Examination of physicochemical properties of organic coatings applied on concrete P.Pantazopoulou1, Th.Zafeiropoulou2, S.Kalogeropoulou1, E.Fountoukidis3, G. Batis2, K. Papadopoulos4 1. Electrical Engineering Department, Technological Educational Institute of Piraeus 2. Faculty of Chemical Engineering, National Technical University of Athens, Greece 3. Civil Engineering Department, Technological Educational Institute of Piraeus 4. Institute of Physical Chemistry, National Centre for Scientific Research, Demokritos, Athens, Greece eRA – 9, T.E.I. of Piraeus, 22-24 September 2014

Results of the evaluation methods Reinforcement’s corrosion behavior Effect of UV-radiation to coatings Liquid water and water vapor transmission rates Carbonation depth 22/9/2014 eRA-9

Schematic diagram of Strain Gauges corrosion test set-up 22/9/2014 eRA-9

Corrosion protection evaluation of coated specimens by the SG method 22/9/2014 eRA-9

Corrosion protection evaluation by the SG method of coated specimens with corrosion inhibitor 22/9/2014 eRA-9

Laboratory SG corrosion test set-up 22/9/2014 eRA-9

Effect of UltraViolet-radiation to coatings Radiation chamber Radiation source: four F15W T8 BLB lamps Radiation density: 71,7 μW·cm-2 (25 cm from the lamps) Emission spectrum: peak wavelength of about λ=350 nm Temperature during radiation: 36°C Distance of radiated specimens from the lamps: 5 cm UV-A radiation time: 1150 hours 22/9/2014 eRA-9

Coated specimens inside the radiation chamber during operation 22/9/2014 eRA-9

Photos of specimens before and after radiation 0 hours 400 hours 800 hours 1150 hours 22/9/2014 eRA-9

ISO 2409:1992(E) Cross-cut classification Description Surface appearance The edges of the cuts are completely smooth; none of the squares of the lattice is detached ̶ 1 Detachment of small flakes of the coating at the intersections of the cuts. A cross-cut area not significantly greater than 5 % is affected. 2 The coating has flaked along the edges and/or at the intersections of the cuts. A cross-cut area significantly greater than 5 %, but not significantly greater than 15 %, is affected. 3 The coating has flaked along the edges of the cuts partly or wholly in large ribbons, and/or it has flaked partly or wholly on different parts of the squares. A cross-cut area significantly greater than 15 %, but not significantly greater than 35 %, is affected. 4 The coating has flaked along the edges of the cuts in large ribbons and/or some squares have detached partly or wholly. A cross-cut area significantly greater than 35 %, but not significantly greater than 65 %, is affected. 5 Any degree of flaking that cannot even be classified by classification 4. 22/9/2014 eRA-9

Cross-cut test results - Classification of specimens before and after radiation Before radiation After radiation Coating Before tape After tape E P N 1 2 3 4 A 5 R 22/9/2014 eRA-9

Cross-cut test – Epoxy coated specimens After tape Before radiation After radiation 22/9/2014 eRA-9

Cross-cut test – Acrylic emulsion specimens After tape Before radiation After radiation 22/9/2014 eRA-9

BS EN ISO 4624:2003 Pull-off test - Classification of coatings Result A Cohesive failure of substrate A/B Adhesive failure between substrate and first coat B Cohesive failure of first coat B/C Adhesive failure between first and second coats -/Y Adhesive failure between final coat and adhesive Y Cohesive failure of adhesive Y/Z Adhesive failure between adhesive and test cylinder 22/9/2014 eRA-9

Breaking Strength (MPa) Pull-off test results, Dry Film Thickness (DFT) and classification before radiation Coating Breaking Strength (MPa) DFT (μm) Classification E 7 400 Α P N 3 250 Α/Β 70% A 4 300 Α/Β 95% R Α/Β 90% 22/9/2014 eRA-9

Breaking Strength (MPa) Pull-off test results, Dry Film Thickness (DFT) and classification after radiation Coating Breaking Strength (MPa) DFT (μm) Classification E 1,5 400 Υ P 1 Α N 5 - A 300 R 22/9/2014 eRA-9

Photos of specimens before radiation and after pull-off test 22/9/2014 eRA-9

Photos of specimens after radiation and after pull-off test 22/9/2014 eRA-9

DIN EN 1062-3: Classification of liquid water permeability values Liquid Water Transmission Rate w (kg/m2ˑh1/2) I (high) > 0,5 II (medium) 0,1 – 0,5 III (low) < 0,1 22/9/2014 eRA-9

Mean values of water permeability measured for each organic coating Liquid Water Transmission Rate (kg/m2ˑh1/2) Classification DIN EN 1062-3 E 0,06 Class III (low) P 0,02 N 0,20 Class ΙΙ (medium) A 0,60 Class Ι (high) R 0,30 22/9/2014 eRA-9

Specimens for the measurements of liquid water permeability values 22/9/2014 eRA-9

EN ISO 7783-2 Classification of water vapor transmission rate values Water Vapor Transmission Rate (g/(m2ˑd)) I (high) > 150 II (medium) 15 – 150 III (low) < 15 22/9/2014 eRA-9

Coated substrate for the water vapor transmission rate determination 22/9/2014 eRA-9

Mean values of water vapor transmission rate for each organic coating Water Vapor Transmission Rate (g/m2ˑd) Classification DIN EN ISO 7783-2 E 25 Class ΙΙ (medium) P 20 N 618 Class Ι (high) A 180 R 215 22/9/2014 eRA-9

Liquid water and water vapor transmission rate for all organic coatings 22/9/2014 eRA-9

Optimal behavior of organic coatings concerning water permeability and water vapor transmission rate High water vapor transmission rate Low water permeability Coatings with these properties prevent the ingress of water and all the factors that water may carry while allowing the escape of water vapor from the interior of the wall creating a sealing membrane, which "breathes". 22/9/2014 eRA-9

Carbonation Carbonation of concrete is due to the reaction of CO2 from the atmosphere with the Ca(OH)2 in the pore solution in the presence of moisture: H2CΟ3 + Ca(OH)2 → CaCΟ3 +2Η2Ο Carbonation leads to reduction of the pH of the pore solution makes the material less alkaline results in reinforcement corrosion 22/9/2014 eRA-9

Carbonation depth measurements Accelerated carbonation chamber conditions: T:21±2°C, RH:60±10%, CO2 concentration: 1,0%, total exposure time: 8 weeks Carbonation depth (dk) is the average distance, measured in mm, from the surface of concrete, where the carbon dioxide (CO2) has reduced the alkalinity. A phenolophthalein indicator solution is used. Carbonated mortar remains colorless. Uncarbonated mortar is colored red-purple. 22/9/2014 eRA-9

Measurement of mortars’ carbonation depth 22/9/2014 eRA-9

Carbonation depth of mortars Coating Carbonation depth (mm) 4 weeks of exposure 8 weeks of exposure O 8 12 E 2 P 1 N 7,5 11,5 A 4 6,5 R 7 9 22/9/2014 eRA-9

Protection rate (%) of coatings against carbonation 8 weeks results 22/9/2014 eRA-9

Conclusions Based on the above presented results an estimation of the properties related to the protection offered by the various organic coatings is made. The protective action of all organic coatings against corrosion of the embedded reinforcement is confirmed. According to the evaluated property differences on the effectiveness of each organic coating are revealed. The simultaneous presence of the corrosion inhibitor improves the protective ability of coatings to various degrees. 22/9/2014 eRA-9

Acknowledgements This research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: ARCHIMEDES III. Investing in knowledge society through the European Social Fund. 22/9/2014 eRA-9

Thank you for your attention! 22/9/2014 eRA-9