In order to reduce the disease risk stemming from asphalt concrete pavement and ensure the safety of road operation,we should pay attention to the structural design of long-life asphalt pavement,strengthen the selecti...In order to reduce the disease risk stemming from asphalt concrete pavement and ensure the safety of road operation,we should pay attention to the structural design of long-life asphalt pavement,strengthen the selection of long-term pavement materials,scientifically set the pavement mechanical performance indexes based on the calculation results of pavement structure thickness combination and modulus combination,and ensure the stability and durability of road pavement structure through the real-time establishment of three-dimensional finite element calculation model,as well as the integrated design that takes into consideration the aspects of road subgrade,semi-rigid base and asphalt layer.展开更多
The ability of a pavement structure in carrying out its function reduces in line with the increase of traffic load, especially if there are overloaded heavy vehicle passing through the road. This study was done to kno...The ability of a pavement structure in carrying out its function reduces in line with the increase of traffic load, especially if there are overloaded heavy vehicle passing through the road. This study was done to know the effect of overloading vehicles on the road pavement and remaining service life of the pavement. In this study, the service life of pavement due to overloaded vehicles was analyzed using the AASHTO 1993. In Narayanghat-Mugling road the composition of traffic seems to be 83.76% heavy vehicles, 9.18% medium vehicle and 7.05% light vehicle. For the direction of Narayanghat-Mugling, the pavement service life might be reduced by 59.90% due to overloading condition, while for the opposite direction, the service life would not reduced caused by the same factor. The impact of overload conditions on the road pavement showed premature failure;that is, a condition which the damage reduced the life of roads before the design life of the road is reached. From the results, it can be concluded that overloaded vehicles on the road are very influential to the reduction in pavement service life. Therefore, it is expected that road users to comply with existing regulations in the conduct of transportation. As overloading is increasing, it has to be controlled by rules and regulations with penalty to control the overloading. So fines must be associated with intensified enforcement when considered in further strategy. Regular monitoring, inspection and enforcement are the effective ways to control overloading. Use of technology (Automatic overloading information system) may be the effective way to control the overloading.展开更多
In Greece more than 60,000 tn End of Life Tires are stockpiled every year often uncontrollable, causing severe environmental and other socio-economic negative impacts. Studies up to date are focused mainly on mechanic...In Greece more than 60,000 tn End of Life Tires are stockpiled every year often uncontrollable, causing severe environmental and other socio-economic negative impacts. Studies up to date are focused mainly on mechanical and physical characteristics of rubberized mixtures (based on cement, asphalt or soil) in which tire rubber is used either as alternative to natural aggregates or as additive. However, effect of tire rubber on noise reduction in rubberized bituminous layers, which is the main topic of present paper, has not been widely studied. In particular, this research paper is dealing with a sustainable use of tire rubber in asphalt pavement, leading to its generated noise reduction. An experimental pilot application has been conducted in the frame of a European Research Project, which has been implemented in a heavy traffic road section, cited outside Lamia city of Greece, (Vasilikon Street). The upper surface layer of the pavement has been made of rubberized bituminous mixture, produced by the wet process. Rheological characteristics of rubberized bitumen as well as basic properties of the implemented, rubberized bituminous mixture are presented. Moreover, measurements of noise level, deriving from vehicles’ motion, under operational conditions took place at the road section right after its implementation as well as after 8 months of its operation, while all data are presented in details. Results of the measurements on conventional and modified pavement sections are compared, certifying that rubberized asphalt layers can be not only environmentally friendly—since a category of solid wastes (worn automobile tires) is utilized—but also, addition of tire rubber particles in bituminous binder provides up to 3dB noise reducing bituminous mixtures and pavements, noise reduction that remains even after 8 months of road section’s operation.展开更多
For an effective thermoplastic pavement marking replacement strategy, the rate at which the marking’s retro-reflectivity deteriorates in service must be well established in order to avoid re-stripping that is too soo...For an effective thermoplastic pavement marking replacement strategy, the rate at which the marking’s retro-reflectivity deteriorates in service must be well established in order to avoid re-stripping that is too soon or too late. Against this background, this paper undertook a review of models that deal with degradation of thermoplastic pavement markings under different traffic and environmental conditions in order to establish service life and the terminal retro-reflectivity levels that have informed re-striping. Service life in the context of this paper is the time taken for a newly-installed marking to degrade to some minimum retro-reflectivity level below which motorists would find it difficult to navigate on the carriageway under night-time and poor visibility conditions. It was established that the minimum retro-reflectivity requiring re-stripping intervention reported varied, although commonly-adopted values tended to range from 50 mcd/m2/lx to 150 mcd/m2/lx. A number of empirical models, based on site specific conditions, have been developed by researchers using field data, to estimate marking retro-reflectivity at any time since placement. Whereas some of the models used time as the only independent variable, others used a combination of time, traffic level and a few other parameters to estimate retro-reflectivity. Even though degradation of marking retro-reflectivity is a reflection, among other things of material degeneration impacted by environmental and service conditions, almost all the models reviewed failed to consider environmental factors. Additionally, for some of the models, non-inclusion of the initial retro-reflectivity level and their generally low coefficient of determination statistic erode the confidence in their reliability.展开更多
文摘In order to reduce the disease risk stemming from asphalt concrete pavement and ensure the safety of road operation,we should pay attention to the structural design of long-life asphalt pavement,strengthen the selection of long-term pavement materials,scientifically set the pavement mechanical performance indexes based on the calculation results of pavement structure thickness combination and modulus combination,and ensure the stability and durability of road pavement structure through the real-time establishment of three-dimensional finite element calculation model,as well as the integrated design that takes into consideration the aspects of road subgrade,semi-rigid base and asphalt layer.
文摘The ability of a pavement structure in carrying out its function reduces in line with the increase of traffic load, especially if there are overloaded heavy vehicle passing through the road. This study was done to know the effect of overloading vehicles on the road pavement and remaining service life of the pavement. In this study, the service life of pavement due to overloaded vehicles was analyzed using the AASHTO 1993. In Narayanghat-Mugling road the composition of traffic seems to be 83.76% heavy vehicles, 9.18% medium vehicle and 7.05% light vehicle. For the direction of Narayanghat-Mugling, the pavement service life might be reduced by 59.90% due to overloading condition, while for the opposite direction, the service life would not reduced caused by the same factor. The impact of overload conditions on the road pavement showed premature failure;that is, a condition which the damage reduced the life of roads before the design life of the road is reached. From the results, it can be concluded that overloaded vehicles on the road are very influential to the reduction in pavement service life. Therefore, it is expected that road users to comply with existing regulations in the conduct of transportation. As overloading is increasing, it has to be controlled by rules and regulations with penalty to control the overloading. So fines must be associated with intensified enforcement when considered in further strategy. Regular monitoring, inspection and enforcement are the effective ways to control overloading. Use of technology (Automatic overloading information system) may be the effective way to control the overloading.
文摘In Greece more than 60,000 tn End of Life Tires are stockpiled every year often uncontrollable, causing severe environmental and other socio-economic negative impacts. Studies up to date are focused mainly on mechanical and physical characteristics of rubberized mixtures (based on cement, asphalt or soil) in which tire rubber is used either as alternative to natural aggregates or as additive. However, effect of tire rubber on noise reduction in rubberized bituminous layers, which is the main topic of present paper, has not been widely studied. In particular, this research paper is dealing with a sustainable use of tire rubber in asphalt pavement, leading to its generated noise reduction. An experimental pilot application has been conducted in the frame of a European Research Project, which has been implemented in a heavy traffic road section, cited outside Lamia city of Greece, (Vasilikon Street). The upper surface layer of the pavement has been made of rubberized bituminous mixture, produced by the wet process. Rheological characteristics of rubberized bitumen as well as basic properties of the implemented, rubberized bituminous mixture are presented. Moreover, measurements of noise level, deriving from vehicles’ motion, under operational conditions took place at the road section right after its implementation as well as after 8 months of its operation, while all data are presented in details. Results of the measurements on conventional and modified pavement sections are compared, certifying that rubberized asphalt layers can be not only environmentally friendly—since a category of solid wastes (worn automobile tires) is utilized—but also, addition of tire rubber particles in bituminous binder provides up to 3dB noise reducing bituminous mixtures and pavements, noise reduction that remains even after 8 months of road section’s operation.
文摘For an effective thermoplastic pavement marking replacement strategy, the rate at which the marking’s retro-reflectivity deteriorates in service must be well established in order to avoid re-stripping that is too soon or too late. Against this background, this paper undertook a review of models that deal with degradation of thermoplastic pavement markings under different traffic and environmental conditions in order to establish service life and the terminal retro-reflectivity levels that have informed re-striping. Service life in the context of this paper is the time taken for a newly-installed marking to degrade to some minimum retro-reflectivity level below which motorists would find it difficult to navigate on the carriageway under night-time and poor visibility conditions. It was established that the minimum retro-reflectivity requiring re-stripping intervention reported varied, although commonly-adopted values tended to range from 50 mcd/m2/lx to 150 mcd/m2/lx. A number of empirical models, based on site specific conditions, have been developed by researchers using field data, to estimate marking retro-reflectivity at any time since placement. Whereas some of the models used time as the only independent variable, others used a combination of time, traffic level and a few other parameters to estimate retro-reflectivity. Even though degradation of marking retro-reflectivity is a reflection, among other things of material degeneration impacted by environmental and service conditions, almost all the models reviewed failed to consider environmental factors. Additionally, for some of the models, non-inclusion of the initial retro-reflectivity level and their generally low coefficient of determination statistic erode the confidence in their reliability.
