The carbon emissions arising from road pavement infrastructures have emerged as critical issue in recent years.The life cycle of a pavement can be divided into five phases,namely raw materials and production,construct...The carbon emissions arising from road pavement infrastructures have emerged as critical issue in recent years.The life cycle of a pavement can be divided into five phases,namely raw materials and production,construction,use,maintenance and end of life.While the use phase generates the highest carbon emissions throughout the pavement's life cycle,it is usually neglected in most pavement life cycle assessment(LCA)studies due to its complexity and uncertainty.Therefore,this review selected 126 relevant references,focuses on quantification methods,influential factors and reduction technologies of carbon emissions in pavement use phase.Among the carbon accounting approached,the LCA approach,remains the most widely used for evaluating the environmental impact of pavements.Second,the primary influential factors on the use phase'carbon emission include pavement-vehicle interaction primarily affected by pavement roughness,pavement albedo and climate change.Most influential factors above indirectly cause changes in carbon emissions by influencing the pavement performance and subsequent vehicle emissions.Finally,the review surveys carbon emission reduction technologies during pavement use phase,focusing mainly on reducing pavement rolling resistance and constructing cool pavements.Reflective pavements and permeable pavements are the most widely used cool pavement technologies.Overall,the aspects involved in this paper hold significant promise for quantifying and reducing carbon emissions in the pavement use phase.展开更多
This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance.The rapid curing process of polyurethane binder determines the limited time window for mixing and constructi...This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance.The rapid curing process of polyurethane binder determines the limited time window for mixing and construction of polyurethane-bonded mixture(PUM),which presents significant difference with hot-mix asphalt(HMA)technology.Therefore,this research investigated and optimized the mix design of PUM for airport thin-overlay technology based on its thermosetting characteristics.First,limestone and basalt were comprehensively compared as an aggregate for PUM.Then,the effects of molding and curing conditions were studied in terms of mixing time,molding method,molding parameters and curing temperature.Statistical analysis was also conducted to evaluate the effects of gradation and particle size on PUM performances based on gray relational analysis(GRA),thus determining the key particle size to control PUM performances.Finally,the internal structural details of PUM were captured by X-ray CT scan test.The results demonstrated that it only took 12 hours to reach 75%of maximum strength at a curing temperature of 50°C,indicating an efficient curing process and in turn allowing short traffic delay.The internal structural details of PUM presented distribution of tiny pores with few connective voids,guaranteeing waterproof property and high strength.展开更多
Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving,but its low cohesive strength and poor mechanical properties limit its wide application,even with polymer modification.In this ...Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving,but its low cohesive strength and poor mechanical properties limit its wide application,even with polymer modification.In this study,Styrene-Butadiene Rubber(SBR)emulsified asphalt was modified with nano-cellulose materials,namely nano paper-cellulose(NPC)and wood-derived nano-cellulose(WDC),to improve its properties.A novel preparation method of nano-cellulose solution was developed,including blending,ultrasonic stirring,and centrifugal treatment.Four types of nano-cellulose solution(0.5%NPC,0.5%,1.0%,and 1.5%WDC by weight of water)were selected.The microscopy analysis indicated that 0.5%WDC emulsion had a smaller particle size than 1.5%WDC emulsion.The rheology test indicated that WDC modified residue improved rutting resistance with the increased solution dosage due to the cross-linking effect,but its creep-and-recovery performance was worse than that of SBR emulsion residue.The NPC modified binder had a higher rutting factor than WDC modified binder at the same dosage after short-term aging.In addition,1.0%WDC could be regarded as the optimal dosage in terms of fatigue and low-temperature performance.Furthermore,Fourier Transform Infrared Spectroscopy(FTIR)results showed that 0.5%NPC modified residue performed better in long-term aging resistance compared with 0.5%WDC modified asphalt.展开更多
基金supported by the National Natural Science Foundation of China under the project numbers of 51861145402 and 51778478.
文摘The carbon emissions arising from road pavement infrastructures have emerged as critical issue in recent years.The life cycle of a pavement can be divided into five phases,namely raw materials and production,construction,use,maintenance and end of life.While the use phase generates the highest carbon emissions throughout the pavement's life cycle,it is usually neglected in most pavement life cycle assessment(LCA)studies due to its complexity and uncertainty.Therefore,this review selected 126 relevant references,focuses on quantification methods,influential factors and reduction technologies of carbon emissions in pavement use phase.Among the carbon accounting approached,the LCA approach,remains the most widely used for evaluating the environmental impact of pavements.Second,the primary influential factors on the use phase'carbon emission include pavement-vehicle interaction primarily affected by pavement roughness,pavement albedo and climate change.Most influential factors above indirectly cause changes in carbon emissions by influencing the pavement performance and subsequent vehicle emissions.Finally,the review surveys carbon emission reduction technologies during pavement use phase,focusing mainly on reducing pavement rolling resistance and constructing cool pavements.Reflective pavements and permeable pavements are the most widely used cool pavement technologies.Overall,the aspects involved in this paper hold significant promise for quantifying and reducing carbon emissions in the pavement use phase.
基金This study was supported by the National Natural Science Foundation of China under Grant number of 51861145402.
文摘This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance.The rapid curing process of polyurethane binder determines the limited time window for mixing and construction of polyurethane-bonded mixture(PUM),which presents significant difference with hot-mix asphalt(HMA)technology.Therefore,this research investigated and optimized the mix design of PUM for airport thin-overlay technology based on its thermosetting characteristics.First,limestone and basalt were comprehensively compared as an aggregate for PUM.Then,the effects of molding and curing conditions were studied in terms of mixing time,molding method,molding parameters and curing temperature.Statistical analysis was also conducted to evaluate the effects of gradation and particle size on PUM performances based on gray relational analysis(GRA),thus determining the key particle size to control PUM performances.Finally,the internal structural details of PUM were captured by X-ray CT scan test.The results demonstrated that it only took 12 hours to reach 75%of maximum strength at a curing temperature of 50°C,indicating an efficient curing process and in turn allowing short traffic delay.The internal structural details of PUM presented distribution of tiny pores with few connective voids,guaranteeing waterproof property and high strength.
基金This study was supported by the National Natural Science Foundation of China(Grant No.51778478).
文摘Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving,but its low cohesive strength and poor mechanical properties limit its wide application,even with polymer modification.In this study,Styrene-Butadiene Rubber(SBR)emulsified asphalt was modified with nano-cellulose materials,namely nano paper-cellulose(NPC)and wood-derived nano-cellulose(WDC),to improve its properties.A novel preparation method of nano-cellulose solution was developed,including blending,ultrasonic stirring,and centrifugal treatment.Four types of nano-cellulose solution(0.5%NPC,0.5%,1.0%,and 1.5%WDC by weight of water)were selected.The microscopy analysis indicated that 0.5%WDC emulsion had a smaller particle size than 1.5%WDC emulsion.The rheology test indicated that WDC modified residue improved rutting resistance with the increased solution dosage due to the cross-linking effect,but its creep-and-recovery performance was worse than that of SBR emulsion residue.The NPC modified binder had a higher rutting factor than WDC modified binder at the same dosage after short-term aging.In addition,1.0%WDC could be regarded as the optimal dosage in terms of fatigue and low-temperature performance.Furthermore,Fourier Transform Infrared Spectroscopy(FTIR)results showed that 0.5%NPC modified residue performed better in long-term aging resistance compared with 0.5%WDC modified asphalt.
