The rutting and low-temperature resistances of warm-mix recycled asphalt binders under the secondary aging condition were measured by the dynamic shear rheometer test and bending beam rheometer test.Effects of differe...The rutting and low-temperature resistances of warm-mix recycled asphalt binders under the secondary aging condition were measured by the dynamic shear rheometer test and bending beam rheometer test.Effects of different types of warm-mix asphalt(WMA)technologies and additives were evaluated.Aging and improvement mechanisms were investigated by the Fourier transform infrared spectroscopy test.It is found that recycled binders after the secondary aging are more resistant to rutting and less resistant to low-temperature cracking.The two warm-mix asphalt technologies have opposite effects.Using the Sasobit WMA significantly improves the rutting resistance and reduces the low temperature resistance for the recycled binders due to its morphological change at different temperatures.The rutting factor values of recycled asphalt binders with the Sasobit additive increase by 4.6 to 5.6 times.However,using the Evotherm WMA causes the deterioration of the rutting resistance due to the structural lubrication effect.The rutting factor values of recycled asphalt binders with the Evotherm additive show the reduction of 52%to 62%.It is recommended to add the styrene butadiene rubber latex or crumb rubber powder into the warm-mix recycled asphalt binders to simultaneously improve the rutting and low-temperature cracking resistances.展开更多
Within the past two decades or so, the asphalt paving industry has responded positively to increasing global concerns over shrinking natural resource reserves and worsening environmental conditions through the develop...Within the past two decades or so, the asphalt paving industry has responded positively to increasing global concerns over shrinking natural resource reserves and worsening environmental conditions through the development and deployment of warm-mix asphalt technologies. Such technologies make it possible to produce and place asphalt concrete at reduced temperatures compared to conventional hot-mix methods. Several studies have reported on the potential of warm-mix asphalt with regard to improved pavement performance, efficiency and environmental stewardship. This paper reviews several of those studies in the context of pavement sustainability. Overall, warm-mix asphalt provides substantial sustainability benefits similar to or, in some cases, better than conventional hot-mix asphalt. Sustainability benefits include lower energy use, reduced emissions, and potential for increased reclaimed asphalt pavement usage. Growth in utilization of warm-mix asphalt worldwide may, in the not-too-distant future, make the material the standard for asphalt paving. Regardless, there are concerns over some aspects of warm-mix asphalt such as lower resistance to fatigue cracking, rutting and potential water-susceptibility problems, particularly with mixes prepared with water-based technologies, which require further research to address.展开更多
基金The Natural Science Foundation of Jiangsu Province(No.BK20181404)Qing Lan Project(2016)the Training Plan Project for Young Core Teachers of Nanjing Forestry University(2017).
文摘The rutting and low-temperature resistances of warm-mix recycled asphalt binders under the secondary aging condition were measured by the dynamic shear rheometer test and bending beam rheometer test.Effects of different types of warm-mix asphalt(WMA)technologies and additives were evaluated.Aging and improvement mechanisms were investigated by the Fourier transform infrared spectroscopy test.It is found that recycled binders after the secondary aging are more resistant to rutting and less resistant to low-temperature cracking.The two warm-mix asphalt technologies have opposite effects.Using the Sasobit WMA significantly improves the rutting resistance and reduces the low temperature resistance for the recycled binders due to its morphological change at different temperatures.The rutting factor values of recycled asphalt binders with the Sasobit additive increase by 4.6 to 5.6 times.However,using the Evotherm WMA causes the deterioration of the rutting resistance due to the structural lubrication effect.The rutting factor values of recycled asphalt binders with the Evotherm additive show the reduction of 52%to 62%.It is recommended to add the styrene butadiene rubber latex or crumb rubber powder into the warm-mix recycled asphalt binders to simultaneously improve the rutting and low-temperature cracking resistances.
文摘Within the past two decades or so, the asphalt paving industry has responded positively to increasing global concerns over shrinking natural resource reserves and worsening environmental conditions through the development and deployment of warm-mix asphalt technologies. Such technologies make it possible to produce and place asphalt concrete at reduced temperatures compared to conventional hot-mix methods. Several studies have reported on the potential of warm-mix asphalt with regard to improved pavement performance, efficiency and environmental stewardship. This paper reviews several of those studies in the context of pavement sustainability. Overall, warm-mix asphalt provides substantial sustainability benefits similar to or, in some cases, better than conventional hot-mix asphalt. Sustainability benefits include lower energy use, reduced emissions, and potential for increased reclaimed asphalt pavement usage. Growth in utilization of warm-mix asphalt worldwide may, in the not-too-distant future, make the material the standard for asphalt paving. Regardless, there are concerns over some aspects of warm-mix asphalt such as lower resistance to fatigue cracking, rutting and potential water-susceptibility problems, particularly with mixes prepared with water-based technologies, which require further research to address.
