estimation of test methods measurement uncertainty … · estimation of test methods measurement...

ESTIMATION OF TEST METHODS ESTIMATION OF TEST METHODS MEASUREMENT UNCERTAINTY IN MEASUREMENT UNCERTAINTY IN

CONCRETE AND CLAY CONCRETE AND CLAY LABORATORYLABORATORY

Dalibor Dalibor SekuliSekulićć,, B.Sc. (Phys.)B.Sc. (Phys.)BrankaBranka TkalTkalččiićć CibociCiboci,, B.Sc. (Chem.B.Sc. (Chem. Eng.)Eng.)

EmilijaEmilija BariBariššiićć,, B.Sc. (Civ.B.Sc. (Civ. Eng.)Eng.)

LABORATORY COMPETENCE The International Conference Cavtat - Dubrovnik, Croatia, 18-20th OctoberOctober 2007.

CIVIL ENGINEERING INSTITUTE OF CROATIA


LABORATORY COMPETENCE The International Conference Cavtat 18-20th OctoberOctober 2007.

IntroductionIntroduction

HRN EN ISO/IEC 17025:2007HRN EN ISO/IEC 17025:2007TTestingesting laboratories shall have and shall apply laboratories shall have and shall apply procedures for estimating procedures for estimating ofof measurement measurement uncertaintyuncertaintyRelatedRelated documentsdocuments::

GUM - Guide to the Expression of Uncertainty in Measurement, BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML, EAILAC G-17:2002 Introducing the Concept of Uncertainty ofMeasurement in Testing in Association with the Application ofthe Standard ISO/IEC 17025EA 4/16:2004 EA guidelines on the expression of uncertainty inquantitative testing



TypeType AABBasedased on a statistical analysis of series of on a statistical analysis of series of measurements obtained in repeatability measurements obtained in repeatability conditionsconditions

TypeType BBBBasedased on known characteristics of on known characteristics of instruments and other measurement instruments and other measurement uncertainty componentsuncertainty components

MeasurementMeasurement uncertainityuncertainity typestypes



MeasurementMeasurement uncertainityuncertainity typestypesWhatWhat typetype A A andand B B resultsresults givegive ??

Type A Type BSimpleSimple estimationestimation fromfrom n n measurementsmeasurements PrerequisitePrerequisite forfor estimationestimation isis knownknown

analitycalanalitycal expressionsexpressions whichwhich connectsconnectsresultresult withwith particularparticular uncunc. . componentscomponents

AllAll measurementmeasurement uncertainityuncertainity componentscomponentsisis includedincluded exceptexcept systematicsystematic errorserrors

InclusionInclusion ofof relevantrelevant measurementmeasurementuncertainityuncertainity componentscomponents dependsdepends on on knowledgeknowledge andand expierenceexpierence

EEffectffect of individual measurement of individual measurement uncertainty componentsuncertainty components cancan´́t t bebeseparatedseparated

EstimationEstimation givesgives influence influence ofof individualindividualuncertainityuncertainity componentscomponents

InformationInformation aboutabout systematicsystematic errorerror isisloosenloosen

InformationInformation aboutabout systematicsystematic errorserrors cancanbebe accountedaccounted

ResultsResults alwaysalways includeinclude nonhomogenitynonhomogenity ofoftest test specimensspecimens

NonhomogenityNonhomogenity ofof test test specimensspecimens cancanbebe includedincluded as a as a componentcomponent



Test Test methodsmethods inin ourour laboratorylaboratory

OverOver 100 100 accreditatedaccreditated test test methodsmethodsQualitative and semiQualitative and semi--qualitative test methodsqualitative test methodsQuantitative methodsQuantitative methods

type A and type B is estimatedtype A and type B is estimatedonly type A is estimatedonly type A is estimated



QualitativeQualitative test test methodsmethods

VVisualisual inspection of damages of civil engineering inspection of damages of civil engineering structures structures VVisualisual inspection of laboratory specimens inspection of laboratory specimens exposed to temperature changes, chemicals and exposed to temperature changes, chemicals and similarsimilar influencesinfluences



QuantitativeQuantitative test test methodsmethodsTypeType A A andand typetype B B isis estimatedestimated

Examples of method categorization based on physical principles

Subgroup of test methods Test methods

HRN EN 12390-3; HRN EN 196-1HRN EN 12504-1; HRN EN 12190

HRN EN 12390-5; HRN EN 12390-6HRN EN 934-5; HRN EN 1542

ISO 6784 ; HRN U.M1.025; HRN EN 13412

EN 993-4

Included in all physical-mechanical methods

HRN EN 12390-7; HRN EN 1097-6

HRN EN ISO 15148; HRN U.M8.300;HRN EN 13057; HRN EN 480-5

Compressive strength

Tensile strength

Modulus of elasticity

Gas permeabilityGeometrical measurements

Density determination

Capillary absorption



QuantitativeQuantitative test test methodsmethodsTypeType A A isis estimatedestimated

Some test methods where only type A estimation of measurement uncertainty is appropriate

Subgroup of test methods Test methodsFresh concrete and mortar HRN EN 12350-1 to 7; HRN EN 445;

properties HRN EN 1015-3; HRN EN 13395-1to 3

Water permeability HRN EN 12390-8

Frost resistance HRN CEN/TS 12390-9; HRN U.M1.016; HRN U.M1.055; HRN EN 13581;HRN EN 13687-1; HRN EN 13687-3

Determination of carbonation depth prEN 14630; NT build 357

Determination of particle size distribution by sieving method HRN EN 933-1



ExampleExample 1 1 Determination of static modulus of elasticity in compression

12

120

llFF

AlE

−−

⋅=

L 0

Graph Relative deformation - stress

0

2

4

6

8

10

12

14

0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4

σ (mm/m)

ε (k

N/m

m2 )

F1 F2

l2

l1



ModulusModulus ofof elasticityelasticity –– typetype BBMain components of measurement uncertainty and their allowed limit values from test standard

Uncertainity component Limit value Uncertainity

Deformation measurement ±5 µε± 2 µm

0,58 μm

Specimen dimensions tolerance ± 0,5 % -Tolerance from 90° ± 0,5 mm -Flatness tolerance 0,0005 d -Load rate (0,6±0,4) N/(mm2s) -



Other components of measurement uncertainty

Uncertainity component Limit value Uncertainity

Pressure machine accuracy ± 1% up = 0,58 %

Vennier calliper accuracy ± 0,02 mm um = 0,012 mm

Extensometer fixing accuracy- Experimentally deduced

±1 mm ul0 = 0,6 mm

ModulusModulus ofof elasticityelasticity –– typetype BB



( ) ( ) ( )232

22

1 22 Flloc uCuCuC)E(u ++=

12

120

llFF

AlE

−−

⋅=( )212

12

01

llAFF

lEC

−

−=

∂∂

=

( )( )( )212

120

122

llAFFl

llEC

−

−−=

−∂∂

=

( ) ( )12

0

123

llAl

FFEC

−=

−∂∂

=

ModulusModulus ofof elasticityelasticity –– typetype BBCombined measurement uncertainty




0,E+00

1,E+05

2,E+05

3,E+05

4,E+05

5,E+05

6,E+05

7,E+05

(C1u(l0))2 (C2u(l))2 (C3u(F))2

Unc

erta

inity

con

trib

utio

n

EXTENSOMETER DEFORMATION FORCEFIXING MEASUREMENT MEASUREMENT

( ) ( ) ( )232

22

1 22 Flloc uCuCuC)E(u ++=

Contributions to measurement uncertainity




E=43,4 GPauc(E) = 0,1 GPa

Uc(E) = 0,2 GPa , k=2Ur (E) = 0,5% , k=2

Uncertainity estimation results



ModulusModulus ofof elasticityelasticity –– typetype AANo. E (GPa)1 42,92 43,03 43,64 43,55 43,36 42,67 44,48 43,69 43,410 43,2

( ) ( )nxsxs i

i =

u(E)= 0,15 GPaU (E) = 0,34 GPa , k = 2,26Ur(E) = 0,8 %, k = 2,26

)()( ii xsxu =



ModulusModulus ofof elasticityelasticity

Type A estimation gives larger resultFor Type B All sources aren´t taken into account

specimen dimensions, perpendiculary and flatnessnonlinearity of stress-strain diagram

Type A Type B

Ur(E) (%) 0,8 0,5



ExampleExample 2 2 -- Type AType A estimationestimation

Fresh concrete test methods EN 12350 (1-7)

For measurement uncertainity estimation 4 methods are selected:

HRN EN 12350-2 Consistency by Slump TestHRN EN 12350-5 Consistency by flow table testHRN EN 12350-4 DensityHRN EN 12350-5 Air content



Slump test (EN 12350-2)Uncertainty components Allowed limit values

Mould tolerances ± 2 mmCompacting rod tolerances ± 5 mmAir temperature, relative humidity 20 ± 2°C, 65 ± 5% r.h.Duration of mould lifting 5 to 10 sWay of concrete compacting Defined by standardResult reading To nearest 10 mmMeasurement process duration ≤ 150 sTime measurement accuracy ± 0,5 sRuler accuracy ± 2,5 mm

FreshFresh concreteconcrete propertiesproperties –– TypeType AA• Uncertainity components and allowed limit values for slump test



DDifficultifficult tasktaskit is almost impossible to establish analytical expression it is almost impossible to establish analytical expression following from physical laws which connects test result following from physical laws which connects test result (height of concrete, or spreading diameter) with (height of concrete, or spreading diameter) with measurement uncertainty components. measurement uncertainty components. It isnIt isn’’t practical to investigate each of these influences by t practical to investigate each of these influences by type A evaluationtype A evaluation andand thenthen combinecombine intointo typetype BB→ SolutionSolution isis TypeType A A determinationdetermination byby measurementmeasurementrepeatingrepeating




Problem: properties of fresh concrete are fast changingSolution: perform simultaneous test of fresh concrete properties




2200

2250

2300

2350

2400

2450

2500

2550

2600

1 2 3 4 5

Test No.

Dens

ity (k

g/m

3 )

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1 2 3 4 5

Test No.

Air c

onte

nt (%

)

Concrete density Air content

20

40

60

80

100

120

140

160

1 2 3 4 5

Test No.

Slu

mp

valu

e (m

m)

Consistency byslump

Ur=12,5%100

200

300

400

500

600

700

1 2 3 4 5

Test No.

Spre

adin

g (m

m)

Consistency byflow table

Ur=5,0%

Ur=0,3% Ur=13,4%





Expanded measurement uncertainty for fresh concrete methods

Fresh concrete test methodExpanded measurement

uncertainty (k=2)

Consistency by the slump test 12,5%

Consistency by the flow table 5,0%

Fresh concrete density 0,32%

Air content 13,4%




ConclusionConclusion

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