka/m

3

1 m/s

ka/m2x1os

Air

1.3 330 .000429

Concrete 2400 4000

9.6

Steel

7850 5920 46.5

Interface

Z

Z2

R

=Z2-Z1

Z2 Z1

Concrete/

9.6 .000429 99

Air

I

W

Concrete

9.6 46.5

66

Steel

I W +

Concrete

9.6

26.8

47

Granite

I

W


6/42

praceq

Wave Types

There are several modes

o

propagation o sound waves in solids

The two types we are concerned with are:

Longitudinal or compression waves (also called P-waves)

Transverse or shear waves (also called S-waves)

time

=

200.07 us

longitudinal wave

shear wave

0.8

0.6 Rayleigh wave

I

N 0.4

.2

0

0 0.5 1.5 2 2.5

3

x(m]

Shde 1.1 l 201.1 Procq ',

Wave propogation

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in a homogenous material

Situation 1:

Homogeneous block

Size: 1m x 3m

vL=

5000 m/s

v

5

= 600 m/s

p

= 200 kg/m

3

Transmitter:

Diamter. 50 mm

Position: x = .5 m, z = m

Receiver:

Diamter. 50 mm

Position: x =1.5 m , z =1 m

0 5

.. O

.

.

\

bnWJOU w

4

600

.......,

1000

0.1

0.00

0.00

0.04

0.02

0

0 .02

0

.

04

0

.CE

0. ll

0.1


7/42

Real situation

time=

200.07

us

Wave propagation

in an inhomogenous material

Situation 2:

Inhomogeneous concrete

block

Size: 1m x 3m

vL

=

000 m/s

v

5

=

600 m/s

p

=

200 kg/m3

ggreg te

:

Size: S 32 mm

Disllibution: random

Number: 4000

'

.

h :Ml

.t u

I

L

( ' '

20C

YMlio

pr eq

pr eq

0.04

0.02

0

-

-

-0.02

-0.04

'

. .


8/42

NOT of oncrete using

Ultrasonic Pulse Velocity

Methods

Ultrasonic Testing o Concrete

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The ultrasonic pulse velocity o sound in a material depends on its

density and its elastic properties, which

in

turn are related to the quality

and the compressive strength o the material.

It is therefore possible to obtain information about the properties o

concrete structures by ultrasonic investigations:

Uniformity

o

the concrete

Cavities , cracks, defects due to fire and frost

Thickness of structure

Modulus o elasticity

Compressive strength

Shde 16

l

201


9/42

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Standards

EN 12504-4 Determination of ultrasonic pulse velocity

ASTM C597-02 Standard test method for pulse velocity through concrete

BS 1881 Part 203 Recommendations for measurement of velocity of ultrasonic

pulses in concrete

1501920-7:2004 Non-destructive tests on hardened

concrete

determination of

ultrasonic pulse velocity

5 33

Part 1 Non-destructive testing of concrete - ultrasonic pulse velocity

(India)

CECS21 Technical specification for inspection of concrete defects by ultrasonic

method (China)

ASTM 02845 Standard Test Method for Laboratory Determination of Pulse

Velocities and Ultrasonic Elastic Constants of Rock

Pundit nst uments comply with all

o

these standards

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Pulse Velocity Determination

~ h l ~

18 2014 r ~ s q

Direct

Transmission: Optimum configuration.

Maximum signal level. Most accurate method

of

pulse velocity determination. Path length is

measured from centre to centre

of

the transducers.

Indirect Transmission: Signal level is only about

2 - 3

of

signal level when using direct

transmission. Path length is uncertain. Use the

surface velocity mode or line scan to eliminate

this uncertainty. Pulse velocity determined by this

method may

be

lower than that from direct

method by 5 -20 . Where possible carry out a

comparison measurement to determine this.

Semi direct Transmission: Sensitivity is

somewhere between the other two methods. Lower

accuracy than the direct method. Path length is

measured from centre to centre

of

the transducers.


10/42


11/42

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Tools to locate the trigger point

Zoom

button

Touchsceen ope. >tion

ollow Trigger function

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ursor Triggering modes

Automatic Triggering Manual Triggering

Dual cursor Amplitude marker


12/42

Amplitude trigger

When set

the

user

may

manually

set the level at

which

triggering takes place by dragging the cursor on

the y-axis .

Measurement modes - Menu

f

1

1 ,

6

t .. ..rarsm ss1or . . v ,

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Basic Modes

t o

Transm

ission Time

Distance

Special Modes

t: Crack Depd

E

E-Modulus

Multi-Measurements

I =

UneScan

Eli

Area Scan

; I

Pulse

Velocity

il surface Velocity

9 Data Logg i

ng

Compr . Strength

........ - -

-- -


13/42

Pundit PL-200

Basic measurement modes

Distance

Input Required

Pulse velocity

Output

Transmission time

Distance between the two

transducers

Surface Velocity BS 1881 :203

5

1 2 3 4 5

Dist n e mm

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Pulse Velocity

Input Required

Distance between the two transducers .

Output

Transmission time

Pulse velocity

600

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The exact length of the

transmission path is uncertain due

to the significant size of the area of

contact between the transducer and

the concrete

The uncertainty is eliminated by

making a series of measurements.

The transmitter remains t the

same position for the entire

measurement.

The receiver is moved a fixed

increment b along a line.

The transmission times are plotted

on a graph against the distance.

A best fit straight line is drawn

through the points.

The slope

of

this line is the mean

pulse velocity.


14/42

Pundit PL-200

Measurement mode - surface velocity

In-Situ Compressive

Strength Estimation

pro eq

The transmitter remains

in a

fixed posi

tion

.

The rece

i

ver

is moved

at

a

fixed

interval

.

A best fit line is

drawn

through the

points

generated

.

The slope of this line is the

mean pulse

velocity.

e g 305mm/100s = 3 05

pro eq

Ultrasonic Pulse

Ve

locity tests are used

in

parallel with compression tests

to obtain a correlation to compressive strength .

This procedure is recognized

in

most major standards e.g.

N

13791 and

ACI 228.1R.

This method can also be used in combination with rebound hammer

measurements for an improved estimation. This is the method known as

SONREB.


15/42

Measurement mode

Compressive strength

Modulus of lasticity

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nput Required

Distance between transducers

Rebound value X

either R-value or Q-value)

SONREB curve defined in PL

Link software)

Output

Transmission time

Compressive strength.

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16/42

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STM 2845 Modulus of Elasticity

Ultrason ics is used in geology

to determine

the elastic properties

or

rocks and minerals. The application is described in

the

ASHA

standard D 2845

ASTM

D 2845 -

Standard Test

Method

for

laboratory Determ i

nation

of Pulse Velocities

and

Ultrasonic Elastic

Constants

of

Rock

Determ

ines

the

pulse velocities of

compression P) waves

and shear

S) waves in rock from

which the

dynam

ic

elastic

constants are

calculated.

, The ultrasonic evaluation of rock properties is useful for preliminary prediction of static properties. The test

method is useful for evaluating the effects

of

uniaxial stress and water saturation on pulse velocity. These

propert

ie

s are

in

turn useful

in

engineering design

.

,

Recommendations are given

for sa

mple

prepara

tion and

sample dimensions.

calculations

,

Having

measured

the

compress ion and shear velocities, the stand

ard prov

i

des the

formulas for :-

E = Youngs'

modulus of

elasticity

G =

modulus

of

rig

idity

or

shear

modulus

,

=

Poisson

's rat io

A = Lame 's constant

K =

bu

lk modu lus

(

Note

For some of these calculations, e.g modulus of elasticity, it is a

ls

o necessary

to

know the den

si

ty of the

material.

Slide

31

O ;Jqi 4 Procoq

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STM 2845 Calculations

E = fpV / 3V/ - ./V/

J

V/ - V/)

where:

p

Young modulu o ela ticity. p i (or Pa). and

= den i

ry

. lb in.

3

(or kg

3

) :

G =

p

/

where:

G = modulu o

ri

gidi

ty

or shear modulu , p (or Pa):

= -

JI

/ ) fJCV/ - v ]

where:

= Poi son ra

ti

o:


17/42

P-wave

TX

pro eq

r:t

. ;.1:

~ ~

'\

Jr' . . .

:

:

......

..

. ~ : . : ' 1 9 4 ' . : .

..

-

;c..:.,;

; . : : ~ .

.

. , ~ , . : . ~ 1 ; - ~ . ~ - ' ' ; :: r :

~ : ~ - : ~ : ' / i : } ; / J

: [ ~ : : l

.i ~ . I ...

:,

~ ..

~

.. eP. .. ~ ~

. .

.

,

. .t i ' - J t : : ~ - . ~ - - - .. ~ ..

,...

. ~ ~ < t : .::e._,.

~

- 1

..

:.; .

:

1 ' - ' . \ . 7 ~ 1 t .. : J I . ~

' \ . ~

1:-

'

... .)a . . . . . . ... . : r . . - ~ . - ..

.

... ~ l .. . -uo

....

~

:. .

t: i: .. I ..

. r-;

.

.

:

..-e. 1 .. ~ 11

...... ll

I

c:201 t. OlrlR:.eM I

RX

Longitudinal P) Waves

In

a longitudinal wave the particle displacement is parallel to the direction

of

wave propagation. The

animation shows a one-dimensional longitudinal plane wave propagating down a tube. The particles do not

move down the tube with the wave; they simply oscillate back and forth about their individual equilibrium

positions. Pick a single particle and watch its motion. The wave is seen as the motion of the compressed

region (ie, it is a pressure wave), which moves from left to right.

pro eq

S-wave

Transverse or Shear S) Waves

In

a shear wave the particle displacement is perpendicular to the direction

of

wave propagation. The

animation below shows a one-dimensional transverse plane wave propagating from left to right. The

particles do not move along with the wave ; they simply oscillate up and down about their individual

equilibrium positions as the wave passes by. Pick a single particle and watch its motion.


18/42

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P- and S- Wave Properties

P-waves travel significantly faster than S-waves.

54 kHz P-Wave Concrete)

Typical velocity

=

4000 m/s

Wavelength \ 7.4 cm

54 kHz S-Wave Concrete)

Typical velocity 2500 m/s

Wavelength

\

4.6 cm

Pwave

S-wave

Pundit Lab Pundit PL-200

Measuring with S-wave Transducers

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Pundit Lab

Shear wave coupl ing gel

When measurements with the 250 kHz shear wave transducers are

performed, it is cruci lto use the special shear wave coupling paste,

otherwise shear waves cannot be properly transmitted into the object

under test. The 250 kHz shear wave transducers supplied by Proceq

Part No. 325 40 049) come supplied with the correct coupling paste .


19/42

Pundit Lab

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Measuring with S-wave Transducers

-

-

=

..

A waveform display MUST be used to manually locate the onset

of

the shear wave

echo, as it is always preceded by a relatively weak longitudinal echo wh ich is picked

up by the automatic triggering.

For Pundit Lab, this means that this can only be done when connected to a

PC

S-wave detection

pr eq

Correct measurement procedure

)

Misaligned by

9

-.

o

eakS-wave

I

.....

component

J

u

l

J

Correctly aligned

.

Strong S-wave

_... ....

__

component

-

.

- ...

..

-

As we have seen, shear waves travel in a one-dimensional plane. The strongest

signal appears when the transducers are correctly aligned.

This property can be used to correctly detect the shear wave component

of

the

received signal.

Rotate one transducer into and out of alignment and watch the S-wave

component increase and decrease.


20/42

PunditLink Calculator

E-Modulus and Poisson s Ratio

Pundit Link is equipped with a calculator for both.

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Simply enter the measured transmission times made with the P-wave and S

wave transducers.

CMcutate

oinon

s

Ratio

Modulus

MP

Pundit PL-200

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Measurement Mode: E-Modulus

Implemented directly on the instrument.

Measure either with P- and S-wave transducers separately or

with S-wave transducers only.


21/42

E-Modulus

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Separate P- S-wave measurements

Can begin with either the P or the S-wave transducer but the first

measurement should be made with whichever is indicated in the top right

hand om r.

In this case it is a 54 kHz P-wave transducer.

E-Modulus

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Measure the P-wave transmission time. Note the manual triggering must be

used in this mode. Automatic triggering is deactivated.

Press on the

PS icon.


22/42

E-Modulus

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f -

Connected Transducer

G SOkHz

Pulse

Echo Shear

Wave

Trans

G

24

kHz

Proceq

Transducer

G

54 kHz Proceq

Transducer

G

54 kHz Proceq

Transducer Exponential

G

150

kHz

Proceq

Transducer

G

250

kHz Proceq Transducer

G

250

kHz

Proceq

Transducer

s i - r

Wave

G 500 kHz Procea Transducer

Select the S-wave Transducer.

E-Modulus

0

0

0

-

0

0

)

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Separate P-

S-wave measurements

Measure the S-wave transmission

time

Verify position by rotating one

transducer 90. Here we can

clearly see that the S-wave

component has disappeared

completely.

The E-modulus is calculated automatically from the two

transmission times and the density input.

On PL-Link, Poisson's ratio is also displayed as a result.


23/42

E-Modulus

pro eq

Using only an S-wave transducer

When measuring with the S-wave transducer, it is only necessary to

o

a

single measurement. Use the dual cursor to mark the locations of the P-wave

and the S-wave and the E-modulus is calculated automatically.

pro eq

PL-Link Software E-modulus

20

40 60 80

JOO

120 140 160 180 200 220 240 260 280 300 320 340 360

Manual trigger points may

be

retroactively adjusted.

All settings that are coloured blue may be adjusted,

e.g. distance between probes, density, unit.

Comments may be added to the file .

TimeWSJ

Settings

Ruults

Devitt lnfOfmation

Distance: 4 m

OeV lceNamt:

O..Srty.

3000kg.:m]

N u m b t t

Po

1s.son sRatio:

l.2549 Sottwe Versi

E ModuJus:

S9.20 GP

Hardware RtvtSK>f'l

w

TirM{JJs}

Ve1ty (m/S)

T y p e

Probe Freq. QcHz)

P r ~ G a m x }

Pulse-

Voltage (V)

Ca lib. ~ Offset (s )

Comment

:Add]

81.8

4889

Shear

Wave

250

100

15

-0.6

142.6

2804

h e W ~

250

100

15

-0.6

....

UPOl

9 993

1.1.1

83


24/42

Dynamic and Static

Modulus o Elasticity

Empirical relationship between static and

dynamic modulus o elasticity and the pulse

velocity

Pulse Modulus

o

Elasticity MN/m

2

velocity

Dynamic*

Static

km/s

3.6

24'000 13'000

3.8 26'000 15'000

4

0

29'000 18'000

4.2 32'000 22'000

4.4 36'000 27'000

4.6

42'000

34'000

4.8

49'000 43'000

5.0

58'000 52'000

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6o

,o

0

0

ao

10

0

o

o

This is the parameter that is determined using ultrasonic pulse velocity

measurements with P S-wave transducers .

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Uniformity of oncrete


25/42

Uniformity Testing

Concrete Classification

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The Indian standard IS13311 provides a guideline for estimating

concrete quality.

Similar to rebound hammer testing. Many measurements are made on

the structure.

A statistical analysis is carried out and then the concrete is classified

according to the table below.

A similar method

is

also described

in

the Chinese standard .

Pulse Velocity Concrete

Quality

Grading

>

4500 m/s

Excellent

3500 - 4500 m/s

Good

3000 - 3500 m/s Medium


26/42

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Effect of coarse aggregate content

ACI MATERIALS JOURNAL TECHNICAL PAPER

Tiile

no

. 104 M38

Investigation

of

Pulse Velocity-Strength Relationship

of

Hardened Concrete

fn.700 = .00.WO x exp(0 .002 10 x u

fc(l OOl

= 0.0029

1

x exp(0.002 1 x u )

fc


27/42

Pundit

PL-200 scanning modes

Measurement mode - line scan

Pundit PL-200 scanning modes

Measurement mode - rea Scan

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The horizontal grid settinga

remains constant. but the

distance between the probes x

can be changed for each

measurement according to the

object shape.

The current A-scan is shown in

the top half of the screen. The

grid is shown in the lower half.

Previous A-scans can also be

viewed by tapping on the

corresponding point in the lower

window.

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Even more useful is the Area Scan, a

2

visualization based on a user

definable grid and a user definable colour scale.

n

this example the

max and min have been set to the limits defined in the Indian standard .

S i d A ~ 2 0 1 4

r ~

\


28/42

rackDepth Determination

Measurement mode rack depth

Note:

Crack depth method

according to BS 1881 .

Part 203 method with Just

two measurements.

Measure at an interval 'b'

and '2b from the centre

of

the crack.

The

crack depth is

calculated automatically

using simply geometry.

For this method to give good results, the crack must e

perpendicular to the surface. It must also e free of water or debris

which would allow the wave to propagate through the crack. The

crack must e sufficiently wide to prevent the wave from simply

propagating around it. There must also e no rebars within the

vicinity of the crack. f any of these conditions occur. the result will

e severely affected and it may appear that the crack depth is much

smaller than is actually the case.

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29/42

Crack Depth Determination

BS Method

The British standards method is a method

recommended by 884408, and the method

of

calculating the crack depth by arranging

oscillator and receiver from the crack at equal

intervals at transmission time t2 of

X2=300mm and transmission time

t1

of

X1=150mm.

2 2

d

=

150 4tl

t

t

2 t 2

2 1

T : distance from crack

to

surface of oscfllator mm) . R : distance

from crack to surface of

receiver mm) . V : Sound speed

n

health

p rt by

surface scanning method

t

each intervals

of

between

oscfllator nd receiver kmls) . I : transmission time of crack posffion

s)

Slu:le

57 e 2014Proceq


Tc - To Method

In

the Tc-To method, the transmission time is

measured by arranging longitudinal wave oscillator

and receiver at intervals 2a on the surface

of

the

healthy part

of

the examination body. Next, the

transmission time is measured by arranging

oscillator and receiver at intervals 2a so that the

crack may become a center. The crack depth is

obtained from the next equation.

d : depth of crack (mm).

2a

: distance between oscillator and

receiver (mm , tc : transmission time of crack position (s) . to :

transmissi

on

time on surface of health part (s)

$hda 8 C 2014 Proceq

pr ceq

pr ceq

T

r i

a

... . ....

T

r

.

I

.

o

l i t TrTi Mfhoi.ll Ll h


30/42


T - To Method

T method is a method of requesting

discontinuous time T at the crack position

from the curve relation between the

transmission distance and the transmissior

time) at the run of the fixation

of

oscillator

and the movement of receiver at constant

intervals, and calculating the crack depth

from the following equation.

d T t

T cot a +2L

1

= CO

T cot

a

L

1

)


Delta Method

The delta method is fundamentally the same

as the

Tc To

method, and method of

measuring the transmission time by placing

the crack and arranging oscillator and

receiver, and obtaining the crack depth from

the next equation.

d

- T -

{

T _9 +W

t }2

2V

T

T : distance from crack t surface of oscillator mm) . R : distance

from crack to surface of receiver mm) . V : Sound speed in health

p rt

by

surface scanning method at each intervals of between

oscillator

nd

receiver {kmls) . t : transmission time of crack position

s)

hde60 0 2014P1ocaq

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11\t. 3

Delta

lllthod


31/42

Crack Depth

Determination Sloped Crack

You

are in engineer at a testing lab.

Your project manager has just asked

you to determine the depth o crack

as shown. What do you do?

5 ~ 6 2 14Proceq

Crack Depth

Determination Sloped Crack

How to determine Orientation o

Crack?

Does the crack travel straight down?

Does the crack slope to one side?

Which side?

How to ensure your results are

accurate?

Skde l i2 0 2014 Proc aq

p r e q

pr eq


32/42

Crack

Depth

pr eq

Determination

Sloped Crack

Oblique

Crack

Depth -

S

1881 Part 203

pr eq

2.5b

Determine whether or not the crack Is oblique to the surface.

Position both transducers close to the crack. Tx, Rx . Measure the

transmission time.

Move the receiver to position

Rx2

Measure the transmission time.

If the crack were perpendicular to the surface you would expect the

transmission time to increase.

If the transmission time decreases, it indicates that the crack is slanting

towards the receiver as shown.

Transmitter Is placed at a distance

of

2.5b from the

centre of the crack.

Measure the transmission times:

T

1

at b, T

2

at 2b and T

3

at 3b.

Depth

of

the crack Is given by the formula.

Crack

Depth

v

T { \ ~ T r 2s]


33/42

Crack Depth

Determination - Sloped Crack

Take multiple readings

perpendicular to the orientation

o crack.

Report min max and average

depth o crack.

Slrdl 65

e

2014 Proceq

Understanding Cracks

Cracks depths are not typically

uniform throughout the length

o

the crack.

Surface

Crack Depth Profile

ShdPf 6 C 2014

Procaq

pro eq

pro eq

Increasing

Depth

Points

o

Measurement


34/42

Understanding racks

rack measurements can be

affected by foreign particles

Surface

rack Depth Profile

Understanding racks

rack measurements can be

affected by foreign particles

pro eq

Increasing

Depth

Points of Measurement

pro eq

r - ' ' ' ' . ' ' ~ 1 1 1 1 1 1 - - ~ -

Surface

rack Depth Profile

Increasing

Depth

Points of Measurement


35/42

pr eq

Working with SONRE

pr eq

SONREB Method - 1

SONREB comes from the words SONic REBound .

Both ultrasonic pulse velocity and rebound hammer measurements can

be

correlated to compressive strength. e.g. EN 13791 ).

The SONREB method is a method of combining an ultrasonic pulse

velocity measurement with a rebound hammer measurement to

improve

the accuracy

of compressive strength estimation.

The format of the curve

is

:

Compressive Strength fck

=

.Vb. c

Where: a, b and c are constants

Vis

the ultrasonic pulse velocity

in

m/s.

S

is

the rebound value.

Shde

7

2014

r o c ~


36/42

pr ceq

SONREB Method - 2

This example taken from a real set of data illustrates the kind of

improvement

in

strength estimate that can be expected.

80

Compressive Strength

70 .--

1DJIO,....,_.

FOJ'OQ .-

.. t

.

.

.

. .

60

e 3

0

10

0

..

,

w

r 3 . , , s r

Schmidt H mmer . Q . Vfue

Correlation using only UPV values.

Correlation coefficient 0.7

Correlation using only rebound hammer values.

Correlation coefficient 0.79

The SONREB function for the same set

of

data gave:

fck

=

.314x1011 \f2.8096 S0 8602

with a

correlation coefficient of

0.88.

Shde

71 C20 14

Pu

>e

aq

pr ceq

SONREB Method - 3

The user has three options for working with SONREB curves.

Option

1 - Create your own SONREB curve for the concrete under

test by using your own test data. This method provides the best results

but is not alwfls possible practically.

V

Decreasing reliability

Option

2 -

Find a best fit for your concrete by using existing SONREB

curves and comparing with cores taken from the site . This is the next best

method and is the most practical method for obtaining reasonable results.

Decreasing reliability

Option 3 - Simply use an existing SONREB curve. This method should

only be used if

it is

not possible to take any cores.

In

this case the user

should ideally select a curve that was created using similar concrete to

the concrete under test.

Shcle

7

. )

2014

P1ocug .


37/42

SONREB Method - Option 1

For each cylinder make a rebound hammer

measurement and an ultrasonic pulse

velocity measurement.

Then crush the cube in the press to obtain

the compressive strength.

This provides one data point.

Pundit lab SllverSchmldt

Ultrasonic

Compressive Pulse

Strencth f I

Velocity {V) Q value

S)

29.5 4237

36


pr ceq

pr ceq

Pundit

Lob+

Ult,..onk

Corn,,,.W.

PulN

SlverSchmidt

When you have sufficient data points you can calculate

the SONREB curve.

Stronrd>fu

Velocttv(V)

Q-value S)

29.5

42l7

36

32.6

4608 38

40.3

4484

45

41.2 4630

42

44.2 4587 49

45.3

4673 56

48.5

4644

49

50.6

4695

47

51 .5

50

52

4760

56

55.8

4744

57

57

n 2

53

58

.1

n 8

57

60.9

4673

66

62.3

4732

54

68.6

4854 61

In this example, 16 cubes were used.

The SONREB coefficients can be determined using an

array function in EXCEL called LINEST .

0ptr.tirJg

Udclnl

Purdl

l

R.-.

(JICI

170t.b)

~ ~ P I J l d l l l l t P t m

CPdl:11Mb

S..Ar f \JJ lel l l . IO(Plul ; - .631)

lpdf lAOICb)

P\lfd LIO 5rfur Ddr

213

,

COftCNtltFi. l4111b

f ' U l d l d ; S t l l O ' w ' l l l ~

g _

An EXCEL Macro for carrying doing

this automatically is available for

download from the Proceq website

and is also supplied with the product

documentation.

The document is called:

Sonreb_Method_Macro_v_1_04_E


38/42

Sonreb Method Macro v 1

04

E

- - -

-

TABLE : Rew Data for the Sonreb Method

Compressive

Pundit Lob+

S1lvcr../Or1g1nal

Strength fck Ultrasonic Schmidt

(MPaorPSI) Pulse Velocity Rebound-

(V)

(m

/s or fUs) Values (SI

Sample 1 29 .5

4237

36

Samele

2

32

.6 4608

38

Sample 3

40 .3 4484

45

Sample4

41.2 4630 42

Samele 5 44.2 4587 49

Sample6

45 .3 4673

56

Samele 7

48

.5

4644 49

Samele 8

50

.6

4695

47

Sample 9

51.5

4717

50

Samele

10 52

4760

56

Sample 11

55.8

4744 57

Sample 12 57

4722

53

Samele

13

58

.1

4728

57

Sample 14

60

.9

4673 66

Sample 15

62

.3 4732

54

Samole

16

68

.6 4854

61

Sample 17

Samele 18

-

' ..

Sonreb Method Macro v 1 04 E

- -

- - -

9.

59431E

11

2.786113142

0.873583548

0.88 154857

pr ceq

Stop

1:

Select up to twenty (20

)

test

points from diff

eren

t areas that

you

want

to

Include

In the

Sonreb

calculation. (

minimum

of

rive

(5) test

points

required

,

may

al

so be

used on

standard cubes or cylinders )

Step 2:

Obtain Pundit Lab Velocities

and SilverSchmldl

Q

Values (or

Orlg

l

nol

Schmidt) readings at these

points

(

note

that the

SilVerSchmldl

reading

can

be an av

erage

of

ten

read

ings

aro und the same area

.)

Stop 3: Exlrect

concrete core

samples

from the

selected

test

areas

. The

concrete cores should not have

an

y

reinforcing bars with in the core .

Step 4: Perform compress ive strength

test method

on the cores

under

simllor

field conditions .

Stop 5: Input the obtained

Compressive

Strength,

Pundit Lab

Ultrasonic Pulse Velocities and

the

SilverSchmidt Q-VelUes

(or

R-Velues

)

into

Table

1.

Input

et

least

live

rows

of

data .

pr ceq

Step 7: Once you have the constants,

you can

ei

ther input the constants into

the

Pundit

Lab

via

Pundit

Link

Software

or use

Sheet Obtain

Comp

.

Strength,

wh

ereyou have

to

manually

i

nput

the

pulse

v

elocity

reading

(V)

and

the read

ing from

the

Si

erSchmidt

(Q)

(

or Original

Schmidt - RValue) t

obtain

the

compressive

strength

at that

test

point


39/42


IOdlwKttBrMllnun

' 1. a...i. _ttrr

.)

-

-

-

. o oooooooooona

UNlll1420000

e a

0.11l514IOOOO

1 :... ,,..

Shde 7 C 20141 Proceq

100


pro eq

'

1

pro eq

There are many studies on the SONREB method to be found in the

internet. The table below shows examples

of

the curves defined in some

of those studies. All are based on Original Schmidt R value.

Correlation

Author

f

ck

=

7.876-101 9y4 .636 s 1.141

Lenzi, Versari , Zambrini 2010)

f

ck

=

7.695-10-

11

V2

6

S

1

.4 RILEM-NDT4

1993)

f

ck

=

1.2

10

-9

IJ2

.446

s 1.o

sa

Di

Leo

e

Pascale 1994)

f

ck

=1.

51

10

1 yo

.

ao84

s1 .aa15

Masi 2005)

fck

=

8.06-108 y 1

a

s S1.246

Gasparik

1992)

f

ck

=0.0056 y

1.439

s1 .1s9

CECS21 standard rounded

aggregate particles) (Note V in km/s)

f

ck

=

0.0162 y1 .sss s 1.410

CECS21

standard

crushed

aggregate particles) (Note V in km/s)

Slide

78

0 2014 Proc.uq


40/42

proceq


In many cases it is simply not practical to create a curve for

the concrete under test due to cost, or in the case when

testing is being carried out on an existing structure.

This method assumes that it is possible to take a small

number of cores from the structure for compressive strength

testing.

Obtain a rebound value at the same location as the core will

be extracted.

Make an ultrasonic pulse velocity measurement at the

location where the core will be extracted.

Take the core and crush it in the press to obtain the

compressive strength reading.

This provides one data point.

In this example four cores have been used.

Rebound testing and pulse velocity measurements can be

made at many locations.

Sla'.le

Cl l

11 Proceq

....

--

2

3

7

I

n

Noofcort

4

UPY

-

c

IYI

-

-

51

-

'

-

,,

...

-

...

-

.,

-

,.

-

-

-

Vl

-

-

-

proceq


This method uses the RILEM (1993) recommended method and makes use

of

previously

derived SONREB reference curves.

SONREB values are calculated from the data points available using selected reference

curves.

Least squares analysis is used to determine which curve provides the best fit.

A correction factor is applied to the reference curve based on the results of the least

squares I t th b t fit

bi

h d

1

bi

na ys1s ogive

e

es poss1

e

tot

e

ata ava1 a

1e .

Noa f -

llULEM NOH

19931 . . . . . - -DI

Loo o ~ c l o

4

fct; 1.mx o uV s

1. c 1.2x10V-1 - /

,

..

.. .

-

...

- --

....

........ R...C.

........

..........

-

,

181

-1

....,.

...

.

---.a.

-

UI

-

2 ....

. ..

...

'

.....

'

....

'

-

O>

...

...

'

-

,,.

n

M

.

-

'

.. lW

...

,

.

.,

.,,

U l

.

-

U5 ....

...

-

'

I

'

.

'

-

.

'

...

...

-

.,

.,

'

H

.,

... ...

'

-

,

...

'

..

.

-

'

H u

''

.

.

'

'

..

, ......... .

c,

I

,.

I

c,

I

I

_ [

---

S. . .16

. . )1

._.,.,..._

.......

I

n

ShdeBO CJ 2014 P1ooeq

......___.....


41/42

SONREB Method - Pundit Lab+

1ida61

? 4 f ~ o c e q : : :

SONREB Method - Pundit Lab+

B i

I c I

..

;L

J

- -= ::

[J

EJ[ ]

B CJ

[J

~ .

r::J

OsonReb_Gas 89 8 [: :J

B r

pro eq

Perform the rebound hammer

test and record the rebound

value.

Note. Pundit Lab+ allows

either a

Q

value or an R value

to be used

in

conjunction with

a SONREB formula. It is up to

the user to define the curve

wi

th

whichever type

o

hammer is to be used.

pro eq

In the System Settings on the

Pundit Lab+ select the

SONREB curve.

If a SONREB curve is

selected the rebound hammer

symbol appears in the lower

right hand corner

o

the

screen.

Click on this symbol to enter

the rebound value determined

in the previous step.


42/42

SONREB Method - Pundit Lab

l : f\P

42 3

S

~ V ]

-

~ M ~ ~

00

Questions

pr ceq

Perform the pulse velocity

measurement.

Once the measurement has

been made, clicking on the up

arrow of the navigation key

switches the display between

pulse velocity and

compressive strength.

pr ceq

Documents

1 - Introduction to UPV - Dave Corbett