Texturing and evaluation of concrete pavement surface:A state-of-the-art review

Concrete pavement is accompanied by two major functional properties,namely noise emission and friction,which are closely related to pavement surface texture.While several technologies have been developed to mitigate tirepavement noise and improve driving friction by surface texturization,limited information is available to compare the advantages and disadvantages of different surface textures.In this study,a state-of-the-art and state-of-thepractice review is conducted to investigate the noise reduction and friction improvement technologies for concrete pavement surfaces.The commonly used tests for characterizing the surface texture,skid resistance,and noise emission of concrete pavement were first summarized.Then,the texturing methods for both fresh and hardened concrete pavement surfaces were discussed,and the friction,noise emission and durability performances of various surface textures were compared.It is found that the next generation concrete surface(NGCS)texture generally provides the best noise emission performance and excellent friction properties.The exposed aggregate concrete(EAC)and optimized diamond grinding textures are also promising alternatives.Lastly,the technical parameters for the application of both diamond grinding and diamond grinding&grooving textures were recommended based on the authors'research and practical experience in Germany and the US.This study offers a convenient reference to the pavement researchers and engineers who seek to quickly understand relevant knowledge and choose the most appropriate surface textures for concrete pavements.

Virtual strain loading method for low temperature cohesive failure of asphalt binder

Cohesive failure is one of the primary reasons for low-temperature cracking in asphalt pavements.Understanding the micro-level mechanism is crucial for comprehending cohesive failure behavior.However,previous literature has not fully reported on this aspect.Moreover,there has been insufficient attention given to the correlation between macroscopic and microscopic failures.To address these issues,this study employed molecular dynamics simulation to investigate the low-temperature tensile behavior of asphalt binder.By applying virtual strain,the separation work during asphalt binder tensile failure was calculated.Additionally,a correlation between macroscopic and microscopic tensile behaviors was established.Specifically,a quadrilateral asphalt binder model was generated based on SARA fractions.By applying various combinations of virtual strain loading,the separation work at tensile failure was determined.Furthermore,the impact of strain loading combinations on separation work was analyzed.Normalization was employed to establish the correlation between macroscopic and microscopic tensile behaviors.The results indicated that thermodynamic and classical mechanical indicators validated the reliability of the tetragonal asphalt binder model.The strain loading combination consists of strain rate and loading number.All strain loading combinations exhibited the similar tensile failure characteristic.The critical separation strain was hardly influenced by strain loading combination.However,increasing strain rate significantly enhanced both the maximum traction stress and separation work of the asphalt binder.An increment in the loading number led to a decrease in separation work.The virtual strain combination of 0.5%-80 provided a more accurate representation of the actual asphalt's tensile behavior trend.

内蒙古深季节冻土区公路水热过程的实体工程试验

季节冻土区道路工程冻融病害频繁,路基的水热耦合作用是病害发育的控制因素。为揭示该地区公路路基的水热作用过程,分析其影响因素和变化规律,基于内蒙古深季节冻土区室韦—拉布达林公路实体工程3年的观测数据,分析了沥青路面结构层和路基的冻融规律、含水率变化特征以及水热相互作用过程。观测数据表明,该地区公路路基冻融频繁,面层处的最高、最低温度和融化指数、冻结指数均为最大,其他部位的地温随着路基深度的增加有所减小,路基底部附近的融冻指数比约为天然地表的1.6倍以上。路基的完全冻结时间在150 d左右,且随着运营时间的延长,融化期有所延长。路基内含水率表现出显著的季节交替特性,底基层处的含水率最大,暖季时达到40%左右,基层处的含水率最小,在10%以下,路基体内的含水率在20%~25%。地温与含水率存在显著的线性相关性,水分的波动受温度影响显著。沥青路面的温度梯度和水分通量的统计关系表明,水分通量的变化主要集中在融化期内,且与温度梯度的变化吻合较好,底基层内的水分通量最为活跃,说明温度梯度是水分迁移和聚集的重要驱动力,沥青路面吸热和封水的结构特性是诱发路基下部水分在底基层处聚集的主要原因,提出此类地区道路工程的冻融病害防治需从保温和隔水两方面入手。

温拌橡胶沥青:一种可持续回收利用废旧轮胎橡胶的途径

将废旧轮胎橡胶回收利用为沥青改性剂是建筑可持续路面结构的有效途径。该方法具有提高路面耐久性、减少废旧轮胎处理压力、降低路面噪音等优点。温拌沥青技术可有效降低常规热拌沥青混合料混合和压实时的温度。现有研究表明,将温拌沥青技术与废橡胶改性沥青通过不同的方式结合,可以有效降低沥青混合的施工温度,从而减少橡胶沥青在施工过程中的排放量。本文总结了165篇文献的研究结果,从流变性能、配合比设计、混合料力学性能、实际应用、施工排放以及橡胶沥青与温拌剂的相互作用等方面分析、比较、总结了近年来国内外对温拌橡胶沥青的研究进展。期望本综述能为温拌橡胶沥青的进一步研究,发展及推广应用提供借鉴。

Advanced industrial informatics towards smart,safe and sustainable roads:A state of the art

The road is one of the most important civil infrastructures for serving society,where its service quality and life have direct impacts on the safety and comfort of users.Therefore,road construction,condition detection and monitoring,and timely maintenance are particularly important for engineers.Many engineering applications of industrial informatics approaches,like image processing technology,widely used computer-based algorithms,and advanced sensors,have been initially and gradually applied to roads.This state-of-the-art review first summarized the research on industrial applications of advanced information technologies in recent years,while analyzing and comparing the advantages and disadvantages of each technology.Especially,five topics were focused on road construction,road maintenance with decision strategy,road structure evaluation,smart sensing in the road,and cooperative vehicle infrastructure system.It is expected that advanced industrial informatics can help engineers promote the development of smart,safe,and sustainable roads.

Application of semi-analytical finite element method to analyze the bearing capacity of asphalt pavements under moving loads

便于长期的基础结构财产管理系统，决定人行道的适用的能力是必要的。当前以一种静止方式进行如此的大小是普通的，然而，有静止装载的评估不对应于现实向最近的年里的连续、高的速度大小的一个趋势能被观察。计算程序 SAFEM 与在动人的负担下面评估沥青的动态反应的目的被开发并且基于一个半分析的元素方法。在这个研究工程， SAFEM 与商业有限元素软件 ABAQUS 和领域大小相比验证计算精确性。虽然自称拥有比 ABAQUS 远短的一计算时间， SAFEM 的计算精确性被发现足够高可行。因此， SAFEM 看起来是一条可行途径在动态负担下面决定人行道的动态反应并且是一个有用工具让基础结构政府分析忍受能力的人行道。

Calculation of skid resistance from texture measurements

There is a wide range of routine skid resistance measurement devices on the market. All of them are measuring the friction force between a rubber wheel and the wetted road surface.Common to all of them is that they are relatively complex and costly because generally a truck carrying a large water tank is needed to wet the surface with a defined water layer.Because of the limited amount of water they can carry they are limited in range. Besides that the measurement is depending on factors like water film thickness, temperature,measurement speed, rubber aging, rubber wear and even road evenness and curviness. All of these factors will affect the skid resistance and are difficult to control. We present a concept of contactless skid resistance measurement which is based on optical texture measurement and consists of two components: measurement of the pavement texture by means of an optical measuring system and calculation of the skid resistance based on the measured texture by means of a rubber friction model. The basic assumptions underlying the theoretical approach and the model itself based on the theory of Persson are presented.The concept is applied to a laboratory device called Wehner/Schulze(W/S) machine to prove the theoretical approach. The results are very promising. A strong indication could be provided that skid resistance could be measured without contact in the future.

Approaches for a 3D assessment of pavement evenness data based on 3D vehicle models

Pavements are 3D in their shape.They can be captured in three dimensions by modern road mapping equipment which allows for the assessment of pavement evenness in a more holistic way as opposed to current practice which divides into longitudinal and transversal evenness.It makes sense to use 3D vehicle models to simulate the effects of 3D surface data on certain functional criteria like pavement loading,cargo loading and driving comfort.In order to evaluate the three criteria mentioned two vehicle models have been created:a passenger car used to assess driving comfort and a truck-semitrailer submodel used to assess pavement and cargo loading.The vehicle models and their application to 3D surface data are presented.The results are well in line with existing single-track(planar)models.Their advantage over existing 1D/2D models is demonstrated by the example of driving comfort evaluation.Existing"geometric"limit values for the assessment of longitudinal evenness in terms of the power spectral density could be used to establish corresponding limit values for the dynamic response,i.e.driving comfort,pavement loading and cargo loading.The limit values are well in line with existing limit values based on planar vehicle models.They can be used as guidelines for the proposal of future limit values.The investigations show that the use of 3D vehicle models is an appropriate and meaningful way of assessing 3D evenness data gathered by modern road mapping systems.

Study of the influence of pavement unevenness on the mechanical response of asphalt pavement by means of the finite element method

Pavement unevenness affects the vehicle operating cost, speed, riding comfort, safety,pavement service life and etc. The current mechanistic-empirical(M-E) design procedure of asphalt pavements is based on the computational model of a flat pavement instead of uneven pavement as it is the case in reality. In this paper, a tire-pavement-interaction FE model is developed to investigate the influence of pavement unevenness on the mechanical responses of asphalt pavements. For both winter and summer conditions, the strain at the bottom of the asphalt layer due to the tire load is found to decrease as the wavelength of the unevenness increases. Moreover, the strain is larger at lower speeds and decreases as the speed increases. It is found that the stress levels are higher in summer conditions than under winter conditions for the same pavement irrespective of wavelength. The fatigue life increases with increase in speed of the tire for a pavement and also increases with increase in the wavelength of the pavement unevenness. The results indicate that pavement unevenness significantly influence the mechanical responses of asphalt pavements and thus influences the service life of asphalt pavements. As a result,the current M-E design algorithm of asphalt pavements should be modified to consider the pavement unevenness to allow better design processes for asphalt pavement.

面向未来低碳道路养护的超薄罩面功能性研究综述

Highway maintenance mileage reached 5.25 million kilometers in China by2021.Ultra-thin overlay is one of the most commonly used maintenance technologies,which can significantly enhance the eco-nomic and environmental benefits of pavements.To promote the low-carbon development of ultra-thin overlays,this paper mainly studied the mechanism and influencing factors of several ultra-thin over-lay functions.Firstly,the skid resistance,noise reduction,rutting resistance,and crack resistance of ultra-thin overlays were evaluated.The results indicated that the high-quality aggregates improved the skid and rutting resistance of ultra-thin overlay by 5%-20%.The optimized gradations and modifed binders reduced noise of ultra-thin overlay by 0.4-6.0 dB.The high viscosity modified binders improved the rut-ting resistance of ultra-thin overlay by about 10%-130%.Basalt fiber improved the cracking resistance of ultra-thin overlay by more than 20%.Due to the thinner thickness and better road performance,the performance-based engineering cost of ultra-thin overlay was reduced by about 30%-40%compared with conventional overlays.Secondly,several environ mentally friendly functions of ultra-thin overlay were investigated,including snow melting and deicing,exhaust gas purification and pavement cooling.The lower thickness of ultra-thin overlay was conducive to the diffusion of chloride-based materials to the pavement surface.Therefore,the snow melting effect of self-ice-melting was better.In addition,the ultra-thin overlay mixture containing photocatalytic materials could decompose 20%-50%of the exhaust gas.The colored ultra-thin overlay was able to reduce the temperature of the pavement by up to 8.1C.The temperature difference between the upper and lower surfaces of the ultra-thin overlay containing thermal resistance materials could reach up to 12.8C.In addition,numerous typical global engineering applications of functional ultra-thin overlay were summarized.This review can help better understand the functionality of ultra-thin overlays and promote the realization of future multi-functional and low-carbon road maintenance.

New innovations in pavement materials and engineering:A review on pavement engineering research 2021

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges.In the past 10 years,the pavement infrastructure strongly supports the rapid development of the global social economy.New theories,new methods,new technologies and new materials related to pavement engineering are emerging.Deterioration of pavement infrastructure is a typical multi-physics problem.Because of actual coupled behaviors of traffic and environmental conditions,predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis.In order to summarize the current and determine the future research of pavement engineering,Journal of Traffic and Transportation Engineering(English Edition)has launched a review paper on the topic of"New innovations in pavement materials and engineering:A review on pavement engineering research 2021".Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering,this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world.The content includes asphalt binder performance and modeling,mixture performance and modeling of pavement materials,multi-scale mechanics,green and sustainable pavement,and intelligent pavement.Overall,this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering.

Characterization of road surfacing aggregates based on their mineralogical fingerprint

To ensure the safety of infrastructure users,the long-term skid resistance is a crucial factor and is determined in large by the mineralogical and morphological characteristics of surfacing aggregate.Most studies have investigated these aggregate properties separately without considering the interrelation between one another.The objective of this study is to consider the morphological characteristics as well as the mineralogical fingerprint of aggregate to develop an innovative approach to optimize the aggregate selection process.The investigations are based on 11 different aggregate types with a broad range of mineralogy,commonly used in Germany.The long-term influence of polishing and wearing on the surface aggregate was simulated by means of the Aachen Polishing Machine and the MicroDeval test respectively.To evaluate the impact of these tests,the aggregate shape was characterized by means of an imaging system called Aggregate Image Measurement System while the skid resistance of aggregates was evaluated with the British Pendulum Test.The test results show that the quartz and calcite are the key crystals to determine the anti-wear resistance of aggregates.A correlation between the skid resistance,morphological properties and mineralogy is derived,which proves the mineralogical fingerprint technology is practical for characterization of aggregates used in pavement surface layers.

Preface for the special issue on “Functional pavement materials and characterization”

With the ever increasing demand for the riding quality and long service life of the pavement,more and more researches were focused on the functional pavement both in Europe and China.The Chair and Institute of Highway Engineering at the RWTH Aachen University in cooperation with the Southeast University and the Harbin Institute of Technology,China,launched the 3rd China e Europe Workshop on Functional Pavement in August 6e8,2014,in Aachen,Germany.The workshop attracted more than 120 participants from 10countries and provided 37 high levels of academic reports.