就地热再生技术在高速公路沥青路面养护中的应用

就地热再生技术作为我国道路材料回收的一项重要技术,能够将废旧沥青经简单处理后用于损伤路面的修复。基于泉州某高速公路沥青路面就地热再生工程实例,首先通过实地调研研判原有道路工程路面性能,结合混合料回收评价对再生沥青混合料材料进行组成设计;其次对施工所涉及到的各类质量控制要点展开分析;最后对热再生的质量做出检验评价。     

基于材料就地再生的多功能养护车作业工艺及经济效益分析

多功能养护车是完成沥青路面病害快速处置的现代化作业机具,而将路面材料的就地再生利用作为养护车的标准配置是其作业功能的重要拓展,且是道路养护现代化的主要标志之一。探讨路面材料再生工艺及相关技术参数的优化对于保证和提高再生材料的路用质量、降低加热能源消耗和环境保护具有重要的现实意义。     

沥青路面就地热再生技术在高速公路工程中的节能效应分析

沥青路面就地热再生施工技术主要是对沥青旧路面的一种养护新技术,在重新就地加热、耙松、添加外加剂等材料进行复拌,使其恢复原有沥青路面功能的一种循环再生工艺,并在其摊铺的同时,同步进行一层沥青混凝土路面结构层的加铺施工技术,该工艺具有创新性和先进性。我国大量高速公路已进入路面维修期,每年将有数亿吨的废料产生,而绝大多数作为工业垃圾来处理,严重浪费资源,废料排放也会形成土地的占有和污染,采用该技术可代替新路面材料使用的同时,可以减少更多的能源浪费和废气排放,也节省了原路面铣刨、运输设备及材料,大大减低资源耗费,成本效益明显。     

浅谈公路沥青路面的再生

沥青路面在使用一定时间后,出现的路面病害使其整体性能将不能满足路用要求,但作为路用材料仍有很高的利用价值。通过路面再生,可以使其重新满足路用性能要求,既能节省大量资金,也能保护环境、节约建筑材料、有利于废料的处理,实现循环经济发展模式和可持续发展。简单介绍了几种常用的道路再生施工技术,结合青海现有的公路现状及施工机械情况,重点推荐厂拌热再生技术的应用。     

试论沥青路面材料的再生工艺及专用机械设备的发展

沥青混凝土路面是目前国内外道路交通的主要面层结构,而沥青材料的热溶解特性,使沥青混合料能够较为容易地实现再生利用。作为节能减排和固废利用的重要组成部分,沥青混合料再生利用的工程规模及其技术进步也反映了一个国家或地区国民经济的发展和技术进步的总体水平。注重并优化沥青混凝土路面材料的再生工艺,并以符合技术条件的专用设备完成作业是路面材料高质量再生利用的前提和必要条件。     

旧沥青路面现场热再生加铺施工技术

为了研究现场热再生技术,在道路维修中,通过以室内试验为基础,对旧路面原材料进行试验分析,充分利用旧材料,有利于节约造价,提高施工进度,目前得到广泛应用。根据现场施工路面性能分析,热再生从技术上可进行推广。     

沥青路面再生过程中混合料路用特性的恢复分析

沥青路面材料的再生利用是道路交通领域固废利用及节能环保的重点项目。随着我国道路通车里程的快速增加和道路等级的不断提高,路面材料再生的质量要求也更为严格。如何达到相应的技术要求是衡量再生沥青混合料(RAP)性能质量的基本条件。在材料再生过程中,根据旧料中沥青的老化程度及矿料级配的变化等提出新料掺配的量化数据,以及专用机械设备的选取和配套作业工艺,是保证RAP用于道路铺筑质量的前提条件。     

路面热再生技术在养护施工中的推广意义

本文通过对公路养护工程具体施工方式的研究,简明扼要的分析了热再生技术在施工现场的施工方式。大量工程实际经验总结得出,路面的现场热再生技术可以大大提高原有路面沥青材料的利用率,提高经济效益的同时,资源得到了重复利用,且由于热再生技术在施工时,不会对环境造成影响,故而该技术的推广更有利于环保。     

道路软基加固处理设计方案分析

路基工程作为道路工程重要的组成部分,不但是路面的基础,而且还承载着由路面传递下来的行车荷载,是道路与自然地面接触的最基本的部分。以竹屿再生水厂周边路网工程为例,通过分析道路软基设计原则,结合道路沿线地质实际情况,提出了软土路基具体处理推荐方案,确保软基路面平整,延长道路使用寿命。     

泡沫沥青再生料稳定基层在干线公路路面整修工程中的应用研究

在高等级公路路面整修工程中,路面铣刨材料的再生利用一直是人们关注的课题。利用沥青发泡技术,将泡沫沥青与水、水泥和路面铣刨材料混合搅拌,形成性能介于柔性基层与半刚性基层之间的泡沫沥青再生稳定基层混合料,并用于陕西延安境内某干线公路路面整修工程中。实践证明,该基层具有技术指标高,经济效益显著的特点,在该大修工程中应用是可行的。     

Comparison of road freight transport trends in Europe. Coupling and decoupling factors from an Input–Output structural decomposition analysis

Decoupling road freight transport from economic growth has been acknowledged by the European Union as a key means to improving sustainability. It is therefore important to identify both the coupling and decoupling drivers of road freight transport demand in order to determine possible factors that may contribute to reduce road transport in the future without curbing economic development. This research proposes an Input–Output (IO) structural decomposition analysis (SDA) to explain road freight transport in terms of a set of key factors that have strongly influenced road freight demand in recent decades in European countries—such as economic growth, economic structure and the evolution of road transport intensity (including improvements in both supply and transport systems). This methodological approach allows us to quantify and compare their contribution in different European countries to either increase or decrease road freight transport demand. The empirical basis for this analysis is a dataset of nine European countries which have IO tables and road transport data available from 2000 to 2007, comprising data on domestic production, imports and exports as well as tonne-kms for 11 types of commodity classes. The results show that, as a whole, aggregate road transport demand has grown—driven mainly by economic activity—but this growth has been strongly curbed in some countries by changes in road freight transport intensity and moderately by the dematerialization of the economy. International transport has been also proven to be a key factor driving road freight transport volumes. Moreover, the increased penetration of foreign operators in national haulage markets appears to have reinforced the final decoupling levels observed in some cases.     

Using smartphones as a very low-cost tool for road inventories

Road inventories are a key component in the planning of road networks as they allow for efficient management and a better return on the investment. Current techniques for carrying out road inventories are expensive and entail long planning processes and data postprocessing. Furthermore, these inventories are only useful to those parties interested in designing and building road networks. This study presents a new method for create road inventories based on the use of the latest generation cellular phones, also called smartphones. This paper describes the use of several mobile apps developed for this project that were implemented during the different stages of road inventory process. The results indicate that the data processing speed, its low cost, and the ease of implementation from any type of vehicle validate the proposed procedure as an invaluable tool (1) to do inventories of all types of road networks that are not accessible to cars; (2) to manage the routine maintenance of small road networks; and (3) as a basis for future research projects on road design and outline.     

基于国省道沥青路面的施工技术相关思考与分析

本文主要针对国省道公路沥青道路的施工技术进行分析,从而及时改进现有的道路工程施工工艺,有效提高道路工程施工效率。道路工程作为当前城市建设中的重要内容,对于城市发展有着极为重要的作用。这就需要有关部门能够对此有着足够的重视,确保道路工程可以充分满足城市发展的需要。通过对公路沥青道路相关施工技术的分析,不仅可以实现道路工程施工工艺的改进,还可以提高道路的通过性,进一步减少国省道的拥堵情况。同时,对公路沥青道路施工技术进行分析,还能实现对于道路工程施工质量的控制,有利于道路使用寿命的提高。沥青道路施工技术的改进,对于当前交通运营及物流有着极为重要的作用。     

临时关闭道路以疏导城市道路交通流的可行性分析

文章基于Braess悖论,以单位车辆的平均出行时间为最优目标,以网络道路系统为约束条件,从逆向思维角度建立了通过临时关闭道路引导交通流以缓解城市道路交通拥挤的Narsh均衡非线性规划模型,并以北京二环道路网络为研究对象进行了实例分析。结果表明,在城市道路网中,关闭部分路段并不能明显缓解交通拥堵现状,但可以在不影响路网整体通行时间的条件下改善路网局部拥堵状况。建议城市道路交通临时疏导方案应该根据路网交通流的分布特点和道路通过能力等因素进行制订。     

Study on road section environmental traffic capacity model and algorithm under double constraints

The coordinated development of city traffic and environment is a key research content in traffic field in twenty-first Century. Among them, road section environmental traffic capacity analysis is one of the important research issues. It can provide solid theoretical basis and reliable data support for road network traffic optimization control, road traffic pollution control and city traffic structure optimization. This paper analyzed main factors which impacted environmental traffic capacity from two aspects, including road capacity constraint conditions and road traffic pollution control constraint conditions. Then, road section environmental traffic capacity optimization model was established, and method of improved augmented Lagrange function was used to solve the model. Case study showed that, (1) The environmental traffic capacity optimal model and methodology were effective; (2) In order to ensure road section environmental traffic capacity greater than (or equal to) road capacity, some measures could be taken including adjusting motor vehicle type proportion as well as improving emission characteristics of motor vehicles exhausting pollutants.     

The interaction between road traffic safety and the condition of sewers laid under roads

The main objective of this paper is to show how the service condition of the underground pipeline infrastructure, especially sewage systems, may contribute to road surface failures such as subsidence, bulging and particularly collapse. The analysis was based on CCTV surveys conducted in Poland to investigate the causes of more than a hundred road surface collapse incidents.The method proposed in this paper enables us to determine the risk of road surface collapse as the product of the category of probability of road collapse caused by damaged sewer pipelines and the weighted arithmetic mean category of their consequences.The key conclusions highlight the causes of road collapse incidents, the scale of the hazards, and the benefits resulting from the application of the proposed method to prioritize roads according to the road collapse risk.     

Road pricing: An international perspective

This paper reviews experience with road pricing in Europe and Asia. It considers the objectives of road pricing, and demonstrates that differences in objectives lead to differences in scheme design and performance. It reviews the criteria for design of road pricing systems, and the development of charging structures and technologies to meet those criteria. In particular it discusses the relative merits of pre-determined and congestion-dependent charging structures, and of off-vehicle and on-vehicle charging systems. It assesses the performance of road pricing systems to date, discusses objections to road pricing and demonstrates that the role of road pricing within a wider transport strategy and the use made of the revenue generated, will be important determinants of public acceptability. Finally it assesses the relative merits of alternative approaches to implementation and argues that these will need to pay as much regard to public acceptability as to technical performance.     

The optimal location of a single ring road

Consider a radial road network such that a single ring road is the only connection between the radials. This paper shows that there is, for any fixed origin-destination distribution, a location of the ring road which minimises the impact of radial traffic flow, for almost any criterion used to assess that impact. An optimal ring road has as many relevant trip-ends inside as outside.     

Comprehensive pavement maintenance strategies for road networks through optimal allocation of resources

In order to maintain a growing road infrastructure at some minimum level of service, substantial resources are required on a recurrent basis. Of late, the available resources can no longer meet all the maintenance and rehabilitation demand even in wealthy nations. Hence, there is a need to develop a tool which will optimally allocate these resources in order to keep the road infrastructure as ‘healthy’ as possible. Further, this tool must acknowledge that maintenance needs are not only restricted to structural aspects but also extend to the functional- and safety-related aspects of a road. Here, such a comprehensive optimization tool is developed which when used will optimally allocate resources in order to maintain a healthy (from structural, functional, and safety standpoints) road network. The problem of determining the optimum maintenance and rehabilitation activities for individual road sections is formulated as a linear integer programming problem. Results from a case study using the proposed method show that the suggested maintenance and rehabilitation plans make sense from engineering and economic considerations.     

Joint road toll pricing and capacity development in discrete transport network design problem

The paper demonstrates a method to determine road network improvements that also involve the use of a road toll charge, taking the perspective of the government or authority. A general discrete network design problem with a road toll pricing scheme, to minimize the total travel time under a budget constraint, is proposed. This approach is taken in order to determine the appropriate level of road toll pricing whilst simultaneously addressing the need for capacity. The proposed approach is formulated as a bi-level programming problem. The optimal road capacity improvement and toll level scheme is investigated with respect to the available budget levels and toll revenues.