Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to des...Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.展开更多
Fume suppression mechanisms and the effect of expanded graphite on the performance of asphalt were studied by applying infrared spectroscopy（FT-IR）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and ...Fume suppression mechanisms and the effect of expanded graphite on the performance of asphalt were studied by applying infrared spectroscopy（FT-IR）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and comprehensive thermal analysis（TG, DSC）. The experimental results confirm that asphalt which is mixed with expandable graphite will expand in the process of hot mix, and the expanded graphite layer will swell by the light component in the asphalt. The light component in the asphalt and PAHs adsorption on expanded graphite surface or part of the plug in the expanded graphite layer between plates made nucleation crystallization growth. And the Van der Waals force and the bonding of the lattice can effectively restrain the asphalt fume release. Meanwhile, the expanding agent with oxidative can spread into the asphalt, leading to asphalt oxygenated and plastic abate, while the ductility decreases. Expanded graphite, SBS modifier and environment- friendly plasticizers are used to composite modified asphalt. According to asphalt fume release experiment, normal test of asphalt performance, Brookfield viscosity test, RTFOT test and asphalt mixture tests（high temperature stability, low temperature stability, water stability）, it has been proven that the modified asphalt’s performance is better than that of matrix asphalt and equivalent to that of SBS modified asphalt. Furthermore, it has good fume suppression effect.展开更多
Waste plastics and rubber have always posed a threat to the environment and a great challenge for disposal.The use of these two waste materials as modifiers for road asphalt provides new road asphalt binders and at th...Waste plastics and rubber have always posed a threat to the environment and a great challenge for disposal.The use of these two waste materials as modifiers for road asphalt provides new road asphalt binders and at the same time provides a new way for waste material resource treatment.Rubber-modified asphalt and plastic-modified asphalt have received widespread attention due to their green and low-carbon characteristics and some performance advantages,but there are still some performance shortcomings that hinder their promotion and application.In order to continue to explore the application of waste materials in the field of road engineering,combined with the performance advantages of both,many scholars began to study the rubber-plastic composite modified asphalt(RPCMA).Therefore,this paper reviewed the different types of waste rubber and plastic,the comprehensive performance of different types of asphalt and its mixture performance,analyzed the modification mechanism of rubber-plastic composite modified asphalt and its performance changes.The results show that rubber-plastic composite modified asphalt is mostly prepared by directly adding modified materials.However,the pretreatment or melt granulation of rubber and plastic will make the performance of rubber-plastic modified asphalt has improved.There is a mutual promotion mechanism between rubber and plastic in asphalt,which makes the performance of rubber-plastic modified asphalt better than that of asphalt obtained by a single modification method(rubber modified asphalt or plastic modified asphalt).In some properties,it can be close to the commercial SBS modified asphalt.The performance of rubber and plastic composite modified asphalt at high temperature has been generally recognized by researchers,but its low-temperature performance is still controversial.Therefore,it is recommended to apply in high-temperature areas.Future work should focus on the development of composite modifiers with stable performance,low cost and ease of use,standardization of modification processes,improvement of low-temperature performance,and monitoring of road performance and environmental impact.展开更多
基金the Scientific Technology R&D Project of CCCC Asset Management Co.,Ltd.(RP2022015294&RP2022015296).
文摘Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.
基金Funded by the National Natural Science Foundation of China(No.51078372)the Doctoral Program of Higher Specialized Research Foundation(No.20105522110002)
文摘Fume suppression mechanisms and the effect of expanded graphite on the performance of asphalt were studied by applying infrared spectroscopy（FT-IR）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and comprehensive thermal analysis（TG, DSC）. The experimental results confirm that asphalt which is mixed with expandable graphite will expand in the process of hot mix, and the expanded graphite layer will swell by the light component in the asphalt. The light component in the asphalt and PAHs adsorption on expanded graphite surface or part of the plug in the expanded graphite layer between plates made nucleation crystallization growth. And the Van der Waals force and the bonding of the lattice can effectively restrain the asphalt fume release. Meanwhile, the expanding agent with oxidative can spread into the asphalt, leading to asphalt oxygenated and plastic abate, while the ductility decreases. Expanded graphite, SBS modifier and environment- friendly plasticizers are used to composite modified asphalt. According to asphalt fume release experiment, normal test of asphalt performance, Brookfield viscosity test, RTFOT test and asphalt mixture tests（high temperature stability, low temperature stability, water stability）, it has been proven that the modified asphalt’s performance is better than that of matrix asphalt and equivalent to that of SBS modified asphalt. Furthermore, it has good fume suppression effect.
基金sponsored by National Natural Science Foundation of China(No.52308466,No.42271144,No.42071100)Key Research and Development Project of Shaanxi Province(2022SF-328,2022GY-427)+1 种基金the SASAC Science and Technology Innovation Project(JF-23-01-0063)Shaanxi Provincial Transportation Research Project(24-19K,24-20K).
文摘Waste plastics and rubber have always posed a threat to the environment and a great challenge for disposal.The use of these two waste materials as modifiers for road asphalt provides new road asphalt binders and at the same time provides a new way for waste material resource treatment.Rubber-modified asphalt and plastic-modified asphalt have received widespread attention due to their green and low-carbon characteristics and some performance advantages,but there are still some performance shortcomings that hinder their promotion and application.In order to continue to explore the application of waste materials in the field of road engineering,combined with the performance advantages of both,many scholars began to study the rubber-plastic composite modified asphalt(RPCMA).Therefore,this paper reviewed the different types of waste rubber and plastic,the comprehensive performance of different types of asphalt and its mixture performance,analyzed the modification mechanism of rubber-plastic composite modified asphalt and its performance changes.The results show that rubber-plastic composite modified asphalt is mostly prepared by directly adding modified materials.However,the pretreatment or melt granulation of rubber and plastic will make the performance of rubber-plastic modified asphalt has improved.There is a mutual promotion mechanism between rubber and plastic in asphalt,which makes the performance of rubber-plastic modified asphalt better than that of asphalt obtained by a single modification method(rubber modified asphalt or plastic modified asphalt).In some properties,it can be close to the commercial SBS modified asphalt.The performance of rubber and plastic composite modified asphalt at high temperature has been generally recognized by researchers,but its low-temperature performance is still controversial.Therefore,it is recommended to apply in high-temperature areas.Future work should focus on the development of composite modifiers with stable performance,low cost and ease of use,standardization of modification processes,improvement of low-temperature performance,and monitoring of road performance and environmental impact.
