Evaluation of Test Methods for Permeability (Transport)and Development of Performance Guidelines for Durability

Tommy Nantung (INDOT), Jason Weiss (Purdue), Karthik Obla (NRMCA)National Concrete Consortium, Baton Rouge, April 8, 2008

Evaluation of Test Methods for Permeability (Transport)and Development of Performance Guidelines for Durability

Tommy Nantung (INDOT), Jason Weiss (Purdue), Karthik Obla (NRMCA)National Concrete Consortium, Baton Rouge, April 8, 2008

Motivation for the StudyMotivation for the Study

Concrete specified and placed - prescriptive specifications Shift from prescriptive specifications to end result or performance based specifications. PRS

Slowed by a lack of testing procedures, especially relate to transport

Motivation for the StudyMotivation for the Study

Prescriptive specificationw/cm = 0.40Cover (1.5 to 2.5 in.), chloride ion limits20% fly ash, 30% slag etc.705 lb/yd3

Corrosion inhibitor

Replace prescription with performance requirement for corrosion resistance

The Link Between Durability and TransportThe Link Between Durability and Transport

Each potential durability issue can be related in part to water penetration

Freeze-thaw, chloride penetration and corrosion, alkali aggregate attack, and sulfate attack.

To specify more durable concrete, tests are needed:

Qualify the resistance of the concrete to water (or aggressive fluid) penetration.

Project ObjectivesProject Objectives

Develop test procedure(s)Directly evaluates the transport properties of concrete and relates these to anticipated performance with the use of exposure conditions

Evaluate existing transport test proceduresDevelop new, or improve test procedures Correlate transport properties and existing ‘durability’ tests.Develop guidelines to relate

Permeability, exposure conditions, and field performance for use in specifications and quality control

Project Scope Project Scope

Phase ILiterature Review of Concrete Permeability (Transport) Test Procedures and Models that Link Tests with Performance

Phase IIEvaluate Promising Concrete Permeability (Transport) Tests and Recommend Procedures for Further Use

Phase IIIDevelop New or Improve Existing Permeability (Transport) Testing Procedures.Develop Protocols to Use these Tests, Evaluate the Precision and Bias of these Tests

Project Scope Project Scope

Phase IVCorrelate Permeability (Transport) Tests with Laboratory Tests that Evaluate Durability

Phase VDevelop Performance Criteria Guidelines that Relate Permeability (Transport) Tests with Exposure Conditions and Performance

Phase VIPreparation of Technology Transfer and Educational Materials

Example of Proposed Performance TestsExample of Proposed Performance Tests

Rapid Index TestsRCP (ASTM C 1202) RMT (AASHTO TP 64) Sorptivity (ASTM C 1585) Gas Permeability (RILEM-CEMBUREAU)

Science-based TestsChloride Diffusion (ASTM C 1556) Modified Chloride Diffusion (ASTM C 1556)

General Modeling ApproachGeneral Modeling Approach

Step 1

Assess Materials

Using Standard

AASHTO or ASTM tests

Step 2

Transform Test Results

into Material

Properties

Step 4

Use Service Life to

Establish Performance

Grades

Step 3

RelateMaterial

Properties to Service Life

Using Exposure

For the main characteristics investigated in this work the following approach was used for modeling

•Chloride Permeability and Corrosion•Freeze Thaw Durability

Barde et al. 2006

Corrosion Model ApproachCorrosion Model Approach

Step 1

Assess Materials

Using Standard

AASHTO or ASTM tests

Step 2

Transform Test Results

into Material

Properties

Step 4

Use Service Life to

Establish Performance

Grades

Step 3

RelateMaterial

Properties to Service Life

Using Exposure

Step 1

Measurement using RCPT

Results in Coulomb

Step 2

Transform RCPT results to Diffusivity

(D) (m2/sec)

Step 4

Service life(tlife) to

Material Grades

Grades

Step 3

Relate Diffusivity

to Life

D (m2/sec) to Years

Barde et al. 2006

20.90.70.50.3

Secondary Sorptivity (x10-3 mm/s0.5)

10

100

20

30

50

Serv

ice

Life

(Yea

rs) Entrained Air %

0.0 % Air

5.0 % Air6.5 % Air8.0 % Air

Performance Grades – ExamplePerformance Grades – Example

GRADE 4

GRADE 3

GRADE 2

GRADE 1

Barde et al. 2006

Recent DevelopmentRecent Development

ASTM C1202, Standard Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion PenetrationASTM C1556, Standard Test Method for Determining the Apparent Chloride Diffusion Coefficient of Cementitious Materials by Bulk DiffusionChallenge

Can the RCPT results (< 90 days) rank mixtures in the same order as the chloride diffusion test?

Recent DevelopmentRecent Development

Scenario 1Low pore solution conductivityOpen pore structureLow RCPT result and high chloride diffusion coefficient

Scenario 2Very high pore solution conductivityTight pore structureHigh RCPT result and low chloride diffusion coefficient

Recent DevelopmentRecent Development

HypothesisAccept mixtures with high chloride ion diffusion coefficients and low pore solution conductivitiesReject mixtures with low chloride ion diffusion and high pore solution conductivities

The conductivity of the pore solution has no influence on chloride ion transport measured with ASTM C 1556Specifying concrete mixtures with low RCPT values are not a sound approach

Preliminary ResultsPreliminary Results

ACC.

ACC.

ACC.

ACC.

ACC.

200

400

600

800

1000

1200

1400

1600

1800

2000

28 46 64 81 99

Age, days

Char

ge p

asse

d, c

oulo

mbs

SL50/0.40

SL23/0.40

SF12/0.63

SF10/0.40

SF12/0.60

X

Preliminary ResultsPreliminary Results

0.0

0.5

1.0

1.5

2.0

2.5

0 5 10 15 20 25 30

Depth, mm

Cl-

(mas

s %

)

SL50/0.40

SL23/0.40

SF12/0.63

SF10/0.40

SF12/0.60

X

Preliminary ResultsPreliminary Results

Diffusion Coefficient (Deff) @ 113 d vs Rcpt @ 56 d

SL50/0.40SL23/0.40

SF12/0.63

SF10/0.40

SF12/0.60

R2 = 0.99

0.0E+00

1.0E-12

2.0E-12

3.0E-12

4.0E-12

5.0E-12

6.0E-12

7.0E-12

0 200 400 600 800 1000 1200 1400

Rcpt, coulombs

Def

f m2 /s

Preliminary ResultsPreliminary Results

Diffusion Coefficient (Deff) @ 113 d vs Rcpt @ 99 d

SL50/0.40SL23/0.40

SF12/0.63

SF10/0.40

SF12/0.60

R2 = 0.99

0.0E+00

1.0E-12

2.0E-12

3.0E-12

4.0E-12

5.0E-12

6.0E-12

7.0E-12

0 200 400 600 800 1000 1200 1400

Rcpt, coulombs

Def

f. m

2 /s

Preliminary ConclusionsPreliminary Conclusions

Mixture with “very low” (975 Coulombs) chloride ion penetrability (ASTM C 1202) has a high chloride ion diffusion coefficient (SF12/0.63)Mixtures with “higher” chloride ion penetrability (ASTM C 1202) has a lower chloride diffusion (SL23/0.40 vs SF12/0.60)The RCPT does not rank mixtures in the same order as the chloride ion diffusion.

Preliminary Result from PurduePreliminary Result from Purdue

Measurement of Water Absorption Using a Semi-Automated ProcedureSignificance of Sample OrientationDetailed Analysis of Water Penetration Depth at Early Ages

Sorption MeasurementsSorption Measurements

0 24 48 72 96 120 144 168 192

Time (Hr)

0

10

20

30

40

50

60

Wat

er A

bsor

ptio

n (g

)

0 24 48 72 96 120 144 168 192

0

10

20

30

40

50

60Average, Proposed procedureAvergae, Standard procedure

Specimen #1: w/c = 0.4, 12 months of conditining

Specimen #3: w/c = 0.5, 3 months of conditining

Specimen #2: w/c = 0.4, 3 months of conditining

Sorptions Measured in Cracked ConcreteSorptions Measured in Cracked Concrete

0 50 100 150 200 250

Time (min.1/2)

0

2

4

6

8

Cum

. Vol

. of W

ater

Abs

orbe

d P

er S

urfa

ce A

rea

(mm

3 /m

m2 )

E/E00.100.690.861.00

Sealing – Side epoxy sealed, tape bonded and sealed

Preconditioning: 14 days @ 20ºC, 50% RH

Mass gain - recorded regularly

Test Methods ComparedTest Methods Compared

(a) Ponding Test (b) Capillary Rise (c) Submerged Test

102 mm51

mm

Water

Spe

cim

en

Duct Tape

Epo

xy C

oatin

g

Sealed Container

Several Different Sorption tests were evaluated to relate this property to exposure conditions

Typical ResultsTypical Results

Absorption in damaged samplesRate of absorption can change significantly Total absorption is very similar

0 50 100 150 200 250Time (min.1/2)

0

2

4

6

8

Cum

. Vol

. of W

ater

Abs

orbe

d P

er S

urfa

ce A

rea

(mm

3 /m

m2 )

Submerged TestPonding TestCapillary Rise

Hardened Air: 4.5%Vol.E/E0 = 0.4

Slope: Initial Sorptivity

Total Water Absorption

Typical Absorption MeasurementsTypical Absorption Measurements

0.60 0.70 0.80 0.90 1.00 1.10Ratio of X-Ray Intensity (IWET/IDRY)

16

14

12

10

8

6

4

2

0

Dep

th o

f Pen

etra

tion

(mm

)

Dry State4 Minutes11 Minutes18 Minutes25 Minutes32 Minutes39 Minutes50 Minutes57 Minutes

Change in normalized intensity with ingress

Depth of PenetrationDepth of Penetration

Sant et al. 2008

0.0 0.2 0.4 0.6 0.8 1.0Time from Ponding (h0.5)

0

2

4

6

8

Dep

th o

f Pen

etra

tion

(mm

) DI-Water0.2%SRA5%SRA

SummarySummary

Work is currently assessing fluid transport in concreteWork shown today describes water sorption techniques that show promiseAdditional Work (Not Shown) is investigating diffusion and permeability

Project Team Project Team

INDOT Tommy E. Nantung, Ph.D., P.E., Section Manager

Purdue University Jason Weiss, Ph.D., Professor and Associate HeadJan Olek, Ph.D., P.E., ProfessorMark Baker is the Laboratory ManagerPost Doctoral Assistants, Graduate Assistants and Hourly Labor

NRMCAKarthik Obla, Ph.D., P.E. Senior Director of Research and Materials Engineering,Haejin Kim, Laboratory Manager/Materials EngineerSoliman Ben Barka, Senior Laboratory TechnicianColin Lobo, Ph.D., P.E. Vice President of EngineeringGary Mullings Senior Director of Operations and Compliance.

Project FundingProject Funding

Funding$883,000 Pooled Fund

4 year Project $25,000 each year for the first three years and $12,000 for the fourth year.

$100,000 FHWA $335,100 Matching Dollars from Industry$135,515 In Kind Matching

Evaluation of Test Methods for Permeability (Transport)�and Development of Performance Guidelines for Durability�Tommy NantungMotivation for the StudyMotivation for the StudyThe Link Between Durability and TransportProject ObjectivesProject Scope Project Scope Example of Proposed Performance TestsGeneral Modeling ApproachCorrosion Model ApproachPerformance Grades – ExampleRecent DevelopmentRecent DevelopmentRecent DevelopmentPreliminary ResultsPreliminary ResultsPreliminary ResultsPreliminary ResultsPreliminary ConclusionsPreliminary Result from PurdueSorption MeasurementsSorptions Measured in Cracked ConcreteTest Methods ComparedTypical ResultsTypical Absorption MeasurementsDepth of PenetrationSummaryProject Team Project Funding