Hybrid Composites AWS
Over-coating of Steel Bridges Presented at NEBP Conference Rutgers University September 2017
Over coating NJDOT
End beam; US Route 202 over NJ Route 29 before painting
Over coating NJDOT
End beam; US Route 202 over NJ Route 29 after painting
Approval of New Products • • • •
Tests and acceptance criteria Various steps involved (NJDOT current procedure) Quality Assurance Signatures of all the components of approved products
Project Overview • • • • •
Current approved coatings; NJDOT, NEPCOAT Practice in other states New Vs Overcoating Test methods that simulate field conditions Reduction of complexity in testing that prevents competition • Cost and Time
Unique Characteristics of Possible Overcoat Locations • Harsh conditions as compared to other locations of the structural members, Need better coatings • Soaked with chemical contaminated water • Longer drying periods • Repeated soaking could increase salt concentration • Abrasion due to contaminants • More difficult to clean • Creeping from existing corroded surfaces
Specimen Preparation • Test Specimens: 2 inch by 2 inch by 12 inch (long) steel angles – Two - ½ inch diameter holes were drilled thru the angle, one inch from each edge – On the other side of the angle, a two - 1 inch long weld was placed
• The surfaces were prepared using a (hand held) steel toothed cleaning machine • For each face of the angle, five - 20.6 millimeter inner diameter, and an outer diameter of 23.8 millimeters, O-rings were attached using a water soluble glue.
Specimen Preparation • After the water soluble glue has dried, the specimens were sprayed with a NJ DOT approved epoxy mastic urethane (EU) paint system primer • After the primer has cured the ( curing time: as per manufacturer specification), the second coat was applied over the primer. • After the coating paint has cured, the O-rings were removed, leaving approximately 3 mm exposed steel around the 20mm circles, simulating possible damages that might be caused in the field
Prepared Samples
1/2 Inch Diameter Holes in Steel Specimen
O-rings Attached to Steel Specimen
1 Inch Long Welds on Steel Specimens
Exposed annular Circles exposing steel on Coated Specimen
Spray Painting System
Low Pressure Paint Spray Apparatus
Spray Painting Specimens
PosiTest® DFT Thickness Gage • Thickness Gage used for measuring the thickness of Primer and Over Coat
NJDOT Approved EU – Systems Used in the first set of tests • EU – 04 Carboline System – Primer: Carbomastic 615 – Over Coat: Carbothane 133 LV
• EU – 13 Sherwin Williams System – Primer: Epoxy Mastic Aluminum II – Over Coat: High Solids Polyurethane B65
• EU – 16 International Paint System – Primer: Bar Rust 235 – Over Coat: Devthane 359
EU – 04 Carboline System
Primer: Carbomastic 615 Over Coat: Carbothane 133 LV
EU – 13 Sherwin Williams System
Primer: Epoxy Mastic Aluminum II
Overcoat: High Solids Polyurethane B65
EU – 16 International Paint System
Primer: Bar Rust 235 Over Coat: Devthane 359
Accelerated Durability Test • The specimens were placed in a 150-gallon plastic tank with an elevated holding rack at a 17-degree angle. – “Chamber for Accelerated Testing”
• The tank had two heat lamps, two ultra-violet lights, and a recycling salt water spray system. • Next to the tank is a deepfreeze freezer with a temperature of 0 degrees Fahrenheit • Note: for Overcoating the primary damage mechanism is due to creep of rust through damaged parts of coating rather than UV damage
Details of Cycling • One part of cycling consists of wetting with salt spray and drying under UV light • Wetting with salt spray simulates the running of salt solution at supports and expansion joints. These are the prime locations for over-coating. • These two processes occur one after another for 16 consecutive hours. • After these cycling, the specimens were placed in a deep freezer at a temperature of 0 degrees Fahrenheit for eight hours. This exposure accelerates the growth of corrosion at defect locations.
Durability Testing • This process constitutes one master-cycle (24 hours per master-cycle). • After each master-cycle, the used saline solution was replaced with a new saline solution. • The specimens were also rotated a quarter turn over the long axis, and rotate one position over when placed in the tank and freezer. • After every 14 master-cycles, the specimens were cleaned and 20 millimeter pull test dollies were epoxied onto the Over Coated steel specimens. • Twenty-four hours after the epoxy has cured, pull off testing was conducted on the specimens following the guidelines of ASTM D4541.
Chamber used for Accelerated Testing
Specimens in Accelerated Testing Chamber
Specimens in Deep-Freezer
PosiTest® AT-M Manual Adhesion Tester
Testing for Adhesion Strength
20 Millimeter Pull Off Dolly: Epoxied to Over Coated Steel Specimen
20 Millimeter Pull Off Dolly: Epoxied to Over Coated Steel Specimen
Specimen Testing – Pull Test
Specimen Pull Test Result
20 Millimeter Pull Off Dolly: After Pull Off Test
20 Millimeter Pull Off Dolly: Over Coat Paint Removed After Pull Test
Typical Pull-off Test Results
Creep of Corrosion
Cycle 0
Cycle 14
Cycle 28
Cycle 42
Test Results Tensile Stress (psi)
EU-04 Carboline System 1000.00 800.00 600.00 400.00 200.00 0.00 0
10
20 30 Cycle (Days)
40
50
40
50
EU-13 Sherwin Williams System Tensile Stress (psi)
1000.00 800.00 600.00 400.00 200.00 0.00 0
10
20
30
Cycle (Days)
Further Work • The new system does provide quantitatively measurable response variable • Continue the testing to evaluate the degradation. • Establish repeatability by testing 3 more sets • Repeat for the best coating identified during Matthew Bridge study
Further work • Analyze the reduction in pull-out load (strength) to establish acceptance criteria • Number of cycles needed • Initial reduction • Does the curve become asymptotic • Can the change of slope used for acceptance • Correlation of test data to field performance
Procedure for Acceptance • Current NJDOT guidelines • Current NEPCOAT guidelines • Key features are: Samples, test results and analysis
Thank You Comments Questions ?
Over coating NJDOT
End beam; US Route 202 over NJ Route 29 before painting
Over coating NJDOT
End beam; US Route 202 over NJ Route 29 after painting
Approval of New Products • • • •
Tests and acceptance criteria Various steps involved (NJDOT current procedure) Quality Assurance Signatures of all the components of approved products
Project Overview • • • • •
Current approved coatings; NJDOT, NEPCOAT Practice in other states New Vs Overcoating Test methods that simulate field conditions Reduction of complexity in testing that prevents competition • Cost and Time
Unique Characteristics of Possible Overcoat Locations • Harsh conditions as compared to other locations of the structural members, Need better coatings • Soaked with chemical contaminated water • Longer drying periods • Repeated soaking could increase salt concentration • Abrasion due to contaminants • More difficult to clean • Creeping from existing corroded surfaces
Specimen Preparation • Test Specimens: 2 inch by 2 inch by 12 inch (long) steel angles – Two - ½ inch diameter holes were drilled thru the angle, one inch from each edge – On the other side of the angle, a two - 1 inch long weld was placed
• The surfaces were prepared using a (hand held) steel toothed cleaning machine • For each face of the angle, five - 20.6 millimeter inner diameter, and an outer diameter of 23.8 millimeters, O-rings were attached using a water soluble glue.
Specimen Preparation • After the water soluble glue has dried, the specimens were sprayed with a NJ DOT approved epoxy mastic urethane (EU) paint system primer • After the primer has cured the ( curing time: as per manufacturer specification), the second coat was applied over the primer. • After the coating paint has cured, the O-rings were removed, leaving approximately 3 mm exposed steel around the 20mm circles, simulating possible damages that might be caused in the field
Prepared Samples
1/2 Inch Diameter Holes in Steel Specimen
O-rings Attached to Steel Specimen
1 Inch Long Welds on Steel Specimens
Exposed annular Circles exposing steel on Coated Specimen
Spray Painting System
Low Pressure Paint Spray Apparatus
Spray Painting Specimens
PosiTest® DFT Thickness Gage • Thickness Gage used for measuring the thickness of Primer and Over Coat
NJDOT Approved EU – Systems Used in the first set of tests • EU – 04 Carboline System – Primer: Carbomastic 615 – Over Coat: Carbothane 133 LV
• EU – 13 Sherwin Williams System – Primer: Epoxy Mastic Aluminum II – Over Coat: High Solids Polyurethane B65
• EU – 16 International Paint System – Primer: Bar Rust 235 – Over Coat: Devthane 359
EU – 04 Carboline System
Primer: Carbomastic 615 Over Coat: Carbothane 133 LV
EU – 13 Sherwin Williams System
Primer: Epoxy Mastic Aluminum II
Overcoat: High Solids Polyurethane B65
EU – 16 International Paint System
Primer: Bar Rust 235 Over Coat: Devthane 359
Accelerated Durability Test • The specimens were placed in a 150-gallon plastic tank with an elevated holding rack at a 17-degree angle. – “Chamber for Accelerated Testing”
• The tank had two heat lamps, two ultra-violet lights, and a recycling salt water spray system. • Next to the tank is a deepfreeze freezer with a temperature of 0 degrees Fahrenheit • Note: for Overcoating the primary damage mechanism is due to creep of rust through damaged parts of coating rather than UV damage
Details of Cycling • One part of cycling consists of wetting with salt spray and drying under UV light • Wetting with salt spray simulates the running of salt solution at supports and expansion joints. These are the prime locations for over-coating. • These two processes occur one after another for 16 consecutive hours. • After these cycling, the specimens were placed in a deep freezer at a temperature of 0 degrees Fahrenheit for eight hours. This exposure accelerates the growth of corrosion at defect locations.
Durability Testing • This process constitutes one master-cycle (24 hours per master-cycle). • After each master-cycle, the used saline solution was replaced with a new saline solution. • The specimens were also rotated a quarter turn over the long axis, and rotate one position over when placed in the tank and freezer. • After every 14 master-cycles, the specimens were cleaned and 20 millimeter pull test dollies were epoxied onto the Over Coated steel specimens. • Twenty-four hours after the epoxy has cured, pull off testing was conducted on the specimens following the guidelines of ASTM D4541.
Chamber used for Accelerated Testing
Specimens in Accelerated Testing Chamber
Specimens in Deep-Freezer
PosiTest® AT-M Manual Adhesion Tester
Testing for Adhesion Strength
20 Millimeter Pull Off Dolly: Epoxied to Over Coated Steel Specimen
20 Millimeter Pull Off Dolly: Epoxied to Over Coated Steel Specimen
Specimen Testing – Pull Test
Specimen Pull Test Result
20 Millimeter Pull Off Dolly: After Pull Off Test
20 Millimeter Pull Off Dolly: Over Coat Paint Removed After Pull Test
Typical Pull-off Test Results
Creep of Corrosion
Cycle 0
Cycle 14
Cycle 28
Cycle 42
Test Results Tensile Stress (psi)
EU-04 Carboline System 1000.00 800.00 600.00 400.00 200.00 0.00 0
10
20 30 Cycle (Days)
40
50
40
50
EU-13 Sherwin Williams System Tensile Stress (psi)
1000.00 800.00 600.00 400.00 200.00 0.00 0
10
20
30
Cycle (Days)
Further Work • The new system does provide quantitatively measurable response variable • Continue the testing to evaluate the degradation. • Establish repeatability by testing 3 more sets • Repeat for the best coating identified during Matthew Bridge study
Further work • Analyze the reduction in pull-out load (strength) to establish acceptance criteria • Number of cycles needed • Initial reduction • Does the curve become asymptotic • Can the change of slope used for acceptance • Correlation of test data to field performance
Procedure for Acceptance • Current NJDOT guidelines • Current NEPCOAT guidelines • Key features are: Samples, test results and analysis
Thank You Comments Questions ?
