The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Olivie Gabe - One of the best experts on this subject based on the ideXlab platform.
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influence of the surface properties of concrete on the Adhesion of Coating characterization of the interface by peel test and ft ir spectroscopy
Progress in Organic Coatings, 2011Co-Authors: Matthieu Horgnies, Pierre Willieme, Olivie GabeAbstract:Abstract The understanding of the Adhesion between protective Coating and concrete is essential to ensure the aesthetic of buildings. Polyurea (PU) based Coating are mainly deposited on the surface of concrete, several days after demoulding. However, their Adhesion on concrete depends on different interlinked parameters. This study is based on the development of specific peel tests. A strengthened and porous membrane is introduced into the layer of liquid Coating before its crosslinking. This methodology ensures a reproducible debonding of the Coating/concrete system to measure the fracture energy. The fracture loci are then characterized by Fourier Transformed Infra-Red (FT-IR) spectroscopy. Results show that humid conditions of curing and long-term ageing strongly decrease the Adhesion of Coating. This weak Adhesion is related to the presence of large crystals of portlandite, the growth of efflorescence or the kinetics of carbonation that could close the porosity or induce a weak interface. The type of the mould is also significant because it could induce the tearing of the extreme surface of concrete during demoulding. This tearing increases the roughness and the open porosity that enhances the fracture energy. Finally, this study demonstrates that the Adhesion of PU Coating is mainly conditioned by the mechanical anchorage at the surface of concrete.
Matthieu Horgnies - One of the best experts on this subject based on the ideXlab platform.
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influence of the surface properties of concrete on the Adhesion of Coating characterization of the interface by peel test and ft ir spectroscopy
Progress in Organic Coatings, 2011Co-Authors: Matthieu Horgnies, Pierre Willieme, Olivie GabeAbstract:Abstract The understanding of the Adhesion between protective Coating and concrete is essential to ensure the aesthetic of buildings. Polyurea (PU) based Coating are mainly deposited on the surface of concrete, several days after demoulding. However, their Adhesion on concrete depends on different interlinked parameters. This study is based on the development of specific peel tests. A strengthened and porous membrane is introduced into the layer of liquid Coating before its crosslinking. This methodology ensures a reproducible debonding of the Coating/concrete system to measure the fracture energy. The fracture loci are then characterized by Fourier Transformed Infra-Red (FT-IR) spectroscopy. Results show that humid conditions of curing and long-term ageing strongly decrease the Adhesion of Coating. This weak Adhesion is related to the presence of large crystals of portlandite, the growth of efflorescence or the kinetics of carbonation that could close the porosity or induce a weak interface. The type of the mould is also significant because it could induce the tearing of the extreme surface of concrete during demoulding. This tearing increases the roughness and the open porosity that enhances the fracture energy. Finally, this study demonstrates that the Adhesion of PU Coating is mainly conditioned by the mechanical anchorage at the surface of concrete.
Pierre Willieme - One of the best experts on this subject based on the ideXlab platform.
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influence of the surface properties of concrete on the Adhesion of Coating characterization of the interface by peel test and ft ir spectroscopy
Progress in Organic Coatings, 2011Co-Authors: Matthieu Horgnies, Pierre Willieme, Olivie GabeAbstract:Abstract The understanding of the Adhesion between protective Coating and concrete is essential to ensure the aesthetic of buildings. Polyurea (PU) based Coating are mainly deposited on the surface of concrete, several days after demoulding. However, their Adhesion on concrete depends on different interlinked parameters. This study is based on the development of specific peel tests. A strengthened and porous membrane is introduced into the layer of liquid Coating before its crosslinking. This methodology ensures a reproducible debonding of the Coating/concrete system to measure the fracture energy. The fracture loci are then characterized by Fourier Transformed Infra-Red (FT-IR) spectroscopy. Results show that humid conditions of curing and long-term ageing strongly decrease the Adhesion of Coating. This weak Adhesion is related to the presence of large crystals of portlandite, the growth of efflorescence or the kinetics of carbonation that could close the porosity or induce a weak interface. The type of the mould is also significant because it could induce the tearing of the extreme surface of concrete during demoulding. This tearing increases the roughness and the open porosity that enhances the fracture energy. Finally, this study demonstrates that the Adhesion of PU Coating is mainly conditioned by the mechanical anchorage at the surface of concrete.
R Elansezhian - One of the best experts on this subject based on the ideXlab platform.
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effect of different pretreatments and heat treatment on wear properties of electroless ni b Coatings on 7075 t6 aluminum alloy
Procedia Engineering, 2014Co-Authors: M Vijayanand, R ElansezhianAbstract:Abstract The effect of various pretreatments on wear behavior of electroless nickel - boron (ENi-B) deposits obtained from a thallium free bath of nickel chloride as source of nickel is presented in this paper. For any quality Coating pretreatment is required. The Adhesion of Coating significantly depends on the pretreatment. Hence in the present investigations five different pretreatments such as zincate (Zn), Ni strike 1 (Ni 1) and Ni strike 2 (Ni 2), absorbed hypophosphite layer (AHL) and Palladium strike (PD) were given to the substrate prior to the ENi-B Coating and their corresponding wear properties were examined. The quality of Coatings with and without heat treatments was estimated by pin on disc wear test method as per ASTM G99 standard. The surface morphology of the coated samples were examined by scanning electron microscope (SEM). The structural characterization of the coated samples was examined by X- ray diffraction (XRD) technique. The results obtained indicated that the wear resistance of the ENi-B deposits were significantly influenced by the pretreatment conditions. Among the five different pretreatments, AHL provided better Adhesion of Coatings over the aluminum alloy. The quality of pretreatments with respect to wear and coefficient of friction are rated as follows: AHL > PD > Ni 2 > Zn > Ni 1. AHL pretreatment significantly improved the wear resistance and decreased the average coefficient of friction. Further to know the influence of heat treatment on wear behaviour of coated samples, the samples were heated at 400° C. It was found that heat treatment improved the wear resistance from ∼ 30 μm to ∼ -70 μm. After heat treatment the average coefficient of friction of AHL samples decreased from 0.079 to 0.009. The complete experimental results and analysis are reported in main paper.
M Vijayanand - One of the best experts on this subject based on the ideXlab platform.
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effect of different pretreatments and heat treatment on wear properties of electroless ni b Coatings on 7075 t6 aluminum alloy
Procedia Engineering, 2014Co-Authors: M Vijayanand, R ElansezhianAbstract:Abstract The effect of various pretreatments on wear behavior of electroless nickel - boron (ENi-B) deposits obtained from a thallium free bath of nickel chloride as source of nickel is presented in this paper. For any quality Coating pretreatment is required. The Adhesion of Coating significantly depends on the pretreatment. Hence in the present investigations five different pretreatments such as zincate (Zn), Ni strike 1 (Ni 1) and Ni strike 2 (Ni 2), absorbed hypophosphite layer (AHL) and Palladium strike (PD) were given to the substrate prior to the ENi-B Coating and their corresponding wear properties were examined. The quality of Coatings with and without heat treatments was estimated by pin on disc wear test method as per ASTM G99 standard. The surface morphology of the coated samples were examined by scanning electron microscope (SEM). The structural characterization of the coated samples was examined by X- ray diffraction (XRD) technique. The results obtained indicated that the wear resistance of the ENi-B deposits were significantly influenced by the pretreatment conditions. Among the five different pretreatments, AHL provided better Adhesion of Coatings over the aluminum alloy. The quality of pretreatments with respect to wear and coefficient of friction are rated as follows: AHL > PD > Ni 2 > Zn > Ni 1. AHL pretreatment significantly improved the wear resistance and decreased the average coefficient of friction. Further to know the influence of heat treatment on wear behaviour of coated samples, the samples were heated at 400° C. It was found that heat treatment improved the wear resistance from ∼ 30 μm to ∼ -70 μm. After heat treatment the average coefficient of friction of AHL samples decreased from 0.079 to 0.009. The complete experimental results and analysis are reported in main paper.
