The objective of this paper was to find new modifier to improve the aging resistance and low temperature cracking resistance of asphalt. To investigate the aging resistance of modified asphalt binders, mesoporous nano...The objective of this paper was to find new modifier to improve the aging resistance and low temperature cracking resistance of asphalt. To investigate the aging resistance of modified asphalt binders, mesoporous nano-silica（doping Ti^（4＋）） was used as a asphalt modifier. Some physical properties including penetration, ductility, and softening point of asphalt were analyzed with RTFO（Rotating thin film oven） aging and ultraviolet aging. Moreover, the performances of high and low temperature of modified asphalt binders with pressure aging were tested by dynamic shear rheometer（DSR） test and bending beam rheometer（BBR） test. These results showed that the penetration decreased, low temperature ductility, and softening point increased when adding mesoporous nano-silica to base asphalt. After ultraviolet radiation aging, the penetration loss and ductility loss of modified asphalt decreased than that of original asphalt, the increase of softening point was also significantly reduced than that of base asphalt. Furthermore, The test results of DSR and BBR showed that the G＊sinδ and creep modulus‘s＇ of pressure aged asphalt decreased, but the creep rate ‘m＇ increased. It can be concluded that the aging resistance and cracking resistance of modified asphalt are improved by adding mesoporous nano-silica, especially the doping of Ti^（4＋） could improve the aging resistance obviously.展开更多
A new method was used to evaluate the fatigue properties of the bonding layer used in the bridge deck pavement. The shear fatigue test of three bonding layers was conducted on a dynamic shear rheometer（DSR）. The fat...A new method was used to evaluate the fatigue properties of the bonding layer used in the bridge deck pavement. The shear fatigue test of three bonding layers was conducted on a dynamic shear rheometer（DSR）. The fatigue formulas were gained for these layers. The experimental results indicate that, at the same torque level or at the same frequency, neoprene latex asphalt bonding layer exhibits excellent fatigue performance when compared to other two bonding layers.展开更多
In order to study the chemical modification mechanism and rheological properties of polyphosphoric acid (PPA)-modified asphalt,asphalt modified with different PPA contents were characterized by four-component test,ato...In order to study the chemical modification mechanism and rheological properties of polyphosphoric acid (PPA)-modified asphalt,asphalt modified with different PPA contents were characterized by four-component test,atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR).In the test,changes in asphalt chemical composition and colloidal structure were analyzed for different PPA contents,and infrared spectra were fitted with a Gaussian function.The reaction mechanism of PPA and matrix asphalt was also discussed.Based on dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test,rheological index G~*/sinδ and S/m were used to evaluate the modification effect of PPA on asphalt.The results show that,with an increase in PPA content,both large and small honeycomb structures increased in the three-dimensional topography seen in the atomic force microscope (AFM).In a certain space range,some of the micelles in the asphalt are connected each other to form interlocking skeleton structures,and locally form dense spatial network structures.The added PPA does not chemically react with the functional groups in the functional-group area of the infrared spectra (3 100-2 750 cm^(-1),1 800-1 330 cm^(-1)),and the structure is very stable.However,there is an obvious new absorption peak below 1 330 cm^(-1) in the fingerprint area,that is,the chemical reaction between PPA and the matrix asphalt generates a new compound,inorganic phosphate.Infrared spectra of PPA-modified asphalt with different contents were fitted by a Gaussian function,which makes up for the limitation that the absorption intensity information of each superimposed functional group cannot be obtained directly from the original infrared spectra.Results of this qualitative analysis were further verified by quantitative analysis.The addition of PPA can effectively improve the high and low-temperature performance of asphalt,and the lower the temperature is in the negative temperature zone,the more obvious the improvement is.When PPA content is more than 1%,the improvement of asphalt low-temperature performance is not obvious.展开更多
基金Funded by the China Scholarship Council(201506375019)
文摘The objective of this paper was to find new modifier to improve the aging resistance and low temperature cracking resistance of asphalt. To investigate the aging resistance of modified asphalt binders, mesoporous nano-silica（doping Ti^（4＋）） was used as a asphalt modifier. Some physical properties including penetration, ductility, and softening point of asphalt were analyzed with RTFO（Rotating thin film oven） aging and ultraviolet aging. Moreover, the performances of high and low temperature of modified asphalt binders with pressure aging were tested by dynamic shear rheometer（DSR） test and bending beam rheometer（BBR） test. These results showed that the penetration decreased, low temperature ductility, and softening point increased when adding mesoporous nano-silica to base asphalt. After ultraviolet radiation aging, the penetration loss and ductility loss of modified asphalt decreased than that of original asphalt, the increase of softening point was also significantly reduced than that of base asphalt. Furthermore, The test results of DSR and BBR showed that the G＊sinδ and creep modulus‘s＇ of pressure aged asphalt decreased, but the creep rate ‘m＇ increased. It can be concluded that the aging resistance and cracking resistance of modified asphalt are improved by adding mesoporous nano-silica, especially the doping of Ti^（4＋） could improve the aging resistance obviously.
基金Funded by the National Natural Science Foundation of China (No. 50878171)
文摘A new method was used to evaluate the fatigue properties of the bonding layer used in the bridge deck pavement. The shear fatigue test of three bonding layers was conducted on a dynamic shear rheometer（DSR）. The fatigue formulas were gained for these layers. The experimental results indicate that, at the same torque level or at the same frequency, neoprene latex asphalt bonding layer exhibits excellent fatigue performance when compared to other two bonding layers.
基金Funded by National Natural Science Foundation of China(No.11962024)Inner Mongolia Transportation Technology Project(No.NJ-2014-9)Research Fund for the Doctoral Program of Higher Education of China(RFDP)(No.BS2020042)。
文摘In order to study the chemical modification mechanism and rheological properties of polyphosphoric acid (PPA)-modified asphalt,asphalt modified with different PPA contents were characterized by four-component test,atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR).In the test,changes in asphalt chemical composition and colloidal structure were analyzed for different PPA contents,and infrared spectra were fitted with a Gaussian function.The reaction mechanism of PPA and matrix asphalt was also discussed.Based on dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test,rheological index G~*/sinδ and S/m were used to evaluate the modification effect of PPA on asphalt.The results show that,with an increase in PPA content,both large and small honeycomb structures increased in the three-dimensional topography seen in the atomic force microscope (AFM).In a certain space range,some of the micelles in the asphalt are connected each other to form interlocking skeleton structures,and locally form dense spatial network structures.The added PPA does not chemically react with the functional groups in the functional-group area of the infrared spectra (3 100-2 750 cm^(-1),1 800-1 330 cm^(-1)),and the structure is very stable.However,there is an obvious new absorption peak below 1 330 cm^(-1) in the fingerprint area,that is,the chemical reaction between PPA and the matrix asphalt generates a new compound,inorganic phosphate.Infrared spectra of PPA-modified asphalt with different contents were fitted by a Gaussian function,which makes up for the limitation that the absorption intensity information of each superimposed functional group cannot be obtained directly from the original infrared spectra.Results of this qualitative analysis were further verified by quantitative analysis.The addition of PPA can effectively improve the high and low-temperature performance of asphalt,and the lower the temperature is in the negative temperature zone,the more obvious the improvement is.When PPA content is more than 1%,the improvement of asphalt low-temperature performance is not obvious.
