Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pave...Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pavement,which will lead to the poor overall quality of road and bridge projects.Therefore,it should be applied reasonably.Advanced testing technologies are used to test the mixture quality,compaction,segregation,thickness,and other aspects of the asphalt pavement surface layer,so as to improve the quality of the asphalt pavement surface layer,and then improve the overall quality of road and bridge construction.Therefore,this paper mainly analyzes the technologies for asphalt pavement surface layer testing in road and bridge engineering construction.展开更多
A model for predicting the interface behavior of epoxy asphalt and steel composite beam under negative bending is developed incorporating partial interaction theory. Interfacial slips between the steel deck and the ep...A model for predicting the interface behavior of epoxy asphalt and steel composite beam under negative bending is developed incorporating partial interaction theory. Interfacial slips between the steel deck and the epoxy asphalt surfacing are included in the model with a new parameter of membrane stiffness. A series of analytical equations based on this model are derived to calculate slip and strain at the interface. Also, a numerical procedure for calculating the load responses of simply supported composite beams with concentrated force at the mid-span is established and verified with two samples. Characters of slip and strain at the interface, sensitivities of tensile stress and interface shear stress with material parameters are studied. It can be concluded that interfacial effects decrease the bending stiffness of the composite; hard and stiff bonding material is better for asphalt surfacing layer working at normal to low temperatures, and the damage of the asphalt surfacing layer will be accelerated with the damage accumulation of the bonding coat.展开更多
High temperature rutting is a typical highway damage in Xinjiang, China, and its trigger process usually has a close relationship with characteristics of road temperature distribution. A numerical model of earth-atmos...High temperature rutting is a typical highway damage in Xinjiang, China, and its trigger process usually has a close relationship with characteristics of road temperature distribution. A numerical model of earth-atmosphere coupling heat transfer on a typical section of the Beijing-Xinjiang Expressway(G7) from Wutong Daquan to Yiwu was established in this work. Spatiotemporal characteristics of pavement structure layer temperature distribution, frequency and duration times of road surface high temperature from May 1 to September 30 are statistically studied. The effects of wind speed, weather and air temperature on asphalt layer and pavement temperature are analyzed. The results show that:(1) Spatial and temporal temperature distribution characteristics of pavement structural layers are greatly affected by the coupled earth-atmosphere heat transfer process. Surface temperature increases along the airflow direction and daily temperature variation of the pavement structure layer decreases with an increase of depth.(2) G7 expressway will face the challenge of high rutting damage. The proportion of temperature higher than 50 ℃ for pavement surface and asphalt upper layer both exceeds 50%and high temperature of road lasts for more than six hours in numerous days.(3) High temperatures of asphalt pavement are usually associated with low ambient wind speeds, while the wind flow has little cooling effect when the road surface temperature is relative high. Weather conditions have a significant impact on temperature of the road surface. The probability of high temperature in sunny days is obviously higher than other weather conditions.(4) Pavement temperature rises as air temperature rises. When air temperature is higher than 30 °C, the proportion of pavement daily maximum temperature over softening point reaches up to 78%.展开更多
Tremolite group minerals could be present in the aggregate used as filler in the mix asphalt floor in the road surfaces and are subject to wear for vehicular traffic and materials ageing.Dust produced by the degradati...Tremolite group minerals could be present in the aggregate used as filler in the mix asphalt floor in the road surfaces and are subject to wear for vehicular traffic and materials ageing.Dust produced by the degradation of asphalt surfaces can disperse tremolite group minerals present in road paving causing exposure by asbestos fiber to an increasing number of people and animals.In recent years,attention has been focused on naturally occurring asbestos(NOA)as the greatest frequency of lung cancer has been observed in environments characterized by rocks and soils rich in Tremolite that characterize asbestos minerals.Asphalt samples object of this study were collected in a motorway segment of the Lombardia Region(north of Italy)for an exposure assessment research on road paving workers.The evaluation was performed using a metrological approach based on petrographic and mineralogical analyses in order to reduce the epidemiologic risks and to define the best treatment strategies on waste management with sustainable costs in fulfilment of Council Directive 67/548/EEC(1967)and EC Regulation 1272/2008(2008)(Paglietti et al.,2016).The fibers are generally not broken down to other compounds in the environment,but asbestos hazard could be related to the occurrence of tremolite fiber in road paving arises when natural weathering processes(e.g.,erosion)or human activities(e.g.,continuous passage of motorized vehicles)separate and break down the fibers,which could be lost into the environment as airborne and easily penetrate into the human respiratory tract(Punturo et al.,2019).Despite this,this work is not an epidemiological risk analysis but obtained data could be useful to other specialists to define the exposure risks.展开更多
文摘Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pavement,which will lead to the poor overall quality of road and bridge projects.Therefore,it should be applied reasonably.Advanced testing technologies are used to test the mixture quality,compaction,segregation,thickness,and other aspects of the asphalt pavement surface layer,so as to improve the quality of the asphalt pavement surface layer,and then improve the overall quality of road and bridge construction.Therefore,this paper mainly analyzes the technologies for asphalt pavement surface layer testing in road and bridge engineering construction.
基金The National Natural Science Foundation of China(No50578038)
文摘A model for predicting the interface behavior of epoxy asphalt and steel composite beam under negative bending is developed incorporating partial interaction theory. Interfacial slips between the steel deck and the epoxy asphalt surfacing are included in the model with a new parameter of membrane stiffness. A series of analytical equations based on this model are derived to calculate slip and strain at the interface. Also, a numerical procedure for calculating the load responses of simply supported composite beams with concentrated force at the mid-span is established and verified with two samples. Characters of slip and strain at the interface, sensitivities of tensile stress and interface shear stress with material parameters are studied. It can be concluded that interfacial effects decrease the bending stiffness of the composite; hard and stiff bonding material is better for asphalt surfacing layer working at normal to low temperatures, and the damage of the asphalt surfacing layer will be accelerated with the damage accumulation of the bonding coat.
基金supported by the China Railway Construction Group Scientific Research and Development Project(ZTJ2021WBXKYKT)Natural Science Foundation of Shaanxi Province(Grant No.2022JM143)+1 种基金the Fundamental Research Funds for the Central Universities,CHD(Grant No.300102262104)the National Science Foundation of China(Grant Nos.41502292,51574037)。
文摘High temperature rutting is a typical highway damage in Xinjiang, China, and its trigger process usually has a close relationship with characteristics of road temperature distribution. A numerical model of earth-atmosphere coupling heat transfer on a typical section of the Beijing-Xinjiang Expressway(G7) from Wutong Daquan to Yiwu was established in this work. Spatiotemporal characteristics of pavement structure layer temperature distribution, frequency and duration times of road surface high temperature from May 1 to September 30 are statistically studied. The effects of wind speed, weather and air temperature on asphalt layer and pavement temperature are analyzed. The results show that:(1) Spatial and temporal temperature distribution characteristics of pavement structural layers are greatly affected by the coupled earth-atmosphere heat transfer process. Surface temperature increases along the airflow direction and daily temperature variation of the pavement structure layer decreases with an increase of depth.(2) G7 expressway will face the challenge of high rutting damage. The proportion of temperature higher than 50 ℃ for pavement surface and asphalt upper layer both exceeds 50%and high temperature of road lasts for more than six hours in numerous days.(3) High temperatures of asphalt pavement are usually associated with low ambient wind speeds, while the wind flow has little cooling effect when the road surface temperature is relative high. Weather conditions have a significant impact on temperature of the road surface. The probability of high temperature in sunny days is obviously higher than other weather conditions.(4) Pavement temperature rises as air temperature rises. When air temperature is higher than 30 °C, the proportion of pavement daily maximum temperature over softening point reaches up to 78%.
文摘Tremolite group minerals could be present in the aggregate used as filler in the mix asphalt floor in the road surfaces and are subject to wear for vehicular traffic and materials ageing.Dust produced by the degradation of asphalt surfaces can disperse tremolite group minerals present in road paving causing exposure by asbestos fiber to an increasing number of people and animals.In recent years,attention has been focused on naturally occurring asbestos(NOA)as the greatest frequency of lung cancer has been observed in environments characterized by rocks and soils rich in Tremolite that characterize asbestos minerals.Asphalt samples object of this study were collected in a motorway segment of the Lombardia Region(north of Italy)for an exposure assessment research on road paving workers.The evaluation was performed using a metrological approach based on petrographic and mineralogical analyses in order to reduce the epidemiologic risks and to define the best treatment strategies on waste management with sustainable costs in fulfilment of Council Directive 67/548/EEC(1967)and EC Regulation 1272/2008(2008)(Paglietti et al.,2016).The fibers are generally not broken down to other compounds in the environment,but asbestos hazard could be related to the occurrence of tremolite fiber in road paving arises when natural weathering processes(e.g.,erosion)or human activities(e.g.,continuous passage of motorized vehicles)separate and break down the fibers,which could be lost into the environment as airborne and easily penetrate into the human respiratory tract(Punturo et al.,2019).Despite this,this work is not an epidemiological risk analysis but obtained data could be useful to other specialists to define the exposure risks.
