NAVAL CORROSION CONFERENCE ROLE OF MIGRATORY CORROSION INHIBITORS FOR PROTECTING EMBEDDED AND EXPOSED STEEL PRESENTED AT MEGA RUST 2015 NAVAL CORROSION CONFERENCE June 23 to 25, 2015 NEWPORT NEWS, VA PRESENTED BY ROBERT WALDE SURTREAT HOLDING, LLC

Cement Chemistry Porosity –Cement Phase 20% (W/C 0.5) – Penetration of water, air (oxygen and carbon dioxide), Chlorides (CIˉ), other. Alkalinity – pH 13 – Hydroxyl ions (OHˉ) – Inhibit steel corrosion. Carbonation - Reduce pH – Ca(OH)2 + CO2 → CaCO3+H2O pH – 13 to pH – 8

Reinforcing Steel Corrosion Reinforcing Steel Corrosion – Major Cause of Concrete Structure Failure Steel Corrosion Mechanism and Impact Electrochemical oxidation process Inhibited by cement alkalinity and cover Accelerated by cement chloride, air and moisture content Types of corrosion Micro cell – same rebar Macro cell – different rebar Uniform – exposed steel Pitting – most common Feo Fe++ + 2e- Anodic cell H2O + O 2OH- Cathodic cell Feo + H2O + O Fe(OH)2 + 2e- Equilibrium cell Fe2O3 Expands causing concrete delamination and spalling

TYPES AND MECHANISMS OF MIGRATORY CORROSION INHIBITORS INORGANIC TYPE MIGRATE IN THE IONIC PHASE FUNCTION AT THE ANODIC CORROSION SITE CHEMICAL TYPES ARE SILICATES AND NITRITES ORGANIC TYPE MIGRATE IN THE VAPOR PHASE FUNCTION AT BOTH ANODIC AND CATHODIC SITES CHEMICAL TYPES ARE AMINE CARBOXYLATES AND AMINE ALCOHOLS

Reinforced Concrete Micro Structure

METHODS FOR UTILIZING MIGRATORY CORROSION INHIBITORS SURFACE APPLIED ON REINFORCED CONCRETE Inorganic and organic types used ADDED TO CONCRETE AND SHOTCRETE MIX DIRECT APPLICATION ON STEEL Organic type dissolved in oil INDIRECT APPLICATION ON STEEL Organic types placed in enclosed space or on packaging ADDITION TO STEEL SURFACE COATING Organic type added to coating formulation

APPLICATION OF MIGRATORY CORROSION INHIBITOR ON BRIDGE DECK

CORROSION MEASUREMENT METHODS ELECTRO-PHYSICAL METHODS DIRECT CORROSION CURRENT FLOW FROM ANODE TO CATHODE ASTM G109 MEASURES MACRO-CELL CURRENT INDIRECT MEASUREMENT OF CORROSION CURRENT BY POLARIZATION RESISTANCE ASTM G 59 Icr =Vp/Pr GALVAPLUSE INSTRUMENT HALF-CELL POTENTIAL ASTM C876-09 MEASURES POTENTIAL FOR CORROSION OR DRIVING FORCE FOR CORROSION IF CONDITIONS FOR CORROSION EXIST. DIRECT OBSERVATION OF PROTECTIVE COATING SURFACES DEGREE OF CREEP FROM X SCRIBED AREA ASTM D1654 SCORE ON SCALE OF 10 TO 1 DEGREE OF SURFACE RUST ASTM D610 SCORE ON SCALE OF 10 TO 1

GALVAPLUSE CORROSION RATE MEASUREMENT

NASA/KSC JOINT R&D EVALUATION OF TWO NEW MIGRATORY REBAR CORROSION INHIBITORS IN 1996 MIGRATORY CORROSION INHIBITORS EVALUATED Inorganic Water Soluble Anodic Type Applied at 100SF/Gal Organic Alcohol Soluble Anodic/Cathodic Type Applied at 100SF/Gal TEST METHOD USED Macro-cell Designed To Measure Half-cell Potential and Corrosion Current Design And Method Similar To ASTM G109 Chloride Activated Rebar (Anodic State) At 1 and 2 Inches From Surface Cathodic State Rebar 5 Inches From Surface Half-cell Measured Through Ports In Test Block

NASA/KSC INORGANIC MIGRATORY CORROSION INHIBITOR PERFORMANCE MEASUREMENT

NASA/KSC ORGANIC VAPOR PHASE MIGRATORY CORROSION INHIBITOR PERFORMANCE MEASUREMENT

CORPS OF ENGINEERS OKINAWA BRIDGE AND GIRDER RESTORATION PROJECT USING SURFACE APPLIED MIGRATORY CORROSION INHIBITORS STRUCTURE TYPES Fuel depot patrol bridges Warehouse ring girders AGE OF STRUCTURES Built in the 1950’s REBAR CORROSION CONDITION Carbonation front has reached the rebar level Concrete spalling exposed rusty rebar SURFACE APPLIED MIGRATORY CORROSION INHIBITORS APPLIED Inorganic/anodic /silicate type Organic/anodic/cathodic/aminecarboxylate type Application Rates 100SF/gal

Initial Conditions 1 ft. Structures were experiencing significant rebar corrosion prior to rehabilitation. Corrosion appeared to be due to carbonation of the concrete rather than chloride-induced corrosion

Initial Conditions Ring girder of warehouse at Naha Port Girder shows signs of deterioration due to rebar corrosion and general breakdown of the concrete cement structure. Spalling, efflorescence, delamination, rust stains and other common signs of concrete failure.

CORROSION RATE MEASUREMENTS ON REINFORCED CONCRETE BEAM BEFORE AND AFTER APPLICATION OF MIGRATORY CORROSION SYSTEM ON CONCRETE SURFACE MIGRATORY CORROSION SYSTEMS Organic, Duel Function, Vapor Phase Inhibitor Applied First At 100SF/Gal Of Formulated Product Anodic Ionic Phase Migratory Inhibitor Applied Second At 100SF/Gal Of Formulated Product CORROSION RATE IN MICROMETERS OF STEEL LOST PER YEAR BY CONVERSION OF CORROSION CURRENT IN MICROAMPS PER CM2 BEFORE APPLICATION AFTER APPLICATION JANUARY 2007 JULY 2007 JULY 2010 MEDIAN CORROSION 41 6 5 RATE AVERAGE CORROSION 61 23 14

CORROSION RATE MEASUREMENTS ON REINFORCED CONCRETE BRIDGE BEFORE AND AFTER APPLICATION OF MIGRATORY CORROSION SYSTEM ON CONCRETE SURFACE MIGRATORY CORROSION SYSTEMS Organic, Duel Function, Vapor Phase Inhibitor Applied First At 100SF/Gal Of Formulated Product Anodic Ionic Phase Migratory Inhibitor Applied Second At 100SF/Gal Of Formulated Product CORROSION RATE IN MICROMETERS OF STEEL LOST PER YEAR BY CONVERSION OF CORROSION CURRENT IN MICROAMPS PER CM2 BEFORE APPLICATION AFTER APPLICATION JANUARY 2007 JULY 2007 JULY 2010 MEDIAN CORROSION 30 8 7 RATE AVERAGE CORROSION 37 13 7

APPLICATION OF MIGRATORY CORROSION INHIBITORS ON PARKING GARAGE DECK Corrosion Current Measured on 26 Points Over Rebar Mat Before And After Application of Inhibitors Vapor Phase Inhibitor Applied At 150 Ft²/Gallon Ionic Phase Inhibitor Applied At 200 Ft²/Gallon 6.5 Months Later Corrosion Current Measured At Some 26 Points on Deck Corrosion Current Converted To Corrosion Rate 1 Micro Amps Per Cm² = 11.6 Micrometers of Rebar Steel Loss Per Year Corrosion Rates Displayed on Bar Graph

REBAR CORROSION RATE BEFORE AND AFTER INHIBITOR APPLICATION

CALCULATION OF STRUCTURE LIFETIME BASED ON REBAR CORROSION RATE Calculation Equation And Assumptions Assumptions Rebar diameter at time zero. Assume to be 20mm Percent loss in rebar diameter to reach critical structural point. Assume to be 20% or 4mm Equations With respect to diameter D = 2x10¯³ x R(t) x K x T With respect to time T = D/2x10¯³ x R(t) x K D = the loss in rebar diameter over time T T = Number of years in time for loss of the measured rebar diameter R(t) = The average corrosion rate at time zero in terms of micrometers of steel lost per year K = A factor multiplying the average corrosion rate it account for the presence of corrosion hot spots

CALCULATION OF TIME TO REACH CRITICAL STRUCTURAL POINT Corrosion Rate Measurements Before and After Application of Migratory Corrosion Inhibitors Average corrosion rate before application = 100uM/Yr. Average corrected corrosion rate after application = 28uM/Yr. Average corrosion rate before application for 5 highest point = 250uM/Yr. Ratio of average rate before application and 5 hot spot points = 2.5 K Calculation of Time in Years To Reach From Time Zero To Reach The Critical Structural Point Before And After Application of Migratory Corrosion Inhibitors T= D/2x10¯³ x R(t) x K Before application T = 4mm/2x10¯³ x 100 x 2.5 = 8 years After application T = 4mm/2x10¯³ x 28 x 1.0 = 72 years

PAINT PLUS MIGRATORY CORROSION INHIBITOR PAINT TYPE 2 Part Epoxy Polyamide Primer, Formula 150,Type III Conformance:MIL-DTL-24441/20 MIGRATORY CORROSION INHIBITOR Type: Amine-carboxylate added to part A Concentration: 2.5weight percent of dry film solids APPLICATION Spray applied on new and pre-corroded ASTM A1008 carbon steel panels abraded with black beauty

PAINT PLUS MIGRATORY CORROSION INHIBITOR PERFORMANCE EVALUATION APPLICATION 2 To 3 Mil Film On Abraded White And Corroded Steel Panels EXPOSURE 500 Hours In Salt Fog Chamber Per ASTM B117 PERFORMANCE MEASUREMENTS Film Adhesion Per ASTM D3359 On Scale 0 To 5 Creep From X Score Per ASTM D1654 On Scale Of 0 To 10 (10 No Creep) Degree Of Rust On Smooth Side Per ASTM D610 On Scale Of 0 To10

APPLIED ON CORRODED STEEL PANELS COMPARISON OF PERFORMANCE WITH AND WITHOUT MIGRATORY INHIBITOR ADDED TO PAINT APPLIED ON CORRODED STEEL PANELS VCI TYPE CONDITION ADHESION CREEP DEGREE OF RUST Without VCI 4B 3 4 With VCI 5B 6 8

APPLIED ON WHITE STEEL PANELS COMPARISON OF PERFORMANCE WITH AND WITHOUT MIGRATORY INHIBITOR ADDED TO PAINT APPLIED ON WHITE STEEL PANELS VCI TYPE CONDITION ADHESION CREEP DEGREE RUST Without VCI 5B 5.3 3.0 With VCI Added 4B 6.3 8.8 * average of 4 panels

BENEFITS OF PAINT PLUS MIGRATORY CORROSION INHIBITOR CAN BE APPLIED ON RUST COVERED STEEL WILL MIGRATE THROUGH RUST TO WHITE METAL SURFACE AND TO HARD TO COAT RECESSED AREAS CAN PERFORM SPOT COATING MAINTENANCE WITHOUT NEED FOR SURFACE PREPARATION TO WHITE METAL USE AS PRIMER COAT FOR FINAL FINISH COAT

MIGRATORY CORROSION INHIBITORS A TOOL FOR PRESERVATION OF BRIDGES APPLY ON EXISTING REINFORCED CONCRETE STRUCTURES EXPERIENCING REBAR CORROSION TO EXTEND LIFE. ADD TO CONCRETE MIX OR ON SURFACE OF NEW STRUCTURES TO INHIBIT DAMAGE FROM FUTURE CORROSION CONDITIONS. APPLY PAINT WITH MIGRATORY CORROSION INHIBITORS ON NEW ANND CORRODED STEEL STRUCTURES AND COMPONENTS.

CREDITS FOR SUPPORT OF MIGRATORY CORROSION INHIBITOR PROJECTS JOE CURRAN, NASA CORROSION LABORATORY KENNEDY SPACE CENTER (Original Evaluation Of Migratory Corrosion Inhibitors) DAVID STEPHENSON, ASHOK KUMAR, US ARMY CORPS OF ENGINEERS, ENGINEER RESEARCH AND DEVELOPMENT CENTER (Project On Bridges Warehouse Ring Girders in Okinawa) RICH LAMPO , US ARMY CORPS OF ENGINEERS, ENGINEER RESEARCH AND DEVELOPMENT CENTER ( Project on evaluation of addition of vapor phase corrosion inhibitors to steel primer)