Pavements require maintenance to prevent undue distress or to restore performance; however, pavement maintenance and its impacts do not receive enough attention in many cases, and are either ignored or treated as a lo...Pavements require maintenance to prevent undue distress or to restore performance; however, pavement maintenance and its impacts do not receive enough attention in many cases, and are either ignored or treated as a low priority, Most current maintenance activities have budget issues and only focus on removing deteriorated pavement sections, Deferred pavement maintenance has impacts on the environment and on society, and may thus affect the costs associated with maintenance, A sustain- ability rating tool is a good way to list, explain, and evaluate such impacts, Various sustainahility rating tools have been developed for pavement; however, pavement maintenance has its own features that are different from those of the new construction, expansion, or reconstruction of pavements, This research project reviews nine sustainahility rating tools for pavement, although none of these tools fully describe maintenance features or can he directly applied to evaluate maintenance projects, A new sustainahility rating tool is then developed for pavement maintenance; this new tool can he used to evaluate individual projects and raise public awareness about the importance of pavement mainte- nance, Its details are described, and its use is demonstrated through an example to show the evaluation process and results,展开更多
In order to improve the surface performace of epoxy asphalt pavement （EAP） for steel bridge deck, an epoxy asphalt chip seal （ ECS） covered by a cationic emulsified asphalt fog seal （i. e., fog-sealed chip seal）...In order to improve the surface performace of epoxy asphalt pavement （EAP） for steel bridge deck, an epoxy asphalt chip seal （ ECS） covered by a cationic emulsified asphalt fog seal （i. e., fog-sealed chip seal） isproposed and a laboratory study is conducted to design and evaluate te fog-sealed chip seal. First, the evaluation indices and methods of te chip seal on steel bridge deck pavement were proposed. Secondly, the worst pavement conditions during te maintenance time were simulated by te small traffic load simulation system MMLS3 and the short-term aging test for minimizing the failure probability of chip seal. Finally, the design parameters of fog-sealed chip seal were determined by the experimental analysis and the performance of the designed fog-sealed chip seal was evaluated in thelaboratory. Results indicate that the proposed simulation method of pavement conditions is effective and the maximal load repetitions on the EAPslab specimen are approximately 925 300 times. Moreover, the designed fog-sealedchip sealcan provide a dense surface with sufficient skid resistance,aggregate-asphalt aahesive performance and interlayer shearing resistance.展开更多
The wearing course conditions strongly affect road pavements quality in terms of traffic safety and overall functionality.Surface texture can be considered a very strategic aspect to assess road pavement status,in ord...The wearing course conditions strongly affect road pavements quality in terms of traffic safety and overall functionality.Surface texture can be considered a very strategic aspect to assess road pavement status,in order to predict its degradation and to define an effective maintenance program.Nowadays,common texture assessment approaches are mainly empirical and based on in-situ and/or laboratory direct measurements,thus the quantity and quality of the obtainable information are limited.On the other hand,advanced contactless techniques require expensive and often complicated equipment that can be hardly used in common applications.In this regard,a low budget close-range photogrammetry technique for road pavements 3D surface texture analysis is here proposed.14 areal texture parameters including depth,volume,distribution and feature indicators have been determined by analysing the 3D models.The outcomes have been compared with those found with the traditional volumetric patch and pendulum tests,and a complete pairwise correlation matrix has been obtained.Volume patch test exhibits a high relationship with different volume and height surface texture parameters,while lowcorrelations have been found comparing pendulum test with the intrinsic and statistical indicators.The results and their relationships have been commented in-depth along with proposed further research activities.展开更多
The International Society for Maintenance and Rehabilitation of Transport Infrastructures （iSMARTi）, the National University of Singapore and the Pavement Engineering Society （Singapore） jointly organized the 8th ...The International Society for Maintenance and Rehabilitation of Transport Infrastructures （iSMARTi）, the National University of Singapore and the Pavement Engineering Society （Singapore） jointly organized the 8th International Conference on Maintenance and Rehabilitation of Pavements （MAIREPAV- 8） in Singapore on 27-291uly 2016. The conference covered all aspects of maintenance and rehabilitation of road and airport pavements. Over 200 participants from 32 countries participated in this conference, which featured more than 120 technical presentations and two forums.展开更多
Survey of road cracks in a timely,complete,and accurate way is pivotal to pavement main tenance planning.Motivated by the increasingly heavy task of identifying cracks,research ers have developed extensive crack segme...Survey of road cracks in a timely,complete,and accurate way is pivotal to pavement main tenance planning.Motivated by the increasingly heavy task of identifying cracks,research ers have developed extensive crack segmentation models based on Deep learning(DL)methods with significantly different levels of accuracy,efficiency,and generalizing capac ity.Although many of the models provide satisfying detection performance,why these models work still needs to be determined.The objective of this study is to survey recent advances in automated DL crack recognition and provide evidence for their underlying working mechanism.We first reviewed 54 DL crack recognition methods to summarize critical factors in these models.Then,we conducted a performance evaluation of fourteen famous semantic segmentation models using the quantitative metrics:F-1 score and mIoU.Then,the effective receptive field and class activation map of the included models are visu alized to demonstrate the training results as qualitative evaluation.Based on the literature review and comparison results,larger kernel size,feature fusion,and attention module all contribute to the improvement of model performance.Striking a balance between increas ing the effective receptive field and computational/memory efficiency is the key to design ing DL crack segmentation models.Finally,some potential directions and suggestions for future development are provided,such as developing semi-supervised or unsupervised learning for the high cost of pixel-level labeling.展开更多
Traditional asphalt concrete(AC)and stone matrix asphalt(SMA),which are used as thin asphalt overlays,are common maintenance strategies to enhancing ride quality,skid resistance,and durability.Recently,several studies...Traditional asphalt concrete(AC)and stone matrix asphalt(SMA),which are used as thin asphalt overlays,are common maintenance strategies to enhancing ride quality,skid resistance,and durability.Recently,several studies have used a novel asphalt mixture known as a high-friction thin overlay(HFTO)to improve surface characteristics.However,it remains uncertain whether the laboratory properties of HFTO differ significantly from those of conventional mixtures.This study aims to evaluate the laboratory properties of HFTO mixtures and compare them with those of AC and SMA.Those mixtures with nominal maximum size of 9.5 mm were produced in the laboratory,and performance tests were conducted,including wheel tracking test,low temperature flexural creep test,moisture susceptibility test,Cantabro Abrasion Test,Marshall Test,sand patch test,British pendulum test,and indoor tire-rollingdown test.The results showed that the HFTO exhibited a lower tire/pavement noise than the AC and SMA.Additionally,HFTO had superior high-temperature stability,larger macro texture,and higher skid resistance in comparison to those of AC,but lower than those of SMA.Consequently,HFTO mixtures may be considered a suitable replacement for traditional AC mixtures in regions where skid resistance and noise reduction are concerns.展开更多
文摘Pavements require maintenance to prevent undue distress or to restore performance; however, pavement maintenance and its impacts do not receive enough attention in many cases, and are either ignored or treated as a low priority, Most current maintenance activities have budget issues and only focus on removing deteriorated pavement sections, Deferred pavement maintenance has impacts on the environment and on society, and may thus affect the costs associated with maintenance, A sustain- ability rating tool is a good way to list, explain, and evaluate such impacts, Various sustainahility rating tools have been developed for pavement; however, pavement maintenance has its own features that are different from those of the new construction, expansion, or reconstruction of pavements, This research project reviews nine sustainahility rating tools for pavement, although none of these tools fully describe maintenance features or can he directly applied to evaluate maintenance projects, A new sustainahility rating tool is then developed for pavement maintenance; this new tool can he used to evaluate individual projects and raise public awareness about the importance of pavement mainte- nance, Its details are described, and its use is demonstrated through an example to show the evaluation process and results,
基金The National Natural Science Foundation of China(No.51378122)
文摘In order to improve the surface performace of epoxy asphalt pavement （EAP） for steel bridge deck, an epoxy asphalt chip seal （ ECS） covered by a cationic emulsified asphalt fog seal （i. e., fog-sealed chip seal） isproposed and a laboratory study is conducted to design and evaluate te fog-sealed chip seal. First, the evaluation indices and methods of te chip seal on steel bridge deck pavement were proposed. Secondly, the worst pavement conditions during te maintenance time were simulated by te small traffic load simulation system MMLS3 and the short-term aging test for minimizing the failure probability of chip seal. Finally, the design parameters of fog-sealed chip seal were determined by the experimental analysis and the performance of the designed fog-sealed chip seal was evaluated in thelaboratory. Results indicate that the proposed simulation method of pavement conditions is effective and the maximal load repetitions on the EAPslab specimen are approximately 925 300 times. Moreover, the designed fog-sealedchip sealcan provide a dense surface with sufficient skid resistance,aggregate-asphalt aahesive performance and interlayer shearing resistance.
文摘The wearing course conditions strongly affect road pavements quality in terms of traffic safety and overall functionality.Surface texture can be considered a very strategic aspect to assess road pavement status,in order to predict its degradation and to define an effective maintenance program.Nowadays,common texture assessment approaches are mainly empirical and based on in-situ and/or laboratory direct measurements,thus the quantity and quality of the obtainable information are limited.On the other hand,advanced contactless techniques require expensive and often complicated equipment that can be hardly used in common applications.In this regard,a low budget close-range photogrammetry technique for road pavements 3D surface texture analysis is here proposed.14 areal texture parameters including depth,volume,distribution and feature indicators have been determined by analysing the 3D models.The outcomes have been compared with those found with the traditional volumetric patch and pendulum tests,and a complete pairwise correlation matrix has been obtained.Volume patch test exhibits a high relationship with different volume and height surface texture parameters,while lowcorrelations have been found comparing pendulum test with the intrinsic and statistical indicators.The results and their relationships have been commented in-depth along with proposed further research activities.
文摘The International Society for Maintenance and Rehabilitation of Transport Infrastructures （iSMARTi）, the National University of Singapore and the Pavement Engineering Society （Singapore） jointly organized the 8th International Conference on Maintenance and Rehabilitation of Pavements （MAIREPAV- 8） in Singapore on 27-291uly 2016. The conference covered all aspects of maintenance and rehabilitation of road and airport pavements. Over 200 participants from 32 countries participated in this conference, which featured more than 120 technical presentations and two forums.
基金This study was sponsored by the National Natural Science Foundation of China(No.52008311,No.51878499,No.52178433)the Science and Technology Commission of Shanghai Municipality(No.21ZR1465700)the Fundamental Research Funds for the Central Universities(No.22120200447 and No.22120220120).
文摘Survey of road cracks in a timely,complete,and accurate way is pivotal to pavement main tenance planning.Motivated by the increasingly heavy task of identifying cracks,research ers have developed extensive crack segmentation models based on Deep learning(DL)methods with significantly different levels of accuracy,efficiency,and generalizing capac ity.Although many of the models provide satisfying detection performance,why these models work still needs to be determined.The objective of this study is to survey recent advances in automated DL crack recognition and provide evidence for their underlying working mechanism.We first reviewed 54 DL crack recognition methods to summarize critical factors in these models.Then,we conducted a performance evaluation of fourteen famous semantic segmentation models using the quantitative metrics:F-1 score and mIoU.Then,the effective receptive field and class activation map of the included models are visu alized to demonstrate the training results as qualitative evaluation.Based on the literature review and comparison results,larger kernel size,feature fusion,and attention module all contribute to the improvement of model performance.Striking a balance between increas ing the effective receptive field and computational/memory efficiency is the key to design ing DL crack segmentation models.Finally,some potential directions and suggestions for future development are provided,such as developing semi-supervised or unsupervised learning for the high cost of pixel-level labeling.
基金The authors acknowledge financial support provided by the Natural Science Basic Research Program of Shaanxi(No.2024JCYBMS-309)the Shaanxi Provincial Transportation Science and Technology Project(Nos.19-29K,18-12,and G20-04K).
文摘Traditional asphalt concrete(AC)and stone matrix asphalt(SMA),which are used as thin asphalt overlays,are common maintenance strategies to enhancing ride quality,skid resistance,and durability.Recently,several studies have used a novel asphalt mixture known as a high-friction thin overlay(HFTO)to improve surface characteristics.However,it remains uncertain whether the laboratory properties of HFTO differ significantly from those of conventional mixtures.This study aims to evaluate the laboratory properties of HFTO mixtures and compare them with those of AC and SMA.Those mixtures with nominal maximum size of 9.5 mm were produced in the laboratory,and performance tests were conducted,including wheel tracking test,low temperature flexural creep test,moisture susceptibility test,Cantabro Abrasion Test,Marshall Test,sand patch test,British pendulum test,and indoor tire-rollingdown test.The results showed that the HFTO exhibited a lower tire/pavement noise than the AC and SMA.Additionally,HFTO had superior high-temperature stability,larger macro texture,and higher skid resistance in comparison to those of AC,but lower than those of SMA.Consequently,HFTO mixtures may be considered a suitable replacement for traditional AC mixtures in regions where skid resistance and noise reduction are concerns.
