proceq seminar 05 2013 covermeter upv and sonreb malcom lim

5/24/2018 Proceq Seminar 05 2013 Covermeter UPV and Sonreb Malcom Lim

1/104

Proceq

Concrete Testing

Rebar DetectionCover Meter

Malcolm Lim General

Manager ProceqTechnical Services

May 5, 2013


2/104

2

What is Concrete?

Portland Cement - The cement and water form a paste that coats the aggregate

and sand in the mix. The paste hardens and binds the aggregates and sand

together.

Water- Water is needed to chemically react with the cement (hydration) and too

provide workability with the concrete. The amount of water in the mix in poundscompared with the amount of cement is called the water/cement ratio. The lower

the w/c ratio, the stronger the concrete. (higher strength, less permeability)

Aggregates-Sand is the fine aggregate. Gravel or crushed stone is the coarse

aggregate in most mixes.

http://www.youtube.com/watch?v=MQx5r1kJq5E
http://www.youtube.com/watch?v=MQx5r1kJq5Ehttp://www.youtube.com/watch?v=MQx5r1kJq5E


3/104

3

Basic Desired Properties

The concrete mix is workable. It can be placed and consolidated

properly by workers or equipment.

Desired qualities of the hardened concrete are met: for example,

resistance to freezing and thawing and deicing chemicals, water tightness

(low permeability) , wear resistance, and strength. Know what you aretrying to achieve with the concrete.

Economy. Since the quality depends mainly on the water to cement

ratio, the water requirement should be minimized to reduce the cement

requirement (and thus reduce the cost).


4/104

4

Concrete Admixtures

Accelerating admixture- accelerators are added to concrete to reduce setting

time of the concrete and to accelerate early strength. Calcium chloride is a lowcost accelerator, but specifications often call for a non-chloride accelerator to

prevent corrosion of reinforcing steel.

Retarding admixtures-Are often used in hot weather conditions to delay setting

time. They are also used to delay set of more difficult jobs or for special finishing

operations like exposing aggregate. Many retarders also act as a water reducer.

Fly Ash- Is a by product of coal burning plants. Fly ash can replace 15%-30% of

the cement in the mix. Cement and fly ash together in the same mix make up

the total cementious material.

Fly ash improves workability

Fly ash is easier to finish

Fly ash reduces the heat generated by the concrete


5/104

5

Reinforced Concrete

Although concrete is an excellent building material and is extremely strong in

compression, it has one limitation concrete is weak in tension. By combining

concrete with a material that is strong in tension, a structural element can be

created that can resist tension, moment (bending forces) and shear, as well ascompression


6/104

6

Steel Reinforced Concrete

The most common composite is steel-reinforced concrete, which utilizes steel

reinforcing bar, otherwise known as rebar, embedded in poured concrete.

Rebars most basic function is to resist the tension at the bottom of a beam or

slab that is subject to bending.


7/104

7

Wire Mesh Reinforced Concrete

Another type of steel reinforcement used in concrete is welded wire mesh

(WWM) or welded wire fabric (WWF). This type of reinforcement consists of

pieces of wire or rebar welded together to form a grid pattern. The size of the

grid pattern is typically 4-inch-by-4-inch up to 8-inch-by-8-inch. This type of

reinforcement is used to minimize shrinkage cracking in the surface of the

concrete.


8/104

8

Prestressed Concrete

Pre-tensioned concrete is manufactured with steel cables or bars, called

tendons, that have been pulled taut before the concrete is cast into shapes.

The steel, even when the member is not loaded, is pulling the concrete

together. Pre-tensioned concrete is manufactured in many of the same shapes

as pre-cast, reinforced concrete.

Post-tensioned concreteachieves the same result by running steel tendons

through specially designed ducts in the concrete member, then pulling them taut

and fastening them in the field. Post-tensioned concrete is most commonly used

in large building projects such as high-rises and bridges. Post-tensioned

concrete slabs-on-grade also can be found where there are unusual soil

conditions.


9/104

9

Precast Concrete

Precast concrete is typically manufactured in a shop and delivered, ready to

use, to the building site. Steel bars or mesh are often embedded where tensile

forces are expected.

Typical examples of precast concrete include beams, panels and pipe.
http://images.google.com/imgres?imgurl=http://www.prestasi-concrete.com/images/T%20beam%202.jpg&imgrefurl=http://www.prestasi-concrete.com/product%20range.htm&usg=__a_dOQfp150MRiGSno4SQAaBDS8k=&h=1118&w=950&sz=364&hl=en&start=1&tbnid=qnZFBqMFKRlkbM:&tbnh=150&tbnw=127&prev=/images?q=precast+concrete+beams&gbv=2&hl=enhttp://images.google.com/imgres?imgurl=http://www.shermandixie.com/products/pipe/pipe1.jpg&imgrefurl=http://www.shermandixie.com/products/pipe/index.php&usg=__fxlnHHuQCU2OSeNtk7kDsb6jRFc=&h=185&w=225&sz=12&hl=en&start=2&tbnid=QipmjqlRD5eDYM:&tbnh=89&tbnw=108&prev=/images?q=precast+concrete+pipe&gbv=2&hl=enhttp://www.osh.govt.nz/publications/series/ia26-precast-concrete1.jpg


10/104

10

Concrete Masonry Unit (CMU)

Concrete Masonry Unit (CMU) also called concrete block, cement block or

foundation block is a large rectangular brick used in construction. Concrete

blocks are made from cast concrete, i.e. Portland cement and aggregate, usually

sand and fine gravel for high-density blocks. Lower density blocks may use

industrial wastes as an aggregate. Those that use cinders (fly ash or bottom ash)are called cinder blocks in the US and breeze blocks (breezeis a synonym of ash)

in Europe. Clinker blocks use clinker as aggregate. Concrete blocks that do not

contain cinders are often mistakenly called cinder or breeze blocks in everyday

speech. Lightweight blocks can also be produced using aerated concrete.


11/104

11

Concrete Damage

Physical During the construction and/or life of a concrete structure, a wide

range of man made and natural disasters can lead to physical damage to a

concrete structure. Some include:Man made -

Poor quality workmanship at the time of manufacture

Incorrect design factors

Incorrect construction materials

Abrasion, impacts or overloading

Poor subsurface conditions

Natural -

Earthquakes

Floods

Fire

Tornados


12/104

12

Concrete Damage

Carbonation -

Carbonation-initiated deterioration of concrete from Carbon dioxide in the air

can react with the calcium hydroxide in concrete to form calcium carbonate.

This process is called carbonation, which is essentially the reversal of the

chemical process of calcination of lime taking place in a cement kiln.

Carbonation of concrete is a slow and continuous process progressing from the

outer surface inward, but slows down with increasing diffusion depth.

Carbonation has two effects: it increases mechanical strength of concrete, but italso decreases alkalinity, which is essential for corrosion prevention of the

reinforcement steel. Below a pH of 10, the steel's thin layer of surface

passivation dissolves and corrosion is promoted. For the latter reason,

carbonation is an unwanted process in concrete chemistry.


13/104

Concrete Properties

What do Proceq Instrumentscover?


14/104

Product Line Concrete Testing

SilverSchmidt Concrete test hammer

Original Schmidt Concrete test hammer

Digi-Schmidt Concrete test hammer

Pundit Lab Ultrasonic instrument

Pundit Lab + Ultrasonic instrument

Profometer 5+ Rebar detector

Profoscope(+) Rebar detector

Canin+ Corrosion analyzer

Resipod Surface resistivity meter

Torrent Permeability tester

Dyna Pull-off tester

Hygropin Humidity tester


15/104

Profometer 5+ Rebar Detection System

Rebar detectors

For a user-friendly, compact and accurate way to detect reinforcement bars

and mesh, to measure their cover depth and estimate the bar diameter,

Profometer 5+is simply the best solution available!

Memory Non-volatile memory for 40000 measured values

Display LCD with backlight option

Interface RS232 or with adapter for USB port on PC

Software ProVista for downloading data and evaluation on PC

Batteries 6 x 1.5 V for 45 h operation; 30 h with backlight on

Universal probe

Measuring process:

eddy current with

pulse induction

Display Unit

Less sensitive to

electrical fields

fluctuations in temperature

ScanCar

For functions with

displacement measurement


16/104

Profometer Measurement Method - 1

PROFOMETER 5+ uses the pulse-induction method.

Coils in the probe are periodically charged by current

pulses and thus generate a magnetic field. On thesurface of any electrically conductive material which is

in the magnetic field eddy currents are produced. They

induce a magnetic field in opposite direction. The

resulting change in voltage can be utilized for the

measurement.

Rebars that are closer to the probe or of larger size

produce a stronger magnetic field. The strongest signalalso results, when the centre line of the probe is parallel

to a bar.

During scanning the signals are

analyzed by the instrument and

corresponding information isindicated on the LCD.


17/104

Profometer 5+ Measurement Method - 2

Rebar detectors

When moving the probe across the concrete, the measured signal gets

stronger and weaker. The max. Signal Value signals the rebar.

For one single bar, e.g. the Test Block, the situation is easy. The Signal Value

starts from 0 and has a peak above the bar. For an arrangement of several

parallel bars the characteristics of the signal can be as shown above. If the

spacing of the bars is closer the curve gets rather straight or there is just one

peak in the middle of the bars. This means the bars cannot be detected individually anymore. For a clear

identification of bars a sufficient decrease of Signal Value is required.


18/104

Profometer 5+ Measurement of concrete cover depth

Rebar detectors

signal

strength

The signal value is converted

to a cover value in [mm].

The accuracy of the readingcan be improved by setting the

bar diameter.


19/104

Profometer 5+ Accuracy of the cover depth measurement

Rebar detectors

Profometer 5+ has two

detection ranges: : Bar diameter in mm

#: Bar diameter in Bar size

#

---: Lowest accuracy limit

required by the standardBS 1881: Part 204: 2 mm

or 5 %

PROFOMETER 5+

measures up to 50 % more

accurately than required bythis standard.

The accuracy of the

concrete cover indication

refers to individual bars.


20/104

Rebar detectors

Profometer 5+ Rebar Diameter ( ) Estimation

Diameters can estimated for cover depth not exceeding 64mm / 2.5 inch Neighbouring Bar space of 150 mm will influence measurements.

Compensation of Bar Spacing should be entered in Rebar Locators to improve

accuracy.


21/104

Profometer 5+ Resolution

Rebar detectors

The resolution defines how

close together the bars can beand still allow a measurement.

The spacing between the bars determines the maximum depth at which bars of

a specific diameter can be distinguished. This is for parallel bars in the same layer.

e.g. In order to distinguish a 10mm diameter bar at a depth of 100mm, the bar

spacing has to be at least 125mm when measuring on the large range.

magnetic

field


22/104

Profometer 5+ Determining the bar diameter

Rebar detectors

Locate and mark the rebar grid.

Place probe directly over a bar with sufficient spacing and press the up

arrow to record the bar diameter.

When measuring the diameter the influence of neighbouring parallel bars

can be corrected using neighbouring bar correction. correction.

(for spacing a from 50 mm to 130mm)


23/104

Profometer 5+ Corrections on the cover measurements

Rebar detectors

For certain rebar arrangements( see figure

beside) the Profometer 5+ allows the so

called 2-layer correction on the cover

measurements.

D1 is the diameter of the first layer

(closer to the surface)

D2 is the diameter of the second layer


24/104

Profometer 5+ Calibration of the equipment

Rebar detectors

A simple check can be carried

out by use of a Test Block.

Test Block


25/104

Profometer 5+ Model SCANLOG

Rebar detectors

Same display unit, but more functions The Scanlog model allows the

arrangement of rebars to be mapped out

Display of concrete cover of a large area Probe attached to ScanCar


26/104

ProVista Function CyberScan with Scanlog

Rebar detectors

Data Transfer &

Processing with ProVista,

allows a representation of

the grid to be displayed

showing the cover by

means of a colour code.


27/104

ProVista Measurement with Grid Model Scanlog

Rebar detectors

Data Transfer &

Processing with

ProVista, allows a large

areas to be displayed

showing the cover by

means of a colour code.


28/104

Profoscope(+) Overview of Major Selling Features

Rebar detectors

Unique Mid-Point Detection

Fully Integrated Handheld Device

Real Time Bar Detection

Differential Measuring Technology based on Pulse Induction Method

Interactive Bar Searching Aid

Supports European, Americas and Asian Markets

Complies with BS1881:204 Standard


29/104

Profoscope(+) Overview

Rebar detectors

Control Unit 4 Buttons Sight, Sound and Intelligence

Power on / off

Zeroing

Navigation Keys

Function

Measurement

Centre

LED Indicator

Display

Center line


30/104

Profoscope(+) Icon Settings Menu

Rebar detectors

Measuring

Range

Bar

Diameter

Audio

Settings

Regional

Settings

Neighboring Bar

Correction

Minimum

Cover

Memory


31/104

Profoscope(+) Display Measuring Screen

Rebar detectors

Range

active

Default Bar

Diameter

Cover ValueBar Diameter

Battery

Status

Measuring

Unit

CenterlineRebar

Position

Rebar

space / Cover


32/104

Profoscope(+) Rebar detection

Rebar detectors

Searching for Rebars Rebar has been centered

Arrows indicate proximity ofrebars off-screen

Diameter Estimation


33/104

Profoscope(+) Distinguish between balanced Situations

Rebar detectorsCrossing a rebar Crossing a Midpoint

Signal from Bars

Display

Scope from right

Arrow up

Scope moves left

Arrow down Scope moves rightArrow up

Arrow undefined above rebar

Scope from leftArrow down

Arrow undefined above rebar


34/104

Profoscope(+) Rebar Location / Mid Point

Rebar detectors


35/104

Profoscope+ with Profolink

Rebar detectors

Memory key

Up to 500 measuring

series can be stored


36/104

Reinforcing Bar Cover

Rebar detectors

f C


37/104


Rebar detectors

R i f i B C


38/104

Concrete Cover

Survey


Testing


39/104

Testing

How am I planning to present the data?

What is my client expecting?

Questions to Ask


40/104

Questions to Ask

Know your client:

Learn all about your client as you can

Use the internet

What is important to the client?

Offer something that makes you stand out

Build a relationship that goes beyond client/vender

Communicate regularly talk rather than text

Use the same style of communication a picture tells a million words

Questions to Ask


41/104

Questions to Ask

Client Expectation

Education: The First Line of Defense

Keep a Proper Perspective

Know your instruments

Expect the unexpected

A li ti Pi t


42/104

Application Pictures

Rebar detectors

Profometer 5+Profometer 5+

Profoscope (+) Profoscope (+)


43/104


44/104

Ultrasonic Testing of Concrete


45/104

CNS Electronics

launched the first Pundit

in 1972

In 1997 CNS Farnell was formed and

the Pundit evolved unti l

Pundit 6

Pundit PC

Pundit

Plus

Pundit 7

Ultrasonic Pulse Velocity


46/104


Described in ASTM C597 Pulser sends a short-duration, high voltage to the transducer which

vibrates at it resonant frequency

A switch records when the pulse is generated

The transducer vibration is then transferred to the concrete through the

couplant material

The vibrational pulse than travels through the concrete and is picked up

by a receiver on the other face of the structure



47/104


Typical measurement is the time of flight of the pulse from one transducer to

the other Attenuation of the ultrasonic requires an oscilloscope to display the signal

The pulse velocity (Dist/time) is proportional to the square root of the elastic

modulus and inversely proportional to the square root of the pass density of

the concrete



48/104


The principle of test is that the velocity of sound in a solid

material, V, is a function of the square root of the ratio of itsmodulus of elasticity, E, to its density (p),

V = f (gE/p)1/2

where g is the gravity acceleration.

In the test, the time the pulses take to travel through concrete is

recorded. Then, the velocity is calculated as:

V = L/T (2) where

V= pulse velocity (ft/s), L= length (ft), and T= effective time (s),

which is the measured time minus the zero time correction

Ultrasonic Pulse Velocity Principle Influences


49/104

Ultrasonic Pulse Velocity Principle - Influences

Anything that affects the dynamic modulus of elasticity or

the density affects the pulse velocity reading.

Rebars are a major factor. Ultrasonic waves travel

much faster through steel than through concrete, so

rebars should be avoided.

Moisture content and water/ cement ratio has a large

effect, especially during curing. This relationship can be

used to determine strength development during curing.

Temperature has an effect but not in the range10C to 30C.

Two references are recommended for further reading on influencing factors.BS 1881: Part 203 and

Handbook o n non -destructive testing of concrete Malhotra, Carino

Transmitting through Concrete


50/104


Tc = Tp + Ta Tc = Transmit time through the concrete

Tp = Transmit time through paste

Ta = Transmit time through aggregate



51/104

Transmitting through ConcreteWater/Cement Ratio

High w/c RatioLower PV

(Lower Strengths)No attempt should be made to estimated the strengthof concrete from UPV values unless a prior

relationship has been established.



52/104


Other Items to Consider:

Age of concrete Amount of reinforcement

Orientation of reinforcement

Maximum size aggregate Strength of concrete

Admixtures used in the mix

Any difference in concrete



53/104


The influence of path length will be negligible provided it is not less than100mm when 20mm size aggregate is used or less than 150mm for 40mm size

aggregate.

Pulse velocity will not be influenced by the shape of the specimen, provided itsleast lateral dimension (i.e. its dimension measured at right angles to the pulsepath) is not less than the wavelength of the pulse vibrations. For pulse of 50Hzfrequency, this corresponds to a least lateral dimension of about 80mm.

The velocity of pulses in steel bar is generally higher than they are in concrete.For this reason pulse velocity measurements made in the vicinity of reinforcingsteel may be high and not representative of the concrete. The influence of thereinforcement is generally small if the bars runs in a direction at right angles tothe pulse path and the quantity of steel is small in relation to the path length.

The moisture content of the concrete can have a small but significant influenceon the pulse velocity.

Transmitting through Concrete Resolution


54/104

Transmitting through Concrete Resolution

The typical resolution is approximately the wavelength = /2

62 kHz transducer = 25 mm



Martin, J. Hardy, Usmani, A.D. and Forde, M.C. (1995) Quantifying the defects in post-tensioned bridges using impulse

ultrasonics, Proc. 6thIns. Conf. Structural Faults and Repairs 95. Engineering Technics Press, Edinburgh, Vol 1.

Sound Wave Through Concrete


55/104

g

Direct Transmission

Indirect Transmission

Semi Direct Transmission

Typical Methods of Transmission



56/104

g

Direct Transmission



57/104

g

Direct Transmission

Principal of Transmission

Sound Concrete (ShortestTime of Flight)

Anomaly Present (IncreaseTime of Flight)

T

R

T

R



58/104

g

General Guidelines

Pulse Velocity (ft/sec) General Quality

>13,000 Very Good

10,500 13,000 Good9,500 10,500 Satisfactory(suspect)

< 9,500 Poor



59/104

g

Topographical Method



60/104

g

Topographical Method

Complete Coverage

Surface and Side

CoverageSide Coverage Only

Topographical Method of Transmission


61/104

p g p



62/104

A

A

Section A-A



63/104

Crack Depth Determination


64/104

Perpendicular crack depth iscalculated automatically from

measurements made at x

and 2x from the centre of

the crack.

x x

2x 2x

where:

T1 = Transit time at distance x

T2 = Transit time at distance 2x

Consolidation Problem


65/104

Concrete Diaphragm

Consisted of a elevated segmented box beam on concretepiers, heavily reinforced. Grout pumped from the top to fill in

the cavity monolithic structure. Some areas of poor

consolidation noted when the forms were removed



66/104



67/104



68/104



69/104

Use of Exponential Probe



70/104



71/104



72/104



73/104



74/104

Consolidation Problem Results?


75/104

Consolidation Problem Results?


76/104

Consolidation Problem Results


77/104

Second testing agency was

assigned to test the diaphragm

Testing noted poor consolidation at

the top of the diaphragm and soffit

of the precast member

Influence of post tensioning duct

was not accounted for in the first

investigation

Velocities range from 7,000 to

13,500 ft/sec

Case Study No. 2


78/104

Industrial Facility Proposed Largest Aluminum

Plant in the work

Two Power Generator Support Structures

Eight Supporting Columns for Each Structure

Approximate Side: 2 to 2.5 meters wide, by 2.5

to 3 meter deep by

6 meters Tall

Heavily Reinforced

Honeycombing noted on the surface

Chipping of affected areas underway

Proposed Test Methods


79/104


Issues with Each Proposed Test Method


80/104

Ultrasonic Pulse Velocity:

Able to transmit the signal

across the member

Limited Resolution

Proposed Testing Methods and Confirmation drilling


81/104

Initial work was performed

on a known defectivemember in an effort to

determine the resolution

Confirmation drilling was

performed to determine

accuracy of readings



82/104



83/104



84/104

Majority of the columns had isolated pockets

of unconsolidated concrete at the surface of

the column.

On the columns that had extensive

honeycombing on the surface and the

surface had been chipped, testing revealeduniform testing values throughout the test

area of the concrete column.

UPV readings co-related well with the areas

that had surface damage.

Repair details need to be certified by aresident engineer


85/104

Pundit Lab+

Working with SONREB

Strength Determination


86/104

Step 1: Select test areas for testing

Step 2: Perform UPV testing



87/104

Step 3: Remove Core and Perform Compressive Strength Test



88/104

Step 4: Input data in software and run the marco

SONREB Method - 1


89/104

SONREBcomes from the words SONic REBound.

Both ultrasonic pulse velocity and rebound hammer measurementscan 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= a.Vb.Sc

Where: a, band care constantsV is the ultrasonic pulse velocity in m/s.

Sis the rebound value.

9

1

SONREB Method - 2


90/104

Correlation using only

ultrasonic pulse velocity.

Correlation coefficient 0.71

9

2

Correlation using only rebound hammer values.

Correlation coeffic ient 0.78

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

improvement in strength estimate that can be expected.

The SONREBfunction for the same set of data gave:

fck = 8.314x10-11.V2.8096.S0.8602

with a correlation coefficient of 0.88.

SONREB Method - 3


91/104

The user has three options for working with SONREB curves.

9

3

Decreasing reliability

Decreasing reliability

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 always possible practically.

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.

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.

SONREB Method Option 1


92/104

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.

9

4

Creating a SONREB curve for the actual concrete under test.sequires a

reasonable amount of cubes or cylinders or cores.



93/104

9

5

When you have sufficient data points you can calculate

the SONREB curve.

In this example, 16 cubes were used.

The SONREB coefficients can be determined using an

array function in EXCEL called LINEST.

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



94/104

9

6



95/104

9

7



96/104

9

8



97/104

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.

9

9

Correlation Author

fck= 7.87610-19V4.636S1.747 Lenzi, Versari, Zambrini (2010)

fck= 7.69510-11V2.6S1.4 RILEM-NDT4 (1993)

fck= 1.210-9V2.446S1.058 Di Leo e Pascale (1994)

fck= 1.5110-7V0.8084S1.8815 Masi (2005)

fck= 8.0610-8V1.85S1.246 Gasparik (1992)

fck= 0.0056 V1.439S1.769 CECS21 standard (rounded

aggregate particles) (Note! V in km/s)

fck= 0.0162 V1.656S1.410 CECS21 standard (crushed

aggregate particles) (Note! V in km/s)



98/104

1

0

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.

SONREB Method Pundit Lab+


99/104

In PunditLink Device/Conversion Curves either select or create

a SONREB curve.

1

0

The display

shows the

limiting values

for a rebound

value of 10 and90.

All other rebound

values will lie

between the twolimits.



100/104

In this example the curve sr_Gasp has been selected.

1

0

Upload this

curve onto the

Pundit Lab+



101/104

1

0

Perform the reboundhammer 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 with whichever typeof hammer is to be used.



102/104

1

0

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 cornerof the screen.

Click on this symbol to

enter the rebound value

determined in the previousstep.



103/104

1

0

Perform the pulse velocity

measurement.

Once the measurement

has been made, clicking onthe up arrow of the

navigation key switches the

display between pulse

velocity and compressive

strength.


104/104

QUESTIONS

proceq seminar 05 2013 covermeter upv and sonreb malcom lim

Documents

concrete mix

water water

poured concrete

limitation concrete

hardened concrete

sonreb malcom lim

steelreinforced concrete

covermeter upv