This technical paper describes a new testing technique called ACET (Accelerated Cyclic Electrochemical Technique) that provides a rapid characterization of coating breakdown through cyclic impedance measurements. The paper compares results from ACET testing and traditional salt fog spray testing of two epoxy-polyurethane coating systems. ACET applies cathodic polarization to induce stress on coated samples, followed by impedance spectroscopy and potential relaxation measurements to monitor coating degradation. Testing found good correlation between ACET results, which identified coating breakdown within 24 hours, and salt fog spray testing, which required 3000 hours. The faster ACET technique provides information on corrosion processes and coating failure modes not obtainable from salt fog spray testing.
The document summarizes an experiment conducted by Harrison Steel Castings Company to identify variables that affect surface oxide inclusions ("dirt") in steel castings.
The experiment collected data from 35 heats and identified 7 important variables related to dirt levels, including head height, pouring temperature, oxidizable element levels, and slag conditioner usage. Subsequent phases aimed to control these variables, introduce a new gating system, and measure the effects on dirt levels. Statistical analysis identified differences between "clean" and "dirty" heats for each variable. The experiment aims to better understand melting and pouring practices to further reduce dirt in castings.
EXPERIMENTAL INVESTIGATION OF DURABILITY TEST ON POLYMER CONCRETE(PCAshik97
Polymer concretes are a type of concrete that use polymers to replace lime-type cements as a binder.
The polymer is used in addition to portland cement to form Polymer Cement Concrete (PCC).
The composites do not contain hydrated cement phase,although Portland cement used as an aggregate or filler.
This document presents the results of a study on the drying shrinkage of concrete made with three different cement types: ordinary Portland cement (OPC), Portland pozzolana cement (PPC), and Portland slag cement (PSC). Specimens were cured in normal water or artificial seawater for periods up to 365 days. The study found that PPC and PSC concretes experienced lower drying shrinkage compared to OPC concrete in both curing conditions. Additionally, blended cement concretes exhibited better workability than OPC concrete. The improved performance of blended cement composites is attributed to the pozzolanic reactions and filler effect of supplementary cementitious materials in PPC and PSC.
The document presents research on the effect of potassium chloride (KCl) on blended cement concrete (BCC). Tests were conducted on BCC with KCl concentrations ranging from 0.5 to 14 g/l added to deionized water. The results showed that increasing KCl concentration caused retardation of initial and final cement setting times. Compressive strengths of BCC at 28 and 90 days generally increased with higher KCl concentrations, with a significant strength increase observed at 10 g/l KCl. Chloride ion permeability of BCC decreased as KCl concentration increased. X-ray diffraction analysis was performed on BCC with 10 g/l KCl to deionized water.
A Review On Development Of Flyash Based High Strength Geopolymer Concretecedmmantc5411
Geopolymer concrete is the latest development in the field of concrete technology and it is still
developing. Geopolymers are inorganic, stable, hard and non-inflammable binder. The application of
geopolymer binder are in fire resistance fiber composite, sealant industry, tooling aeronautics SPF aluminium,
foundry equipment’s, radioactive toxic waste, ceramic, bricks and other precast concrete. The current review is
aims to put forward the development in geopolymer concrete for the production high strength geopolymer
concrete having strength more than 90MPa. The development of high strength concrete is aimed to reduce
structural member sizes and for economical construction in case of long span bridges and tall buildings. Also
the use flyash in concrete to reduce green gas house emission into the atmosphere by reducing cement usage
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
EXPERIMENTAL INVESTIGATION ON USAGE OF GREY WATER IN CONCRETE PRODUCTIONAbdulRazakBH
Abstract - An experimental study has been carried out to study the workability and strength behavior of concrete made using grey water and conventional concrete both in fresh and hardened states. To conduct the study, treated water from a treatment plant at two different stages of treatment has been collected and its effect on workability and strength of a mix M20 was studied. Workability was checked by slump and compaction factor method for each set of preparation of the samples. Strength behavior was studied with reference to compression strength, split tensile strength and flexural strength of the concrete specimens by destructive methods. The result confirms that the use of secondary treated water will not alter fresh and hardened properties of the concrete significantly when compared with that prepared with potable water. The study also concludes that there may be possibilities of corrosion of reinforcement due to the organic and inorganic impurities present in the grey water. Hence concrete made using grey water is suitable for plain concrete. Key Words: Grey Water, Manufactured sand
Influence of alkaline substances (carbonates and bicarbonates of sodium) in w...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
The document summarizes an experiment conducted by Harrison Steel Castings Company to identify variables that affect surface oxide inclusions ("dirt") in steel castings.
The experiment collected data from 35 heats and identified 7 important variables related to dirt levels, including head height, pouring temperature, oxidizable element levels, and slag conditioner usage. Subsequent phases aimed to control these variables, introduce a new gating system, and measure the effects on dirt levels. Statistical analysis identified differences between "clean" and "dirty" heats for each variable. The experiment aims to better understand melting and pouring practices to further reduce dirt in castings.
EXPERIMENTAL INVESTIGATION OF DURABILITY TEST ON POLYMER CONCRETE(PCAshik97
Polymer concretes are a type of concrete that use polymers to replace lime-type cements as a binder.
The polymer is used in addition to portland cement to form Polymer Cement Concrete (PCC).
The composites do not contain hydrated cement phase,although Portland cement used as an aggregate or filler.
This document presents the results of a study on the drying shrinkage of concrete made with three different cement types: ordinary Portland cement (OPC), Portland pozzolana cement (PPC), and Portland slag cement (PSC). Specimens were cured in normal water or artificial seawater for periods up to 365 days. The study found that PPC and PSC concretes experienced lower drying shrinkage compared to OPC concrete in both curing conditions. Additionally, blended cement concretes exhibited better workability than OPC concrete. The improved performance of blended cement composites is attributed to the pozzolanic reactions and filler effect of supplementary cementitious materials in PPC and PSC.
The document presents research on the effect of potassium chloride (KCl) on blended cement concrete (BCC). Tests were conducted on BCC with KCl concentrations ranging from 0.5 to 14 g/l added to deionized water. The results showed that increasing KCl concentration caused retardation of initial and final cement setting times. Compressive strengths of BCC at 28 and 90 days generally increased with higher KCl concentrations, with a significant strength increase observed at 10 g/l KCl. Chloride ion permeability of BCC decreased as KCl concentration increased. X-ray diffraction analysis was performed on BCC with 10 g/l KCl to deionized water.
A Review On Development Of Flyash Based High Strength Geopolymer Concretecedmmantc5411
Geopolymer concrete is the latest development in the field of concrete technology and it is still
developing. Geopolymers are inorganic, stable, hard and non-inflammable binder. The application of
geopolymer binder are in fire resistance fiber composite, sealant industry, tooling aeronautics SPF aluminium,
foundry equipment’s, radioactive toxic waste, ceramic, bricks and other precast concrete. The current review is
aims to put forward the development in geopolymer concrete for the production high strength geopolymer
concrete having strength more than 90MPa. The development of high strength concrete is aimed to reduce
structural member sizes and for economical construction in case of long span bridges and tall buildings. Also
the use flyash in concrete to reduce green gas house emission into the atmosphere by reducing cement usage
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
EXPERIMENTAL INVESTIGATION ON USAGE OF GREY WATER IN CONCRETE PRODUCTIONAbdulRazakBH
Abstract - An experimental study has been carried out to study the workability and strength behavior of concrete made using grey water and conventional concrete both in fresh and hardened states. To conduct the study, treated water from a treatment plant at two different stages of treatment has been collected and its effect on workability and strength of a mix M20 was studied. Workability was checked by slump and compaction factor method for each set of preparation of the samples. Strength behavior was studied with reference to compression strength, split tensile strength and flexural strength of the concrete specimens by destructive methods. The result confirms that the use of secondary treated water will not alter fresh and hardened properties of the concrete significantly when compared with that prepared with potable water. The study also concludes that there may be possibilities of corrosion of reinforcement due to the organic and inorganic impurities present in the grey water. Hence concrete made using grey water is suitable for plain concrete. Key Words: Grey Water, Manufactured sand
Influence of alkaline substances (carbonates and bicarbonates of sodium) in w...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Experimental Studies on the Prediction of Corrosion Levels in Reinforced TMT ...IRJET Journal
The document summarizes experimental studies on predicting corrosion levels in reinforced TMT bars in normal vibrated concrete (NVC) and self-consolidating concrete (SCC) exposed to a marine environment. Specimens of NVC and SCC with TMT bars embedded were immersed in de-ionized water with varying concentrations of NaCl and MgSO4 for curing periods of 28, 45, 60, and 90 days. Corrosion levels in the TMT bars after curing were then predicted by measuring potential differences between points on the specimens using a saturated calomel electrode and open circuit potential method. The studies aimed to investigate corrosion levels in TMT bars in NVC and SCC exposed to the marine environment
Crystal Growth and Studies of Dihydrogen Phosphates of Potassium and Ammonium...IJERA Editor
A nonlinear optical (NLO) material Potassium dihydrogen phosphates (KDP) and Ammonium dihydrogen
phosphates (ADP) are grown by slow evaporation solution growth technique. The FTIR studies confirm the
presence of the functional group in the grown crystal. The optical transmittance studies show that the crystal has
transparence in the entire visible and IR region. The thermal stability of the materials was assessed by TG/DTA
analysis. The mechanical stability of the grown crystals was analyzed by Vicker’s microhardness test. The
dielectric behavior of the crystals was tested by dielectric analysis. The second harmonic generation (SHG) of
KDP is confirmed by Kurtz and Perry powder technique using Nd: YAG laser.
The document evaluates the effect of temperature on polyethylene terephthalate (PET)-coated electrolytic chromium-coated steel plates immersed in an acetic-acetate medium. Samples with flat and rippled walls were immersed at 40, 60, and 80°C. Raman spectroscopy showed the temperature had no effect on acid absorption by the PET coating. The rippled samples had greater amorphousness due to mechanical deformation during manufacturing. Higher temperatures slightly reduced crystallinity near the steel interface but did not compromise the steel plate. The medium increased failures and deterioration of manufacturing defects on the PET surface. A combination of techniques characterized the PET coating's protective capacity on the steel plates.
This document defines terminology related to soil, rock, and contained fluids. It was prepared jointly by the American Society of Civil Engineers and the American Society for Testing and Materials. The standard defines terms found in other standards issued by ASTM Committee D18 on Soil and Rock, including terms related to soil properties, soil classification, hydraulic properties, and aquifer testing.
Mechanical Properties of Concrete with Marine Sand as Partial Replacement of ...IJERA Editor
The process of depleting sources of natural aggregates challenges the production of technically and
environmentally adequate concrete. Alternative material from marine sources is good enough for the
replacement of fine aggregate in the concrete. The material was stockpiled in the open air and no washing,
drying or decontamination process was carried out. Physical and chemical properties of DMS material were
determined. All the materials used in the concrete were selected and tested as per the standard procedures of the
Indian standards. A unique design mix will be done based on the entire material test results. Different mixtures
were produced using DMS in different proportions from 15% to 100% as per the finalized trial of the design
mix. The concrete were submitted to compressive strength testsafter 7, 28 and 90 days of moist curing, as well
as flexure and splitting tensile strength tests for M-25 grade.
IRJET- Evaluation of Water Absorption and Sorptivity Properties of Fly Ash, G...IRJET Journal
1) The document evaluates the water absorption and sorptivity properties of fly ash and GGBS based geopolymer concrete with different volume fractions of glass fibers added.
2) Specimens were tested for water absorption at 30 minutes and 24 hours by measuring their saturated and dry masses. Addition of glass fibers decreased absorption rates compared to control geopolymer concrete.
3) Sorptivity testing involved measuring mass changes of specimens exposed to water over time. Sorptivity values, calculated from the slope of mass change vs square root of time, decreased with glass fiber addition, indicating a denser microstructure with fewer interconnected pores.
This document summarizes a study on the effect of various synthesis parameters on the setting time and workability of fly ash-based geopolymer paste and mortar. Specifically, it examines the effect of alkali content (Na2O/Al2O3 ratio), silica content (SiO2/Al2O3 ratio), and water-to-binder ratio. The study found that initial and final setting time decreased with increasing alkali content and water-to-binder ratio, but increased with increasing silica content. Workability, as measured by flow table tests, also decreased with higher alkali content and water-to-binder ratio. The results provide an understanding of how synthesis parameters influence
Catalyst Synthesis by Solvothermal Process (Ghanekar,Deshmukh)_Prof PN Dange-...Gandhar Ghanekar
Iron molybdate catalyst was synthesized using a solvothermal process for photocatalytic applications. Monoclinic and orthorhombic iron(II) molybdate micro-sized particles were selectively prepared based on pH, temperature, and reaction time. The catalyst has unique 3D architectures and can be used to decompose dyes and other organic contaminants photocatalytically. Parameters like pH, concentration, temperature, and time were optimized to produce the catalyst and for its application in degrading methylene blue dye. The catalyst showed potential for scale-up and other industrial applications.
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Effect of Laser Peening on the life of failure mode of a cold pilger dieLSP Technologies
The laser shock peening (LSP) process was used to impart compressive residual stresses to pilger dies made of A2 tool steel, increasing their life. X-ray diffraction analysis found LSP generated compressive stresses over 1 mm deep in treated dies. An LSP-treated die produced 300% more tubing than standard dies before failure, exhibiting altered failure from crack propagation to plastic deformation and flaking. While pitting from LSP may have influenced earlier cracking, LSP significantly extended die life through deep compressive stresses that impeded crack growth.
1) The document examines the role of various catalysts (HCl, H2SO4, CH3COOH, HF, NH4OH) in the fabrication of silica films using a sol-gel process.
2) It was found that different catalysts can have dramatic effects on the porosity, optical quality, shrinkage, thickness, structural evolution during thermal treatment, and stress of the films. For example, using H2SO4 instead of HCl as the catalyst increased the porosity of thermally treated films from 2.8% to 31%.
3) Experiments were conducted to study the effects of various catalysts on silica films fabricated via spin coating of precursor solutions and subsequent thermal
This study experimentally investigated the effects of Millenium 21 internal curing admixture on the durability and strength of concrete. Compressive strength, carbonation, and water absorption tests were performed on conventionally cured and internally cured concrete specimens at various ages. The results showed that internally cured concrete specimens had higher compressive strength at 7, 28, and 120 days compared to conventionally cured specimens. Carbonation depth was also lower in internally cured specimens at 120 days. Additionally, internally cured specimens exhibited reduced water absorption compared to conventionally cured specimens, indicating improved durability. The findings demonstrate that internal curing with Millenium 21 can enhance long-term strength and durability of concrete.
This study investigated the impact of extended curing time on the polymerization depth of fluoride-containing pit and fissure sealant materials. Specifically, it evaluated the Knoop hardness number (KHN) of the top and bottom surfaces of a conventional pit and fissure sealant and a flowable composite cured for the manufacturers' recommended time of 20 seconds as well as an extended time of 60 seconds. The flowable composite exhibited higher KHN values than the pit and fissure sealant under all curing conditions. An extended curing time of 60 seconds increased the KHN of the bottom surface and bottom/top hardness ratio of the composite but did not significantly impact the sealant. The flowable composite demonstrated
This document provides specifications for broken brick coarse aggregate for use in lime concrete. It outlines:
- The general quality requirements for the broken bricks, including that they must be well-burnt and free of impurities.
- The physical requirements for the aggregate, including specifications for grading, bulk density, impact value, water absorption, and soluble matter content.
- The sampling methods to be used.
It also includes appendices describing the test methods for determining water absorption and soluble matter content of the aggregate.
The document describes a method for fabricating copper-silver (CueAg) core-shell particles with anti-oxidation and antibacterial properties. Tartaric acid is used as a reducing and chelating agent to coat silver nanoparticles onto copper particle cores in an aqueous system. The molar ratios of [TA]/[Ag] and [Ag]/[Cu] influence the formation and uniformity of the silver coatings on the copper particles. CueAg particles prepared with a [TA]/[Ag] ratio of 0.5 and [Ag]/[Cu] ratio of at least 0.2 exhibited a uniform silver coating and significantly reduced copper oxidation when heated. Testing showed the CueAg particles had satisfactory antibacterial
IRJET-Partial Replacement of Cement with Different Additives in ConcreteIRJET Journal
1. The document discusses partial replacement of cement with different additives in concrete such as carbon black powder, calcium sulphate, and rice husk ash. Concrete cubes and cylinders were cast with different percentage replacements to study the effect on properties.
2. Testing showed that using these additives as fillers and desiccants can enhance concrete properties like density, strength, and resistance to atmospheric attack by decreasing pores in the concrete.
3. The optimum percentages of addition of these additives found to improve compressive strength were 2-5% for carbon black and up to 15% for silica fume.
Corrosion studies of colmonoy - 6 in nitric acid during gadolinium removal st...RAMASUBBU VELAYUTHAM
This document summarizes a study on the corrosion of Colmonoy-6, a nickel-based alloy used in valves and bearings of nuclear power plant moderator systems, when exposed to nitric acid conditions present during gadolinium removal from the moderator. Specimens of undiluted Colmonoy-6 deposits and Colmonoy-6 coatings on stainless steel with varying levels of dilution were exposed to a nitric acid solution at 65°C, and corrosion rates were estimated through weight loss and electrochemical measurements. Microstructural analysis found the undiluted deposit and multiple layer coatings contained more carbide and boride precipitates than single layer coatings, indicating lower dilution effects.
Durability Characteristics of Fiber Reinforced Geopolymer Concrete Incorporat...IRJET Journal
This document summarizes a study on the durability characteristics of fiber reinforced geopolymer concrete incorporating fly ash and ground granulated blast furnace slag (GGBS). Tests were conducted to determine the sulfate resistance, chloride resistance, water absorption, and abrasion resistance of the concrete. Various fiber dosages were tested. The results showed that the geopolymer concrete exhibited better durability when exposed to sulfate and chloride environments compared to ordinary Portland cement concrete. The geopolymer concrete also had lower water absorption.
Combination of urea-Sn+2 in SCP solution was examined as a corrosion inhibitor for concrete reinforced steel by potentiodynamicpolarization, surface synergist parameter and cyclic voltammetry methods comparing with urea–Zn+2 combination. A synergism parameter (SI) indicated a synergistic effect between urea and Sn+2was exist. Polarization study revealed that formulation consisting of 300 ppm urea+50 ppm Sn+2 in SCP solution provided inhibition efficiency (IF) of 85.93% while 300 ppm urea +50 ppm Zn+2 provided 82.3% IF, and this combination acts as anodic type inhibitor. Cyclic voltammetry curves showed that the steel samples immersed in this formulation has low tendency to pitting corrosion. From these results it can be concluded that urea – Sn+2 inhibitor formulation is a good corrosion n inhibitor for concrete reinforced steel, it can maintain stable passive film on steel surface even in the presence of aggressive chloride ions so it can be used instead of the high toxicityZn+2 inhibitor to improve the corrosion inhibition of urea fertilizer inhibitor.
Performance of blended corrosion inhibitors for reinforced concreteeSAT Journals
Abstract Use of chemical corrosion inhibitors has been recognized as one of the effective way of controlling rebar corrosion in reinforced cement concrete (RCC). Corrosion inhibiting admixtures fall into the specialty admixture category and are used to slow down corrosion of reinforcing steel in concrete. The addition of corrosion inhibitors to the mix, offers a viable corrosion protection measure. There are generally three groups of inhibitors: anodic, cathodic and mixed inhibitors. The effect of these chemicals on various physical properties of cement such as setting time, pH, and compressive strength needs to be explored before use. In the present investigation an attempt has been made to mix two commercially available corrosion inhibitors and evaluate its effect on setting time, pH and compressive strength. In the next part of the study electrochemical test involving the blended chemical corrosion inhibitor were also conducted on RCC slab specimen. Corrosion kinematic parameters have been estimated using potentio-dynamic polarization tests. It has been observed that the corrosion inhibitor does not have any adverse effect on physical properties of cement and cement concrete. The low corrosion current density exhibited by the inhibitor proves their potential in controlling corrosion initiation and propagation. Keywords - Corrosion inhibitors, setting time, compressive strength, corrosion kinematic parameters
Performance of blended corrosion inhibitors for reinforced concreteeSAT Publishing House
This document discusses the performance of blended corrosion inhibitors for reinforced concrete. It summarizes the results of experiments conducted to evaluate the effect of a blend of calcium nitrite and calcium hypophosphite corrosion inhibitors on the physical properties and corrosion resistance of cement and concrete. The experiments found that the corrosion inhibitor blend did not adversely affect the setting time, pH, or compressive strength of cement or concrete. Electrochemical tests also showed that the corrosion inhibitor blend reduced the corrosion current density, demonstrating its potential to control corrosion initiation and propagation in reinforced concrete.
Analyzing Adhesion of Epoxy/Steel Interlayer in Scratch TestIJERA Editor
The document summarizes a study that investigated how different parameters affect the adhesion strength of epoxy adhesives bonded to zinc-plated mild steel. Scratch tests were performed using two epoxy adhesives and zinc-plated mild steel adherends treated with different surface treatments. A Taguchi experimental design was used to test combinations of surface treatment, adhesive type, blade angle, and adhesive thickness. Results found that surface treatment and thickness were the most influential parameters, affecting scratch force by 52.4% and 19.9% respectively, and scratch energy by 44.0% and 25.6% respectively.
Experimental Studies on the Prediction of Corrosion Levels in Reinforced TMT ...IRJET Journal
The document summarizes experimental studies on predicting corrosion levels in reinforced TMT bars in normal vibrated concrete (NVC) and self-consolidating concrete (SCC) exposed to a marine environment. Specimens of NVC and SCC with TMT bars embedded were immersed in de-ionized water with varying concentrations of NaCl and MgSO4 for curing periods of 28, 45, 60, and 90 days. Corrosion levels in the TMT bars after curing were then predicted by measuring potential differences between points on the specimens using a saturated calomel electrode and open circuit potential method. The studies aimed to investigate corrosion levels in TMT bars in NVC and SCC exposed to the marine environment
Crystal Growth and Studies of Dihydrogen Phosphates of Potassium and Ammonium...IJERA Editor
A nonlinear optical (NLO) material Potassium dihydrogen phosphates (KDP) and Ammonium dihydrogen
phosphates (ADP) are grown by slow evaporation solution growth technique. The FTIR studies confirm the
presence of the functional group in the grown crystal. The optical transmittance studies show that the crystal has
transparence in the entire visible and IR region. The thermal stability of the materials was assessed by TG/DTA
analysis. The mechanical stability of the grown crystals was analyzed by Vicker’s microhardness test. The
dielectric behavior of the crystals was tested by dielectric analysis. The second harmonic generation (SHG) of
KDP is confirmed by Kurtz and Perry powder technique using Nd: YAG laser.
The document evaluates the effect of temperature on polyethylene terephthalate (PET)-coated electrolytic chromium-coated steel plates immersed in an acetic-acetate medium. Samples with flat and rippled walls were immersed at 40, 60, and 80°C. Raman spectroscopy showed the temperature had no effect on acid absorption by the PET coating. The rippled samples had greater amorphousness due to mechanical deformation during manufacturing. Higher temperatures slightly reduced crystallinity near the steel interface but did not compromise the steel plate. The medium increased failures and deterioration of manufacturing defects on the PET surface. A combination of techniques characterized the PET coating's protective capacity on the steel plates.
This document defines terminology related to soil, rock, and contained fluids. It was prepared jointly by the American Society of Civil Engineers and the American Society for Testing and Materials. The standard defines terms found in other standards issued by ASTM Committee D18 on Soil and Rock, including terms related to soil properties, soil classification, hydraulic properties, and aquifer testing.
Mechanical Properties of Concrete with Marine Sand as Partial Replacement of ...IJERA Editor
The process of depleting sources of natural aggregates challenges the production of technically and
environmentally adequate concrete. Alternative material from marine sources is good enough for the
replacement of fine aggregate in the concrete. The material was stockpiled in the open air and no washing,
drying or decontamination process was carried out. Physical and chemical properties of DMS material were
determined. All the materials used in the concrete were selected and tested as per the standard procedures of the
Indian standards. A unique design mix will be done based on the entire material test results. Different mixtures
were produced using DMS in different proportions from 15% to 100% as per the finalized trial of the design
mix. The concrete were submitted to compressive strength testsafter 7, 28 and 90 days of moist curing, as well
as flexure and splitting tensile strength tests for M-25 grade.
IRJET- Evaluation of Water Absorption and Sorptivity Properties of Fly Ash, G...IRJET Journal
1) The document evaluates the water absorption and sorptivity properties of fly ash and GGBS based geopolymer concrete with different volume fractions of glass fibers added.
2) Specimens were tested for water absorption at 30 minutes and 24 hours by measuring their saturated and dry masses. Addition of glass fibers decreased absorption rates compared to control geopolymer concrete.
3) Sorptivity testing involved measuring mass changes of specimens exposed to water over time. Sorptivity values, calculated from the slope of mass change vs square root of time, decreased with glass fiber addition, indicating a denser microstructure with fewer interconnected pores.
This document summarizes a study on the effect of various synthesis parameters on the setting time and workability of fly ash-based geopolymer paste and mortar. Specifically, it examines the effect of alkali content (Na2O/Al2O3 ratio), silica content (SiO2/Al2O3 ratio), and water-to-binder ratio. The study found that initial and final setting time decreased with increasing alkali content and water-to-binder ratio, but increased with increasing silica content. Workability, as measured by flow table tests, also decreased with higher alkali content and water-to-binder ratio. The results provide an understanding of how synthesis parameters influence
Catalyst Synthesis by Solvothermal Process (Ghanekar,Deshmukh)_Prof PN Dange-...Gandhar Ghanekar
Iron molybdate catalyst was synthesized using a solvothermal process for photocatalytic applications. Monoclinic and orthorhombic iron(II) molybdate micro-sized particles were selectively prepared based on pH, temperature, and reaction time. The catalyst has unique 3D architectures and can be used to decompose dyes and other organic contaminants photocatalytically. Parameters like pH, concentration, temperature, and time were optimized to produce the catalyst and for its application in degrading methylene blue dye. The catalyst showed potential for scale-up and other industrial applications.
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Effect of Laser Peening on the life of failure mode of a cold pilger dieLSP Technologies
The laser shock peening (LSP) process was used to impart compressive residual stresses to pilger dies made of A2 tool steel, increasing their life. X-ray diffraction analysis found LSP generated compressive stresses over 1 mm deep in treated dies. An LSP-treated die produced 300% more tubing than standard dies before failure, exhibiting altered failure from crack propagation to plastic deformation and flaking. While pitting from LSP may have influenced earlier cracking, LSP significantly extended die life through deep compressive stresses that impeded crack growth.
1) The document examines the role of various catalysts (HCl, H2SO4, CH3COOH, HF, NH4OH) in the fabrication of silica films using a sol-gel process.
2) It was found that different catalysts can have dramatic effects on the porosity, optical quality, shrinkage, thickness, structural evolution during thermal treatment, and stress of the films. For example, using H2SO4 instead of HCl as the catalyst increased the porosity of thermally treated films from 2.8% to 31%.
3) Experiments were conducted to study the effects of various catalysts on silica films fabricated via spin coating of precursor solutions and subsequent thermal
This study experimentally investigated the effects of Millenium 21 internal curing admixture on the durability and strength of concrete. Compressive strength, carbonation, and water absorption tests were performed on conventionally cured and internally cured concrete specimens at various ages. The results showed that internally cured concrete specimens had higher compressive strength at 7, 28, and 120 days compared to conventionally cured specimens. Carbonation depth was also lower in internally cured specimens at 120 days. Additionally, internally cured specimens exhibited reduced water absorption compared to conventionally cured specimens, indicating improved durability. The findings demonstrate that internal curing with Millenium 21 can enhance long-term strength and durability of concrete.
This study investigated the impact of extended curing time on the polymerization depth of fluoride-containing pit and fissure sealant materials. Specifically, it evaluated the Knoop hardness number (KHN) of the top and bottom surfaces of a conventional pit and fissure sealant and a flowable composite cured for the manufacturers' recommended time of 20 seconds as well as an extended time of 60 seconds. The flowable composite exhibited higher KHN values than the pit and fissure sealant under all curing conditions. An extended curing time of 60 seconds increased the KHN of the bottom surface and bottom/top hardness ratio of the composite but did not significantly impact the sealant. The flowable composite demonstrated
This document provides specifications for broken brick coarse aggregate for use in lime concrete. It outlines:
- The general quality requirements for the broken bricks, including that they must be well-burnt and free of impurities.
- The physical requirements for the aggregate, including specifications for grading, bulk density, impact value, water absorption, and soluble matter content.
- The sampling methods to be used.
It also includes appendices describing the test methods for determining water absorption and soluble matter content of the aggregate.
The document describes a method for fabricating copper-silver (CueAg) core-shell particles with anti-oxidation and antibacterial properties. Tartaric acid is used as a reducing and chelating agent to coat silver nanoparticles onto copper particle cores in an aqueous system. The molar ratios of [TA]/[Ag] and [Ag]/[Cu] influence the formation and uniformity of the silver coatings on the copper particles. CueAg particles prepared with a [TA]/[Ag] ratio of 0.5 and [Ag]/[Cu] ratio of at least 0.2 exhibited a uniform silver coating and significantly reduced copper oxidation when heated. Testing showed the CueAg particles had satisfactory antibacterial
IRJET-Partial Replacement of Cement with Different Additives in ConcreteIRJET Journal
1. The document discusses partial replacement of cement with different additives in concrete such as carbon black powder, calcium sulphate, and rice husk ash. Concrete cubes and cylinders were cast with different percentage replacements to study the effect on properties.
2. Testing showed that using these additives as fillers and desiccants can enhance concrete properties like density, strength, and resistance to atmospheric attack by decreasing pores in the concrete.
3. The optimum percentages of addition of these additives found to improve compressive strength were 2-5% for carbon black and up to 15% for silica fume.
Corrosion studies of colmonoy - 6 in nitric acid during gadolinium removal st...RAMASUBBU VELAYUTHAM
This document summarizes a study on the corrosion of Colmonoy-6, a nickel-based alloy used in valves and bearings of nuclear power plant moderator systems, when exposed to nitric acid conditions present during gadolinium removal from the moderator. Specimens of undiluted Colmonoy-6 deposits and Colmonoy-6 coatings on stainless steel with varying levels of dilution were exposed to a nitric acid solution at 65°C, and corrosion rates were estimated through weight loss and electrochemical measurements. Microstructural analysis found the undiluted deposit and multiple layer coatings contained more carbide and boride precipitates than single layer coatings, indicating lower dilution effects.
Durability Characteristics of Fiber Reinforced Geopolymer Concrete Incorporat...IRJET Journal
This document summarizes a study on the durability characteristics of fiber reinforced geopolymer concrete incorporating fly ash and ground granulated blast furnace slag (GGBS). Tests were conducted to determine the sulfate resistance, chloride resistance, water absorption, and abrasion resistance of the concrete. Various fiber dosages were tested. The results showed that the geopolymer concrete exhibited better durability when exposed to sulfate and chloride environments compared to ordinary Portland cement concrete. The geopolymer concrete also had lower water absorption.
Combination of urea-Sn+2 in SCP solution was examined as a corrosion inhibitor for concrete reinforced steel by potentiodynamicpolarization, surface synergist parameter and cyclic voltammetry methods comparing with urea–Zn+2 combination. A synergism parameter (SI) indicated a synergistic effect between urea and Sn+2was exist. Polarization study revealed that formulation consisting of 300 ppm urea+50 ppm Sn+2 in SCP solution provided inhibition efficiency (IF) of 85.93% while 300 ppm urea +50 ppm Zn+2 provided 82.3% IF, and this combination acts as anodic type inhibitor. Cyclic voltammetry curves showed that the steel samples immersed in this formulation has low tendency to pitting corrosion. From these results it can be concluded that urea – Sn+2 inhibitor formulation is a good corrosion n inhibitor for concrete reinforced steel, it can maintain stable passive film on steel surface even in the presence of aggressive chloride ions so it can be used instead of the high toxicityZn+2 inhibitor to improve the corrosion inhibition of urea fertilizer inhibitor.
Performance of blended corrosion inhibitors for reinforced concreteeSAT Journals
Abstract Use of chemical corrosion inhibitors has been recognized as one of the effective way of controlling rebar corrosion in reinforced cement concrete (RCC). Corrosion inhibiting admixtures fall into the specialty admixture category and are used to slow down corrosion of reinforcing steel in concrete. The addition of corrosion inhibitors to the mix, offers a viable corrosion protection measure. There are generally three groups of inhibitors: anodic, cathodic and mixed inhibitors. The effect of these chemicals on various physical properties of cement such as setting time, pH, and compressive strength needs to be explored before use. In the present investigation an attempt has been made to mix two commercially available corrosion inhibitors and evaluate its effect on setting time, pH and compressive strength. In the next part of the study electrochemical test involving the blended chemical corrosion inhibitor were also conducted on RCC slab specimen. Corrosion kinematic parameters have been estimated using potentio-dynamic polarization tests. It has been observed that the corrosion inhibitor does not have any adverse effect on physical properties of cement and cement concrete. The low corrosion current density exhibited by the inhibitor proves their potential in controlling corrosion initiation and propagation. Keywords - Corrosion inhibitors, setting time, compressive strength, corrosion kinematic parameters
Performance of blended corrosion inhibitors for reinforced concreteeSAT Publishing House
This document discusses the performance of blended corrosion inhibitors for reinforced concrete. It summarizes the results of experiments conducted to evaluate the effect of a blend of calcium nitrite and calcium hypophosphite corrosion inhibitors on the physical properties and corrosion resistance of cement and concrete. The experiments found that the corrosion inhibitor blend did not adversely affect the setting time, pH, or compressive strength of cement or concrete. Electrochemical tests also showed that the corrosion inhibitor blend reduced the corrosion current density, demonstrating its potential to control corrosion initiation and propagation in reinforced concrete.
Analyzing Adhesion of Epoxy/Steel Interlayer in Scratch TestIJERA Editor
The document summarizes a study that investigated how different parameters affect the adhesion strength of epoxy adhesives bonded to zinc-plated mild steel. Scratch tests were performed using two epoxy adhesives and zinc-plated mild steel adherends treated with different surface treatments. A Taguchi experimental design was used to test combinations of surface treatment, adhesive type, blade angle, and adhesive thickness. Results found that surface treatment and thickness were the most influential parameters, affecting scratch force by 52.4% and 19.9% respectively, and scratch energy by 44.0% and 25.6% respectively.
The document summarizes research on the erosion-corrosion behavior of WC-Co-Cr cermet coatings applied by thermal spraying. Experiments were conducted exposing the coatings to a liquid-solid jet of 3.5% NaCl solution with silica sand loadings of 200 and 500 mg/l. Electrochemical measurements and surface analysis using SEM were used to understand the corrosion and erosion damage mechanisms. Cathodic protection was applied to isolate the erosion effects. The results showed the WC-Co-Cr coating had higher resistance to erosion-corrosion compared to stainless steel controls. Microstructural characterization revealed the coating had a lamellar structure and composition of WC-12% Co-6% Cr with
Measurements of Geophysical Velocity for Building InspectionAli Osman Öncel
The document describes a study that evaluated the compressive strength of concrete using nondestructive testing methods. Specifically, it used the rebound hammer test, ultrasonic pulse velocity test, and a combined method that uses both. Statistical analysis, including simple and multiple linear regression, was used to develop correlations between the nondestructive test results and actual compressive strengths from cylinder and core samples. The combined method was found to improve the accuracy of estimating compressive strength by taking into account factors that influence each test method differently. Equations derived from the statistical analysis can be used to predict compressive strength on site based on rebound hammer and ultrasonic pulse velocity measurements.
This document discusses the gamma ray shielding and structural properties of PbO-BaO-P2O5 glass systems. Transparent glass samples were prepared with compositions of 55PbOxBaO(45-x)P2O5 (x = 1 to 5). Gamma ray shielding properties like mass attenuation coefficient and half value layer were calculated and compared to standard radiation shielding concrete. Characterization techniques like density, XRD, FTIR, Raman, UV-visible were used to study the structural properties and understand how the structure changes with the addition of BaO. The glass system showed improved gamma ray shielding with increasing BaO content and has potential to be a viable alternative to conventional concrete radiation shields
Combination Of The Non-Destructive Methods For Evaluating The Quality Of Conc...IJERA Editor
The study is aboutthe use and comparison of three non-destructive methods (dynamic auscultation, sclerometric auscultation and auscultation by RADAR (Radio Detecting and Ranging) to monitor and assess the quality of concrete. Samples of reinforced concrete panels, dimensions 200x100x30 cm of concrete dosed at 350 kg/m3 with diverse E/C ratio were achieved, conserved in the laboratory and subjected to various non-destructive test. The synthesis of the results obtained by auscultation RADAR shows a decrease in the propagation speed of the electromagnetic wave with an increase of the E/C ratio and a decrease in resistance of concrete values measured and confirmed by other non-destructive techniques (sclerometric and dynamic auscultations). This shows that more the dielectric constant is high, morethe concrete resistance is reduced, and conversely the opposite.
Electrochemical impedance spectroscopy (EIS) is a technique used to characterize coated metals and monitor the degradation of coatings over time. EIS involves applying an AC voltage to a coated metal sample immersed in an electrolyte and measuring the impedance over a range of frequencies. Changes in impedance parameters such as coating capacitance, pore resistance, and polarization resistance can provide information about the coating's condition and failure processes. EIS is able to detect coating deterioration earlier and more sensitively than traditional tests like salt spray testing. It generates quantitative data to evaluate coatings and optimize formulations while reducing testing time compared to other techniques.
This document discusses using acoustic emission (AE) techniques to non-destructively evaluate the properties of concrete and mortar, including compressive strength, flexural strength, and moisture content. Tests were conducted on concrete cubes and mortar cubes and beams with varying water-to-cement ratios. Results showed that the AE amplitude attenuated with increasing distance from the source, and that the attenuation factor correlated strongly with compressive strength, flexural strength, and moisture content - providing a way to predict these properties using a non-destructive AE method.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This document summarizes research using electrochemical impedance spectroscopy (EIS) to evaluate the protective properties of paint coatings on two bridges. EIS measurements were taken in the laboratory and in situ on the bridges. The results showed:
1) EIS provided information about coating properties like resistance, capacitance, and barrier effectiveness.
2) Coatings on external bridge surfaces exhibited high impedance and barrier properties. Coatings on internal surfaces showed signs of water penetration over time.
3) In situ bridge coating measurements correlated well with laboratory coating measurements, indicating EIS can effectively evaluate coatings on structures.
HVOF Sprayed WC-Cocr Coating on Mild Steel: Microstructure and Wear Evaluationiosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Creep is defined as the plastic deformation under sustain load. Creep strain depends
primarily on the duration of sustained loading. It has been widely acknowledged that creep of
concrete is greatly influenced by the surrounding ambient. Creep induces the deflection of the
structural member with time. Hence the study on creep of concrete is necessary to prevent failure. A
concrete cylinder is casted for two different grades and the load of 40% of its compressive strength
is applied constantly. Creep is measured with time. A time - dependent creep is provided in a graph
showing its variation.
This document discusses various methods for evaluating the effectiveness of corrosion inhibitors, including wheel tests, bubble tests, static tests, and rotating electrode methods. Key evaluation steps include laboratory testing under simulated field conditions to screen inhibitors, evaluating compatibility factors like cost and environmental impact, and final field testing. Laboratory tests measure corrosion rates through weight loss or electrochemical techniques. Rotating electrode methods like the rotating cylinder electrode can model turbulent flow conditions and are well-suited for studying corrosion under pressure and temperature. The document also provides examples of corrosion inhibitor formulations and testing methods.
Corrosion Inhibition of Carbon Steel In Sulfuric Acid by Sodium CaprylateIJERA Editor
The interaction of a sodium salt of octanoic acid, sodium caprylate (SC), with a carbon steel (CS) surface was
investigated, using range of experimental techniques. It was shown that SC acts as a good CS general corrosion
inhibitor, yielding a maximum corrosion inhibition efficiency of 77%. This high inhibition efficiency is
maintained even at higher temperatures. It was determined that SC inhibits both partial corrosion reactions, and
can thus be considered to be a mixed-type inhibitor. The adsorption of SC on the CS surface was described by
the Langmuir adsorption isotherm. It was found that this process is spontaneous, irreversible and driven by the
entropy gain. The CS surface morphology was studied by SEM and it was demonstrated that SC is a very
effective general corrosion inhibitor of CS. This also was confirmed by contact angle measurements which
showed that the CS surface became more hydrophobic when the SC was added to the solution.
Corrosion Inhibition of Carbon Steel In Sulfuric Acid by Sodium CaprylateIJERA Editor
The interaction of a sodium salt of octanoic acid, sodium caprylate (SC), with a carbon steel (CS) surface was
investigated, using range of experimental techniques. It was shown that SC acts as a good CS general corrosion
inhibitor, yielding a maximum corrosion inhibition efficiency of 77%. This high inhibition efficiency is
maintained even at higher temperatures. It was determined that SC inhibits both partial corrosion reactions, and
can thus be considered to be a mixed-type inhibitor. The adsorption of SC on the CS surface was described by
the Langmuir adsorption isotherm. It was found that this process is spontaneous, irreversible and driven by the
entropy gain. The CS surface morphology was studied by SEM and it was demonstrated that SC is a very
effective general corrosion inhibitor of CS. This also was confirmed by contact angle measurements which
showed that the CS surface became more hydrophobic when the SC was added to the solution.
Presentation: Comparative Evaluation Of Epoxy Treated Reinforcement And Ename...IEI GSC
Presentation on Comparative Evaluation Of Epoxy Treated Reinforcement And Enamel Treated Reinforcement made by Dr PK Parhi, Professor of Civil Engineering, College of Engineering & Technology, Bhubaneswar at #33NCCE 33rd National Convention of Civil Engineers at #IEIGSC , Ahmedabad
A Review on Recent Trends in Non Destructive Testing Applicationsvivatechijri
The field of NDT is a very large and interdisciplinary field that plays a critical role in inspection of
crucial component. These test may fail due to either the fault in the equipment used, the miss application of the
methods or the However, these techniques generally require considerable operator skill and interpreting test
results. This paper presents the reviews of different works in the area of NDT and tries to find out recent and
trends available in industries and other fields in order to minimize the total equipment cost, minimize damages
and maximize the safety of machines, structures and materials
The document describes an experiment to determine how corrosion affects the geometric characteristics and theoretical ultimate load-capacity of steel samples. Steel samples were subjected to accelerated electrochemical corrosion in cycles and measured after each cycle. The corrosion caused a non-linear decrease in diameter along the sample length. Theoretical calculations using these geometric data showed that while corrosion caused a slight decrease, it significantly reduced the ultimate load-capacity. The results provide insight into how corrosion progressively impacts steel strength over time.
Taguchi analysis of single layer CrN coatings on AISI 304 Stainless Steel to ...IJAEMSJORNAL
This document summarizes a study investigating the erosive corrosive wear behavior of single layer chromium nitride (CrN) coatings on AISI 304 stainless steel samples. Taguchi analysis was used to test coated and uncoated samples under varying impact velocity, impingement angle, and erodent discharge. The results showed that CrN coatings reduced the wear rate by nearly 2 times compared to uncoated samples. Taguchi analysis identified that among coated samples, erodent discharge was the most significant factor affecting wear rate, followed by coating thickness and impingement angle, with impact velocity being the least significant. For uncoated samples, impact velocity was the most significant factor. The optimum parameters for minimum wear rate
O documento descreve a evolução da empresa italiana Fira Industriale ao longo de mais de 60 anos, desde sua fundação como uma empresa artesanal até se tornar um produtor líder mundial de rodas para veículos agrícolas e industriais. A empresa sempre se manteve fiel à produção de rodas de aço, apesar de adaptar seus processos e equipamentos às mudanças do mercado. Recentemente, a Fira Industriale investiu em um novo sistema de pré-tratamento e pintura por cataforese para melhorar a qualidade e eficiência da pint
La empresa Saro de España ha obtenido la homologación Qualisteelcoat para sus ciclos de pintura, siendo la primera en la península ibérica en lograr esta clasificación CM5. Para lograr esto, realizó inversiones tecnológicas para actualizar su línea de pretratamiento, incluyendo un nuevo proceso basado en nanotecnología desarrollado por Proquimia. Este nuevo proceso les permitió cumplir con los estándares para la nueva certificación.
Dollmar S.p.A. is an Italian chemical company that produces nanotechnology-based pretreatments under the Dollcoat brand for various metal substrates. It has several subsidiaries and partnerships involved in chemical storage and distribution. The document describes Dollmar's main pretreatment products - Dollcoat SA 115, SA 119, SA 121, and SA 113. SA 115 is a multimetal nanotechnology-based passivation. SA 119 is a chrome-free passivation for hot-dip galvanized steel. SA 121 is a chrome-free, QUALICOAT-approved conversion coating for aluminum. SA 113 provides an easy-to-clean surface with low adhesion to inks, paints
1. Technical Paper
Anticorrosive test
The fast lane to failure
Cyclic impedance test gives rapid characterisation of coating breakdown
* Corresponding author: José Javier Gracenea* useful technique here [1-8], although long periods are
José Javier Gracenea Maria José Gimeno needed (days, weeks and sometimes months) to per-
Mediciones y Corrosión SL Julio José Suay form this type of test and obtain good results.
+ 34 964 387-389
josejgracenea@medco.es
Two different tests of anticorrosive properties (salt Combined AC/DC impedance
fog spray and a cyclic impedance test called ACET)
have been used to evaluate two-layer coating
test gives fast results
systems for aeronautical application and establish Hollaender et al. [9-11] developed a rapid method for
a correlation between them. The ACET technique testing coated metals in food packaging, consisting of
provides good correlation to salt spray, faster a combination of DC and AC measurements (the AC/DC/
evaluation and more details of the mode of coating AC procedure) which has been successfully adapted and
breakdown. used in liquid paints applied to steel substrates [12-14].
After an initial AC measurement, the test sample is sub-
P
rediction of the anticorrosive properties of paints jected for a short time to a constant cathodic voltage (DC)
is one of the most important lines of research in producing a stress on the sample and, following that, an
organic coatings. Due to the complexity of the cor- AC spectrum is recorded again.
rosion and degradation processes in organic-metal sys- The change in the characteristics of the impedance spec-
tems, the main routines for assessing interactions and trum can be attributed to coating deterioration (pore for-
materials have been developed experimentally by us- mation) and a delamination process in the metallic sur-
ing different exposure processes and techniques for the face due to hydrogen and OH- production (if a cathodic
measurement of properties. reaction takes place).
The main types of exposure process are accelerated The new ACET (Accelerated Cyclic Electrochemical Tech-
ageing tests (e.g. salt fog spray) and natural exposure nique) procedure developed by Medco [15-19] is based
experiments (which must be planned for long durations on the Hollaender method but incorporates two principal
and are very expensive to run). innovations. First, a long potential relaxation period was
Salt fog spray is one of the longest-established evaluation introduced after the polarisation, where the potential and
techniques for which different international standards intensity are recorded against time, data that is used to
(ISO 9227, ASTM B117) have been developed. Neverthe- evaluate the adhesion of the coatings to the substrate.
less, this technique is very subjective and does not give Second, new numerical methods were developed to
quantitative information about the corrosion processes or establish correlations between ACET and traditional salt
an interpretation of the overall process itself. spray resistance results.
It is still necessary to develop techniques to measure the In this work ACET and salt fog spray were used to study
anticorrosive properties in a direct sense, thus various the anticorrosive properties of the paint systems de-
electrochemical techniques have been used to evalu- scribed below. The validity of the new technique has
ate the protective performance of organic coating/metal also been examined as a useful method for determining
systems. The application of electrochemical impedance the anticorrosive properties of paints in very short times,
spectroscopy (EIS) to coated metals has proved to be a comparing it with other different evaluation procedures
(EIS and salt fog spray).
Coating systems and test procedures
Two epoxy-polyurethane two-coat systems were chosen
for the comparative tests. Both systems were solvent-
based, with a high solids epoxy primer containing Cr(VI)
anticorrosive pigments. The samples were cured at room
temperature for 21 days. The total thickness of the paint
systems was in the range 50-60 µm.
The accelerated salt fog spray test was performed in
accordance with ASTM B 117-85/ISO 9227. In this test a
“Anticorrosive cross is cut along the coating through to the bare metal.
Coatings” Samples are collected after different periods of time in
Jörg Sander the test and evaluated up to a maximum of 3000 hours
www.european- exposure.
coatings.com/books After each collection, the samples were dried; blister-
Figure 1: Representation of the ACET test schedule ing, corrosion and delamination were measured after
84 European Coatings J OURNAL 03 l 2011 www.european-coatings.com
2. Technical Paper
Anticorrosive test
24 hours of ambient relaxation time. Delamination was presence of the electrolyte, with production of iron ox-
evaluated after applying 30 mm wide tape to one arm of ides and hydroxides.
the cross and peeling off the paint with it. On the other hand, the forced polarisation means that
The ACET procedure (Figure 1) is based on the applica- the double layer in the interface is disturbed and needs
tion of a stress (cathodic polarisation) to a coated sample, to be reorganised, which is reflected in the variation of
then measuring the impedance (EIS) of the system after the potential at the relaxation process. At the same time,
it. This stress/impedance sequence is repeated several the different ions inside the coating will leave it, produc-
times until the system is substantially damaged. In order ing charge equilibration and reorganisation of the poly-
to obtain more information about the coating itself and meric molecule dipoles, also producing a variation in the
the whole system, a depolarisation step can be included potential.
for a given period (relaxation time). Thus the system is degraded by the loss of adhesion
An initial EIS measurement gives an idea of the imped- (formation of H2), the pore opening by the incoming of
ance of the system (using Bode plots and modelled char- the different species from the electrolyte, and the forma-
acteristic parameters and the cycle shown in Figure 1). tion of corrosion products by electrochemical processes.
These processes can be followed by the results obtained
Underlying corrosion in the relaxation process.
theory summarised
A cathodic reaction of water hydrolysis occurs
when the potential is more negative than -1.0
V relative to a saturated calomel electrode [27]. EXCELLENCE FOR YOUR PLANT
The test technique is based on the influence
that this has on coating adhesion because of
the formation of H2 (gas) and OH-. The evolution
of H2 will increase local delamination (Figure 2)
giving rise to the failure of the coating system
(reflected in the variation of the impedance).
When the cathodic reaction stops and H2 pro-
duction has taken place, the normal electro-
chemical corrosion of the system occurs in the
Results at a glance
Although the neutral salt spray test has
been established for many year in evalu-
ating anticorrosive behaviour, it gives no Complete plant for the
production of water base
information on the underlying corrosion paints and additives
processes, and testing times for high per-
formance coatings can be quite long.
COMEC has been producing machines and systems for the chemical
An alternative process known as ACET and paint industry for over 35 years, designing specific solutions for all
(Accelerated Cyclic Electrochemical Tech- customer needs.
nique) has been developed, which produces The only STANDARD way: QUALITY first!
very rapid breakdown of coatings under Comec machines manage every step of the production process:
cathodic polarisation and also provides raw materials and additives STORING and DOSING, MIXING, GRINDING,
some information on different modes of FILTERING, PAINT METERING, PACKING and PALLETIZING.
coatings failure.
COMEC offers the best safety level guarantee for
A comparison between two polyurethane
inflammable products processing.
coating systems showed a good correlation
SYSTEMS AND MACHINES CERTIFIED FOR ZONE 0
between salt spray and ACET test cycles.
Ex II 1/2 Gc II B T4 mark in accordance with the
The time required for the evaluation was
certificate issued by notified body ICEPI 06 ATEX 03C021
3000 hours in the salt spray but less than
24 hours in the ACET test.
In the cases studied, poor salt spray be-
haviour is correlated with a strong change HALL 6 - STAND 253
in the impedance value at low frequencies
during the ACET test cycles. www.comecsrl.it
www.european-coatings.com 03 l 2011 European Coatings J OURNAL 85
3. Technical Paper
Anticorrosive test
the left, where it can be seen that the impedance varia-
tion is smaller than in the plot on the other side.
In order to understand these figures, it is necessary to
look at the theoretical basis underlying this ACET meth-
od. The cathodic polarisation applied to the coated metal
can cause two processes to occur in the paint.
Firstly, the introduction and passage of different cations
(H+, Na+, and so on) from the electrolyte through the
paint due to the negative potential imposed in the me-
tallic substrate. This can produce a concentration of posi-
tive charges in the coating that must be neutralised by
a balancing entry of anions (like Cl-) The passage of ions
(which can also be hydrated) through the coating can
cause its deterioration and the formation of pores.
Secondly, the cathodic reaction that can take place in the
metallic surface depending on the level of negative po-
larisation and the type of electrolyte [27] is shown in this
Equation:
2H2 O (l) + 2e - → H2 (g) + 2 OH – (1)
Figure 2: Processes occurring during the ACET test schedule The cathodic reaction will take place first if the elec-
trolyte is able to pass through the coating and reaches
the interface. This depends on the properties of the film
(permeability to ions, adhesion to substrate, existence
The ACET procedure measures the quality of the coat- of local film delamination, susceptibility of the coating
ing and its adhesion through the study of the resistance to form cracks because of its high rigidity, etc.) and, of
that the system offers to its degradation by the cathodic course, the applied cathodic voltage.
polarisations. In this study the cathodic polarisation was Obviously, the higher the quality of the primer (low per-
carried out for 20 minutes at a constant voltage of -4 V. meability and high ductility) the lower will be the prob-
Following that, the relaxation time was for 3 hours, and ability of the electrolyte reaching the interface, and of
finally an EIS was applied under the stated conditions the cathodic reaction taking place. The deterioration of
. The test sequence was repeated six times (around the coating due to cathodic polarisation can be caused
24 hours of testing) and was fully automated in Zahner primarily by the film delamination process at the metallic
equipment. interface produced by the cathodic reaction (evolution of
H2), although the passage of ions can also exert a de-
Results evaluated in terms grading effect.
of cathodic reactions Relaxation potential reveals
The ACET test was carried out on aeronautical epoxy-
details of film breakdown
polyurethane systems. Figure 3 shows the Bode plots If it is possible to detect whether the cathodic reactions
of these coatings, EP-PU1 (left) and EP-PU2 (right). The have taken place during polarisation, this information
worst behaviour is seen on the right-hand side. could be used to learn a little more about the perform-
This is characterised by a strong change in the impedance ance and quality of the paint. One possible way of de-
value at low frequencies during the cycles of the ACET tecting the existence of H2 (g) and OH- production (lead-
technique. Systems with better responses are shown on ing to more delamination) at the interface is to study the
evolution of the open circuit potential after polarisation
Figure 3: Bode
plots for aeronauti-
cal epoxy-poly-
urethane systems,
EP-PU1 (left) and
EP-PU2 (right);
paramters: ACET:
-4 V, 20 min, 25
min EIS, 3 h relax
86 European Coatings J OURNAL 03 l 2011 www.european-coatings.com
4. new paint,
no pain.
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5. Technical Paper
Anticorrosive test
Figure 4: Relaxation
plots for aeronauti-
cal epoxy-poly-
urethane systems
EP-PU1 (left) and
EP-PU2 (right); pa-
rameter: ACET: -4 V,
20 min, 25 min EIS,
3 h relax
the poor quality of the coating. Probably if longer relaxa-
Figure 5: Neutral tion times were used, new relaxation processes could be
salt spray test observed.
results showing The relaxation time will give an idea of the evolution with
good performance time of the system after the applied stress until it again
of EP-PU1 (left) and reaches the steady state (graphics Erelaxation = f(time)).
severe blistering Figure 5 shows salt fog spray test results. The system
of EP-PU2 system EP-PU1 (left) achieved 3000 h of exposure while EP-PU2
(right) after 3000 (right) was damaged by blistering. Thus, it is clear that a
hours correlation exists in this case between the established
salt fog test and the much faster ACET procedure.
(during the relaxation time). When cathodic polarisation REFERENCES
is stopped the coated metal potential will relax showing
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In the first case, if cathodic reactions were taking place [2] Bierwagen G. P., Jnl. Coat. Tech., 1992, Vol 64, pp 71ff.
(H2 production), the potential would have a quick relax- [3] Liu B. et al, Acta Physico-Chimica Sinica, 2001, Vol 17, pp 241ff.
ation, normally around -1 V [27] (with small variations [4] Skerry B. S., Chen C-T., Ray C.J., Jnl. Coat. Tech., 1992, Vol 64, pp 77ff.
depending on the coating), which corresponds to the [5] Gwori S., Balakrishnan K., Prog. Org. Coat., 1994, Vol 23, pp 363ff.
termination of the reaction and, afterwards, a second re- [6] Selvaraj M., Guruviah S., Prog. Org. Coat., 1996, Vol 28, pp 271 ff.
laxation that corresponds to ions and electrolyte leaving [7] Hernández L. S., del Amo B., Romagnoli R., Anti-Corrosion Methods
the coating and possibly the formation of a new double and Materials, 1999, Vol 46, pp 198ff.
layer in the metallic surface. [8] Liu X. et al, Materials and Corrosion, 1995, Vol 46, pp 33ff.
In any case, the cathodic reaction will produce the entry [9] Hollaender J., Ludwig E., Hillebrand S., Proc. 5th International
of electrolyte through the coating and the production of Tinplate Conference, London, 1992, pp 300ff.
H2 (g) and OH- at the metal/coating interface. The time [10] Hollaender J., Schiller C. A., Strunz W., Food additives and contami-
needed for this electrolyte and the ions to leave the nants, 1999, Vol 14, No. 6-7, pp 617ff.
film will therefore be higher because they have to pass [11] Hollaender J., Schiller C.A., Strunz W., Proc. EIS 2001, Marilleva-
through the entire primer film. Italy, 2001.
Alternatively, if no cathodic reactions have taken place, [12] Rodriguez M.T. et al, Prog. Org. Coat., 2004, Vol 50, pp 68ff.
there would be a single relaxation process that corre- [13] Suay J. J. et al, Prog. Org. Coat., 2003, Vol 46, pp 121ff.
sponds to ions and electrolyte leaving the primer or to [14] Rodriguez M.T. et al, Prog. Org. Coat., 2004, Vol 50, pp 123ff.
the reconfiguration of the polymer dipoles. This relaxa- [15] García S. J., Suay J., Prog. Org. Coat., XX (2009), Prog. Org. Coat. 66
tion will take place over longer times as ions and electro- (2009), p. 306.
lyte penetrate deeper into the film, but they will probably [16] García S. J., Suay J., Prog. Org. Coat., 2007, Vol 59, pp 251-258.
need less time than in the first case described above. [17] García J. et al, Prog. Org. Coat., 2007, Vol 60, pp 303-311.
Figure 4 shows the potential relaxation versus time of the [18] García S. J., Suay J., Prog. Org. Coat., 2006, Vol 57, pp 273–281.
different epoxy-polyurethane systems after five cathodic [19] Rodriguez M. T. et al, Prog. Org. Coat., 2004, Vol 50, pp 123-131.
polarisations. The sample EP-PU1 with the best behav- [20] Lee S. S. et al, Prog. Org. Coat., 1999, Vol 36, pp 79ff.
iour shows only one relaxation at high potential which [21] Mansfeld F., Electrochim. Acta, 1993, Vol 38, No 14, pp 1891-1897.
indicates that during the cathodic polarisation there was [22] Amirudin A., Thierry D., Prog. Org. Coat., 1995, Vol 26., pp. 1-28.
no hydrogen production because of its good anticorro- [23] Walter, G. W. J.nl. Electroanal. Chem., 1981, Vol 118, pp 259-273.
sive properties (low permeability and high adhesion). [24] Walter, G. W.,Corros. Sci., 1986, Vol 26, No 9, pp 681-703.
The sample EP-PU2 shows a relaxation at -1 V that cor- [25] Gamry Instruments, “Electrochemical Impedance Spectroscopy
responds to the ending of hydrogen production, because Primer”, www.gamry.com.
the cathodic reaction of electrolysis could take place due [26] Tang, N., Ooij W. J., Górecki G., Prog. Org. Coat., 1997, Vol 30, pp 255ff.
to the presence of water in the interface as a result of [27] Leidheiser H., Jnl. Adhesion Sci. Tech., 1987, Vol 1, pp 79ff.
88 European Coatings J OURNAL 03 l 2011 www.european-coatings.com
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Fillers for Paints
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