PRESENTED AT NATIONAL BRIDGE PRESERVATION PARTNERSHIP CONFERENCE ORLANDO, FLORIDA 2014 AUTHORS ROBERT WALDE, SURTREAT HOLDING, LLC PRESENTER RICH

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1 PRESENTED AT NATIONAL BRIDGE PRESERVATION PARTNERSHIP CONFERENCE ORLANDO, FLORIDA 2014 AUTHORS ROBERT WALDE, SURTREAT HOLDING, LLC PRESENTER RICH LAMPO, U.S. ARMY CORPS OF ENGINEERS RESEARCH LABORATORY DAVID STEPHENSON, US ARMY CORPS OF ENGINEERS RESEARCH LABORATORY JIM NICHOLS, NASA, KENNEDY SPACE CENTER

2 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 + CO 2 CaCO 3 +H 2 O ph 13 to ph 8

3 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 Fe o Fe e - Anodic cell H2O + O 2OH - Cathodic cell Fe o + H 2 O + O Fe(OH)2 + 2e - Equilibrium cell Fe 2 O 3 Expands causing concrete delamination and spalling

4 Corrosion Process on Surface of Steel

5 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

6 Reinforced Concrete Micro Structure

7 METHODS FOR UTILIZING MIGRATORY CORROSION INHIBITORS SURFACE APPLIED ON REINFORCED CONCRETE Inorganic and organic types used ADDED TO CONCRETE AND SHOTCRETE MIX Inorganic and organic types used 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

8 APPLICATION OF MIGRATORY CORROSION INHIBITOR ON BRIDGE DECK

9 MEASUREMENT OF CORROSION RATE AND DEGREE 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 Icr =Vp/Pr GALVAPLUSE INSTRUMENT HALF-CELL POTENTIAL ASTM C 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

10 GALVAPLUSE CORROSION RATE MEASUREMENT

11 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

12 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 12

13 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. 13

14 Culvert Bridge BEFORE AND AFTER APPLICATION OF CORROSION INHIBITOR DEGREE OF REBAR CORROSION CHANGE IN EXPECTED TIME FOR CORROSION DAMAGE BEFORE AND AFTER APPLICATION OF CORROSION INHIBITORS 14

15 - Ring Girder Degree of Rebar Corrosion Before and After Application of Corrosion Inhibitor System Probability of Concrete Failure Due to Rebar Corrosion Before and After Application of Corrosion Inhibitor System 15

16 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 CM 2 BEFORE APPLICATION AFTER APPLICATION JANUARY 2007 JULY 2007 JULY 2010 MEDIAN CORROSION RATE AVERAGE CORROSION RATE

17 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 CM 2 BEFORE APPLICATION AFTER APPLICATION JANUARY 2007 JULY 2007 JULY 2010 MEDIAN CORROSION RATE AVERAGE CORROSION RATE

18 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 At100SF/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

19 NASA/KSC JOINT R&D EVALUATION OF TWO NEW MIGRATORY REBAR CORROSION INHIBITORS IN 1996 PERFORMANCE RESULTS Inorganic Anodic Ionic Migratory Inhibitor REBAR FRESH CONCRETE CORROSION ACTIVE 60 DAYS LATER 12 MONTHS LATER DEPTH Potential Current Potential Current Potential Current Potential Current mv ua mv ua mv ua mv ua Organic Vapor Phase Migratory Inhibitor REBAR FRESH CONCRETE CORROSION ACTIVE 60 DAYS LATER 12 MONTHS LATER DEPTH Potential Current Potential Current Potential Current Potential Current mv ua mv ua mv ua mv ua

20 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

21 PAINT PLUS MIGRATORY CORROSION INHIBITOR APPLICATION PERFORMANCE EVALUATION 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

22 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 With VCI 5B 6 8

23 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 With VCI Added 4B * average of 4 panels

24 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

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