The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Lihui Xue - One of the best experts on this subject based on the ideXlab platform.
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effect of ultraviolet aging on rheology chemistry and morphology of ultraviolet absorber modified Bitumen
Materials and Structures, 2013Co-Authors: Zhengang Feng, Henglong Zhang, Dongliang Kuang, Lihui XueAbstract:Seeking a new method to solve the ultraviolet (UV) aging of Bitumen is of great importance for road applications since the UV aging is considered to be one of the main causes leading to the performance deterioration of Bitumen. In this paper, two UV absorbers (octabenzone and bumetrizole) were applied to modify the Bitumen by melt blending. Effect of UV aging on rheology, chemistry and morphology of the UV absorber modified Bitumens was investigated, by means of dynamic shear rheometer, thin-layer chromatography with flame ionization detection, Fourier transform infrared spectroscopy and atomic force microscopy, to reveal the mechanisms of action for Bitumen and UV absorbers. Results show that the two UV absorbers show opposite influences on the UV aging performance of Bitumen depending on the type of UV absorbers. The bumetrizole improves the UV aging resistance of Bitumen remarkably since the bumetrizole can inhibit reactions of aromatization and oxidation of Bitumen molecules to a certain extent during the UV aging, and thus slows down the rate at which the Bitumen transforms from sol to gel. The bumetrizole modified Bitumen has the potential to be used in pavement for improvement of the UV aging resistance during service life.
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effect of expanded vermiculite on microstructures and aging properties of styrene butadiene styrene copolymer modified Bitumen
Construction and Building Materials, 2013Co-Authors: Henglong Zhang, Xiaojua Jia, Lihui XueAbstract:Abstract Organic expanded vermiculites (OEVMTs) were prepared using cetyltrimethyl ammonium bromide (CTAB) and octadecyl dimethyl benzyl ammonium chloride (ODBA) as intercalation agents. Effect of EVMT organic modification on physical and aging properties of styrene–butadiene–styrene (SBS) modified Bitumen was investigated. The microstructures of the binders were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. EVMT/SBS modified Bitumen forms a phase-separated structure, while OEVMT/SBS modified Bitumens form the exfoliated nanostructures according to XRD analysis. OEVMTs show the more obvious influence on physical properties of SBS modified Bitumen in comparison with EVMT. The compatibility between the EVMT and SBS modified Bitumen is also improved after organic modification of EVMT. AFM analysis indicates that the contrast between the dispersed phase and the matrix phase in SBS modified Bitumen increases with the addition of ODBA-EVMT. As a result of thin film oven test (TFOT), the viscosity aging index of SBS modified Bitumen decreases, while the retained ductility and penetration increase obviously with the introduction of EVMT and OEVMTs. ODBA-EVMT/SBS modified Bitumen has more pronounced improvements in aging resistance of SBS modified Bitumen in comparison with CTAB-EVMT/SBS modified Bitumen by preventing the phase-separated trend of the SBS modified Bitumen during TFOT.
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Effect of expanded vermiculite on microstructures and aging properties of styrene–butadiene–styrene copolymer modified Bitumen
Construction and Building Materials, 2013Co-Authors: Henglong Zhang, Xiaojuan Jia, Lihui XueAbstract:Abstract Organic expanded vermiculites (OEVMTs) were prepared using cetyltrimethyl ammonium bromide (CTAB) and octadecyl dimethyl benzyl ammonium chloride (ODBA) as intercalation agents. Effect of EVMT organic modification on physical and aging properties of styrene–butadiene–styrene (SBS) modified Bitumen was investigated. The microstructures of the binders were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. EVMT/SBS modified Bitumen forms a phase-separated structure, while OEVMT/SBS modified Bitumens form the exfoliated nanostructures according to XRD analysis. OEVMTs show the more obvious influence on physical properties of SBS modified Bitumen in comparison with EVMT. The compatibility between the EVMT and SBS modified Bitumen is also improved after organic modification of EVMT. AFM analysis indicates that the contrast between the dispersed phase and the matrix phase in SBS modified Bitumen increases with the addition of ODBA-EVMT. As a result of thin film oven test (TFOT), the viscosity aging index of SBS modified Bitumen decreases, while the retained ductility and penetration increase obviously with the introduction of EVMT and OEVMTs. ODBA-EVMT/SBS modified Bitumen has more pronounced improvements in aging resistance of SBS modified Bitumen in comparison with CTAB-EVMT/SBS modified Bitumen by preventing the phase-separated trend of the SBS modified Bitumen during TFOT.
Henglong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Effect of Rectorite and Its Organic Modification on Properties of Bitumen
Journal of Materials in Civil Engineering, 2015Co-Authors: Henglong Zhang, Chongzheng Zhu, Kezhen YanAbstract:Two organic rectorites (ORECs) were prepared by using cetyltrimethyl ammonium bromide (CTAB) and octadecyl dimethyl benzyl ammonium chloride (ODBA) as organic modifiers to modify the rectorites. Rectorite and OREC modified Bitumens were prepared by melt blending. Microstructures of the modified Bitumens were characterized by X-ray diffraction (XRD). The effect of rectorite (REC) and its organic modification on the physical and aging properties of Bitumen was investigated. X-ray diffraction results show that REC and ODBA-REC modified Bitumens form the intercalated nanostructure, whereas CTAB-REC modified Bitumen forms an exfoliated nanostructure. Compared with RECs, ORECs show the better compatibility with the Bitumen as well as the higher improvement in softening point, viscosity, and aging resistance of the Bitumen. The CTAB-REC modified Bitumen shows lower viscosity aging index values and softening point increment in comparison with the ODBA-REC modified Bitumen, indicating its good aging resistance.
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effect of ultraviolet aging on rheology chemistry and morphology of ultraviolet absorber modified Bitumen
Materials and Structures, 2013Co-Authors: Zhengang Feng, Henglong Zhang, Dongliang Kuang, Lihui XueAbstract:Seeking a new method to solve the ultraviolet (UV) aging of Bitumen is of great importance for road applications since the UV aging is considered to be one of the main causes leading to the performance deterioration of Bitumen. In this paper, two UV absorbers (octabenzone and bumetrizole) were applied to modify the Bitumen by melt blending. Effect of UV aging on rheology, chemistry and morphology of the UV absorber modified Bitumens was investigated, by means of dynamic shear rheometer, thin-layer chromatography with flame ionization detection, Fourier transform infrared spectroscopy and atomic force microscopy, to reveal the mechanisms of action for Bitumen and UV absorbers. Results show that the two UV absorbers show opposite influences on the UV aging performance of Bitumen depending on the type of UV absorbers. The bumetrizole improves the UV aging resistance of Bitumen remarkably since the bumetrizole can inhibit reactions of aromatization and oxidation of Bitumen molecules to a certain extent during the UV aging, and thus slows down the rate at which the Bitumen transforms from sol to gel. The bumetrizole modified Bitumen has the potential to be used in pavement for improvement of the UV aging resistance during service life.
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effect of expanded vermiculite on microstructures and aging properties of styrene butadiene styrene copolymer modified Bitumen
Construction and Building Materials, 2013Co-Authors: Henglong Zhang, Xiaojua Jia, Lihui XueAbstract:Abstract Organic expanded vermiculites (OEVMTs) were prepared using cetyltrimethyl ammonium bromide (CTAB) and octadecyl dimethyl benzyl ammonium chloride (ODBA) as intercalation agents. Effect of EVMT organic modification on physical and aging properties of styrene–butadiene–styrene (SBS) modified Bitumen was investigated. The microstructures of the binders were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. EVMT/SBS modified Bitumen forms a phase-separated structure, while OEVMT/SBS modified Bitumens form the exfoliated nanostructures according to XRD analysis. OEVMTs show the more obvious influence on physical properties of SBS modified Bitumen in comparison with EVMT. The compatibility between the EVMT and SBS modified Bitumen is also improved after organic modification of EVMT. AFM analysis indicates that the contrast between the dispersed phase and the matrix phase in SBS modified Bitumen increases with the addition of ODBA-EVMT. As a result of thin film oven test (TFOT), the viscosity aging index of SBS modified Bitumen decreases, while the retained ductility and penetration increase obviously with the introduction of EVMT and OEVMTs. ODBA-EVMT/SBS modified Bitumen has more pronounced improvements in aging resistance of SBS modified Bitumen in comparison with CTAB-EVMT/SBS modified Bitumen by preventing the phase-separated trend of the SBS modified Bitumen during TFOT.
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Effect of expanded vermiculite on microstructures and aging properties of styrene–butadiene–styrene copolymer modified Bitumen
Construction and Building Materials, 2013Co-Authors: Henglong Zhang, Xiaojuan Jia, Lihui XueAbstract:Abstract Organic expanded vermiculites (OEVMTs) were prepared using cetyltrimethyl ammonium bromide (CTAB) and octadecyl dimethyl benzyl ammonium chloride (ODBA) as intercalation agents. Effect of EVMT organic modification on physical and aging properties of styrene–butadiene–styrene (SBS) modified Bitumen was investigated. The microstructures of the binders were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. EVMT/SBS modified Bitumen forms a phase-separated structure, while OEVMT/SBS modified Bitumens form the exfoliated nanostructures according to XRD analysis. OEVMTs show the more obvious influence on physical properties of SBS modified Bitumen in comparison with EVMT. The compatibility between the EVMT and SBS modified Bitumen is also improved after organic modification of EVMT. AFM analysis indicates that the contrast between the dispersed phase and the matrix phase in SBS modified Bitumen increases with the addition of ODBA-EVMT. As a result of thin film oven test (TFOT), the viscosity aging index of SBS modified Bitumen decreases, while the retained ductility and penetration increase obviously with the introduction of EVMT and OEVMTs. ODBA-EVMT/SBS modified Bitumen has more pronounced improvements in aging resistance of SBS modified Bitumen in comparison with CTAB-EVMT/SBS modified Bitumen by preventing the phase-separated trend of the SBS modified Bitumen during TFOT.
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effect of aging on morphology of organo montmorillonite modified Bitumen by atomic force microscopy
Journal of Microscopy, 2011Co-Authors: Henglong Zhang, H C WangAbstract:The morphology of unmodified and organo-montmorillonite modified Bitumens was investigated by atomic force microscopy. The influence of thin film oven test and ultraviolet aging on the morphology of the binders was also analysed. The atomic force microscopy results showed that Bitumen displayed a 'bee-like' structure and the dimension of the 'bee-like' structures was decreased to some extent with the introduction of organo-montmorillonite. Organo-montmorillonite showed a better interaction with the dispersed domains in comparison with the matrix in Bitumen, which led to an obvious increase in the contrast between the dispersed domains and the matrix in Bitumen. Compared with the unmodified Bitumen, the single-phase trend in the organo-montmorillonite modified Bitumen could be effectively prevented during thin film oven test and ultraviolet aging, indicating its good aging resistance which was in accordance with changes in physical properties of the organo-montmorillonite modified Bitumen before and after aging.
Burak Şengöz - One of the best experts on this subject based on the ideXlab platform.
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Influence of Polyethylene on Fatigue Parameters of Bitumens
2018Co-Authors: Jülide Öner, Burak ŞengözAbstract:The use of polymer modified Bitumen has become a very important part of pavement construction due to its superior performance, including less ageing, enhanced rutting resistance and lower fatigue cracking properties. The polyethylene is a type of product normally not used as additive to Bitumen, generally showing a congealing point of 92-100°C. Areas where it has been used are for instance in plastics and polishes, as thickener for lubricating oils and petrolatum and as paraffin wax improver/up-grader. Although the many significant researches which have been carried out related to the polymer modified Bitumen in road applications, more studies should be undertaken on the compatibility, in the interaction between polymer and the different sources Bitumens according to the needs of refineries in different countries. The main purpose behind this study is to minimize the fatigue damage of waxes within Bitumens obtained from different sources. For this purpose; Bitumen samples were modified by recommended content of polyethylene polymer (at concentration of 1.5% by weight of the Bitumen). The intermediate temperature performance levels of polyethylene polymer modified Bitumens were determined by fatigue parameters.
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Investigation of rheological properties of transparent Bitumen
Construction and Building Materials, 2017Co-Authors: Burak Şengöz, Jülide Öner, Lansine Bagayogo, Ali TopalAbstract:Abstract In the last few years, transparent Bitumen has been used instead of traditional black Bitumen in order to construct roads in wide range of colors. Roads in natural earth color to bright red color, or livelier light blue to yellow or green or in any requested color can be constructed using transparent Bitumen. This paper reports the determination and comparison of the rheological properties of traditional black Bitumen and transparent Bitumen. Both base black Bitumen and transparent Bitumen were modified with 5% elastomeric type – Styrene Butadiene Styrene (SBS), and 2% plastomeric type – Ethylene Vinyl Acetate (EVA) polymer. Base and polymer modified Bitumens were subjected to conventional and rheological Bitumen tests. The intermediate and high temperature performances levels of Bitumen were determined according to the Superpave system by performing DSR test on aged and unaged samples. Rutting performance of each Bitumen sample was evaluated through zero shear viscosity (ZSV) and multiple stress creep recovery (MSCR) tests. Furthermore, the behavior of both traditional black Bitumen and transparent Bitumen at high and low frequencies levels at different temperatures were investigated by performing the Frequency Sweep test.
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evaluation of the properties and microstructure of sbs and eva polymer modified Bitumen
Construction and Building Materials, 2008Co-Authors: Burak Şengöz, Giray IsikyakarAbstract:Abstract This paper presents a laboratory study of modified Bitumen containing styrene–butadiene–styrene (SBS) and ethylene vinyl acetate (EVA) copolymers. The polymer modified Bitumen (PMB) samples have been prepared by means of multi purpose laboratory mixer depending on the type of the polymer. A 50/70 penetration grade base (unmodified) Bitumen has been mixed with SBS and EVA polymers at different proportions. The properties and morphology of the samples have been determined and characterized using conventional and empirical test methods and fluorescence microscopy. The mechanical properties of the hot-mix asphalt (HMA) containing SBS and EVA PMBs have also been analyzed and compared with HMA incorporating base Bitumen. The results indicated that, the morphology and properties of the modified Bitumens, as well as the mechanical properties of polymer modified HMA are dependent on the type of polymer and polymer content. At low polymer contents, the samples revealed the existence of dispersed polymer particles in a continuous Bitumen phase, whereas at high polymer contents a continuous polymer phase has been observed. Polymer modification improved the conventional properties of the base Bitumen such as; penetration, softening point, temperature susceptibility, etc. It was also concluded that, the mechanical properties of HMA prepared with the SBS PMB samples such as Marshall stability were enhanced with the increasing polymer contents.
C Gallegos - One of the best experts on this subject based on the ideXlab platform.
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effect of waste polymer addition on the rheology of modified Bitumen
Fuel, 2006Co-Authors: M Garciamorales, P Partal, F J Navarro, C GallegosAbstract:This paper deals with the modification of petroleum Bitumen with four different types of waste polymers. EVA, EVA/LDPE blend, crumb tire rubber and ABS, all of them coming from recycling plants of waste plastic materials, were used as modifying agents of the Bitumen employed in the pavement building. Optical microscopy, modulated calorimetry and a set of different rheological tests were developed in order to characterise the modified Bitumens. The results obtained reveal that tire rubber as well as its blends with other polymers can be considered as an interesting modifier of the Bitumen in a wide range of temperatures. As an elastomer, it endows the pavement a higher flexibility, which makes it more resistant to the traffic loading. The blend composed of EVA and LDPE displays quite promising results at high in-service temperatures, due to the development of a polymer network throughout the modified Bitumen. Furthermore, the calorimetry tests carried out demonstrate different degrees of compatibility between the Bitumen and the polymers used.
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viscous properties and microstructure of recycled eva modified Bitumen
Fuel, 2004Co-Authors: M Garciamorales, P Partal, F J Navarro, F J Martinezboza, C Gallegos, N Gonzalez, O Gonzalez, Maria Eugenia MunozAbstract:Abstract This paper deals with the viscous properties of recycled-polymer modified Bitumens (PMBs) in a wide range of temperatures. With this aim, two different penetration grade Bitumens (60/70 and 150/200) and recycled EVA copolymer (EVAR) from agriculture films were processed in an open reactor using a four blade propeller. Polymer concentration ranged from 0 to 9 wt%. Viscous flow and DSC measurements, from 5 to 165 °C, and optical microscopy, at room temperature, were performed on the samples. From the experimental results obtained, we may conclude that the viscous properties of Bitumen, at high temperature, are improved by adding recycled EVA copolymer in amounts that depend on Bitumen penetration grade. Moreover, significant microstructural changes, related to the development of a polymer-rich phase, tend to occur in the Bitumen as polymer concentration increased. These changes in microstructure have a significant influence on the flow behaviour of the binder and on its in-service performance. As a consequence, the use of recycled EVA in PMBs can be considered a suitable alternative from both environmental and economical points of view.
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influence of the processing conditions on the rheological behaviour of polymer modified Bitumen
Fuel, 2003Co-Authors: A Perezlepe, F J Martinezboza, C Gallegos, O Gonzalez, Maria Eugenia Munoz, Anton SantamariaAbstract:Abstract Mixing polymers into Bitumen has important consequences on the engineering properties of bituminous binders. Thus, structural and chemical changes may be observed during processing of polymer-modified Bitumens. Chemical compatibility and processing conditions are crucial to obtain suitable properties. Most polymers occur to be insoluble, in some degree, in the Bitumen matrix, and phase separation may result. Polymer stabilization can be achieved by mechanical dispersion of the modifier and swelling by compatible components in the maltene fraction. This paper deals with the influences that processing variables exert on the rheological properties of polymer-modified Bitumens. From the experimental results obtained we may conclude that a rotor–stator mixer device enhances the rheological properties of binders prepared with high-density polyethylene, low-density polyethylene, ethylene–propylene–diene monomer, and their blends, as compared to a stirred tank device.
Per Redelius - One of the best experts on this subject based on the ideXlab platform.
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Wax morphology in Bitumen
Journal of Materials Science, 2005Co-Authors: Maud Langton, P. Olofsson, Per RedeliusAbstract:Wax crystallisation and melting in Bitumen is usually considered detrimental to Bitumen quality and asphalt performance. The objectives of this paper are to study wax morphology in Bitumen and to investigate effects of time, temperature, and thermal cycling on wax crystallisation. Various samples were selected, including eight waxy Bitumens of different sources and three laboratory blends prepared by adding a slack wax and two isolated Bitumen waxes to the non-waxy Bitumen. Test methods used were differential scanning calorimetry (DSC), polarised light microscopy (PLM), confocal laser scanning microscopy (CLSM), and freeze etching (fracture) in combination with transmission electron microscopy (FF-TEM). The DSC results indicated that the selected Bitumen samples differ widely in wax content and wax crystallisation starting and melting out temperatures. It was found that non-waxy Bitumen displayed no structure or crystals neither in PLM, CLSM or FF-TEM, while waxy Bitumens from different crude origins showed a large variation of structures. The morphology of wax crystals was highly dependent on crystallisation temperature as well as temperature history. The wax which has been isolated from waxy Bitumen and mixed into non-waxy Bitumen displayed similar morphology as the wax in the original Bitumen. It was also found that Bitumen wax usually melted at temperatures lower than 60°C although in one case a temperature of 80°C was needed until complete melting of the wax.
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Rheological effects of waxes in Bitumen
Energy & Fuels, 2003Co-Authors: Ylva Edwards, Per RedeliusAbstract:Rheological effects of adding two Bitumen waxes (isolated from SEC−II fraction) to three Bitumens were studied using dynamic mechanical analysis (DMA). Also, a commercially available slack wax was used in the study. The results show that the magnitude and type of effect on Bitumen rheology depend on the Bitumen and type of crystallizing fraction in the Bitumen. Effects due to wax content shown in DMA temperature sweeps are well related to the corresponding effects shown in DSC thermograms. The slope of the logarithm of the complex modulus between 25 °C and 60 °C is introduced as a possible proper factor for predicting rutting sensitivity due to wax content.
