I-99 Corrosion Study (Pictures in this presentation were taken from Corvib, NDT James & Fisher Scientific Websites)

Objectives Evaluate Equipment Precision & Accuracy Evaluate Equipment Precision & Accuracy Compare Different Test Results Compare Different Test Results Concrete Resistivity Concrete Resistivity Half Cell Potential – ASTM 876 Half Cell Potential – ASTM 876 Corrosion Rate Corrosion Rate Chloride Permeability – ASTM 1202 Chloride Permeability – ASTM 1202 Acid Soluble Chloride Penetration – AASHTO T260 Acid Soluble Chloride Penetration – AASHTO T260 Environmental Factors Environmental Factors Analyze Design Factors Analyze Design Factors

Corrosion in Concrete Anode Reaction Anode Reaction Fe – 2e  Fe 2+ Cathode Reaction Cathode Reaction 2H 2 O + O 2 + 4e  4OH - H2OH2O H2OH2O O2O2 O2O2 Cl - OH - Cathode Anode e-e- e-e- Fe 2+ rust Cl -

Concrete Resistivity Related to the conductivity of concrete Related to the conductivity of concrete Defined by: Defined by: Pore Structure Pore Structure Concrete Moisture Concrete Moisture Concrete Composition Concrete Composition High Resistivity Benefits High Resistivity Benefits Concrete Diffusion Concrete Diffusion Cathodic Current Cathodic Current

Concrete Resistivity Testing Mechanism I~ V S S S Voltmeter Ammeter Alternating Current Supply Electrodes Current Flow Lines Equipotential Surface

Concrete Resistivity Types of Equipment Corvib RESI Resistivity Meter NDT James RM-8000 Resistivity Meter NDT James GeCor 6 – Sensor B

Concrete Resistivity Values Guideline Values Concerning Concrete Resistivity (Multiple Published Sources) Resitivity (kcm) (kΩ cm) Possible Corrosion Rate < 5 Very high 5 to 10 High 10 to 20 Moderate/Low >20InsignificantResitivity (kcm) (kΩ cm)Corrosion p ≤ 8 Fairly Certain 8 < p < 12 Possible p ≥ 12 Improbable Corvib RESI Resistivity Meter NDT James RM-8000 Resistivity Meter *** p > 60 kΩ cm  Corrosion Impossible

Corrosion Equipment NDT James GeCor 6 3 Linear Polarization Sensor A Corvib CANIN Corrosion Potential

Corrosion Values Guideline Values (ACI 222) to determine possibility of corrosion for a Copper-Copper Sulfate Reference Electrode Guideline Values (ACI 222) to determine possibility of corrosion for a Copper-Copper Sulfate Reference Electrode mV vs. CSEProbability of Corrosion mV vs. CSEProbability of Corrosion 0 to -200> 90% No Corrosion 0 to -200> 90% No Corrosion -200 to -350Uncertain Corrosion Activity Less than -350> 90% Corrosive Activity

Environmental Factors Relative Humidity Relative Humidity Moisture Moisture Temperature Temperature Hygrometer Pen Hygrometer Pen Moisture Meter Moisture Meter GeCor 6 – Sensor B GeCor 6 – Sensor B

Other Tests Chloride Permeability – ASTM 1202 Chloride Permeability – ASTM 1202 Acid Soluble Chloride Penetration – AASHTO T260 Acid Soluble Chloride Penetration – AASHTO T260

Corrosion Test Setup Modified AASHTO T259 Modified AASHTO T259 2’ x 2’ x 6” Slabs 2’ x 2’ x 6” Slabs 1” Clear Cover 1” Clear Cover 5/8” dia. Reinforcement Bar (#5) 5/8” dia. Reinforcement Bar (#5) Internal Thermal Couple Internal Thermal Couple Two electrical connections to rebar Two electrical connections to rebar Different Rebar Different Rebar Different Mixture Designs Different Mixture Designs

Ponding Cycles Slabs ponded every 2 weeks Slabs ponded every 2 weeks 3.0 % NaCl Salt Water Solution 3.0 % NaCl Salt Water Solution Slabs kept indoors in semi- controlled environment Slabs kept indoors in semi- controlled environment Temperature ranges: 18 to 28 C Temperature ranges: 18 to 28 C Relative Humidity ranges: 20 to 60 % Relative Humidity ranges: 20 to 60 % Currently 17 different slabs Currently 17 different slabs pts. / Slab / Week pts. / Slab / Week Overall Picture of the lab

Testing Performed Corvib Resistivity on Slab James Resistivity on Slab James Resistivity on Slab Corvib Cylinder Comparison Corvib Cylinder Comparison James Cylinder Comparison James Cylinder Comparison Environmental Tests Environmental Tests Internal Temperature Internal Temperature External Temperature External Temperature Relative Humidity Relative Humidity Moisture Moisture Corvib Corrosion Potential (Baseline Values) Corvib Corrosion Potential (Baseline Values) GeCor 6 Corrosion Potential / Rate / Resistivity (B. V.) GeCor 6 Corrosion Potential / Rate / Resistivity (B. V.) X X X X X XX X X XX X X feet 1 X

Mix Identification PC = Portland Cement PC = Portland Cement BS = Ground Granulated Blast Furnace Slag BS = Ground Granulated Blast Furnace Slag FA = Fly Ash FA = Fly Ash IP = Ipanex IP = Ipanex AQ = Aquron AQ = Aquron CC = Centre Concrete Materials CC = Centre Concrete Materials NE = New Enterprise Materials NE = New Enterprise Materials Numbers = Cementitious Percentages Numbers = Cementitious Percentages Bar Type & w/c ratio also defined Bar Type & w/c ratio also defined

28 day Results م (kΩcm)

Current Trends Corvib Comparison Test Number PC70FA27SF3 BLK SLB PC100 CHAMBER PC100 BLACK SLAB PC100 EPOXY SLAB PC100 MMFX SLAB PC70FA27SF3 CHAM. PC70FA27SF3 EPX SLB PC70FA27SF3MMFX SLB 28 / 7 Strengths (slab, PI) PC 100 = 1.13, 1.19 PC70FA27SF3 = 1.46, 1.43 Resistivity (kohm cm) Wet 14d 7d

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