沥青混凝土路面就地热再生技术在高速公路施工中的应用

通过就地热再生试验路段的实施,对沥青路面回收材料(RAP)进行评价。确定了矿料级配设计、再生剂用量、最佳新沥青用量、新混合掺料量、工艺控制和质量要点,为沥青混土路面就地热再生技术方案的确定提供了依据。     

热再生沥青混合料设计与试验研究

为研究废旧沥青路面材料(RAP)掺量热再生沥青混合料的影响,在分析RAP中旧沥青胶结料及集料的性能参数的基础上,根据老化沥青性能改善的试验,确定了不同RAP掺量下旧沥青、再生剂及新沥青的掺配比例,进而确定了不同RAP掺量下的沥青最佳用量。并对再生沥青混合料的马歇尔设计参数和路用性能进行了试验研究,分析了RAP掺量对再生沥青混合料路用性能的影响。     

温拌再生沥青混合料路用性能研究

温拌再生沥青混合料是由热再生技术与冷再生技术发展而来的新型路面材料,文章通过冻融劈裂试验、低温弯曲试验和车辙试验对不同质量分数(0、10%、20%、30%、40%、50%)的RAP温拌再生沥青混合料的水稳定性能、低温抗裂性能及高温稳定性能进行研究。结果表明,随着RAP掺量的增加,温拌再生沥青混合料的冻融劈裂强度比先增大后减小,并在RAP质量分数为30%时达到最大;RAP质量分数为30%时,温拌再生沥青混合料的低温稳定性最好;随着RAP质量分数的增加,再生沥青混合料的高温稳定性能逐渐变好,当RAP质量分数这超过30%时,所添加的新沥青减少,其很难与废旧沥青更好地渗透互溶,使集料间的骨架结构密实程度变差,高温性能降低,因此初步建议路用温拌再生沥青中RAP材料的质量分数不宜超过30%.     

温再生沥青混合料路用性能研究

为实现回收沥青路面材料(RAP)高掺量、低温度条件下的再生利用,文章在RAP沥青及集料性能分析的基础上,利用3G温拌剂及芳烃油配制温再生剂,分析再生沥青黏温曲线特性及再生沥青混合料空隙率的变化情况,确定拌和、压实温度,对RAP掺量分别为50%、60%和70%的再生沥青混合料进行车辙试验、小梁弯曲试验及冻融劈裂试验,评价其路用性能。研究结果表明:再生剂掺量为8%时,最低拌和及压实温度分别为140℃和118℃;当RAP掺量增加时,再生后的沥青混合料高温稳定性增强,低温稳定性及水稳定性降低;当RAP掺量为50%和60%时,温再生沥青混合料高温稳定性良好,低温稳定性及水稳定性符合规范要求;而当RAP掺量达到70%时,其低温稳定性和水稳定性已不满足规范要求。建议所研发的温再生剂RAP最大掺量为60%,压实最低温度为120℃。     

温拌再生沥青混合料RAP掺量方法及性能研究

文章根据AC-13、AC-20的材料组成,选用合理的RAP掺配方案和掺配方法进行试件成型,并通过冻融劈裂强度、应变能密度和车辙试验,研究不同RAP掺量下温拌再生沥青混合料的水稳定性、低温性能和高温稳定性。结果表明:温拌再生沥青混合料的冻融破裂强度比大于热再生沥青混合料,随着RAP掺量增加,温拌再生沥青混合料的水稳定性先增后降,RAP掺量为40%时冻融破裂强度比达到最大值;温拌再生沥青混合料的低温性能与普通沥青混合料大体处于同一水平;随着RAP掺量增加,温拌再生沥青混合料的高温稳定性能得到提高。     

RAP冷料直投热再生工艺在沥青下面层中的应用

本文结合淮北S101路面施工的实践经验介绍了一种RAP冷料直投工艺,将周边养护项目产生的沥青面层铣刨料在常规拌和站中进行热再生应用,并通过4因素2水平的均匀设计方法对RAP冷料直投后的混合料进行拌和均匀性分析和研究,同时对该工艺下的沥青混合料力学性能进行试验检测,形成了一套在常规拌和站中进行RAP沥青混合料回收料的热再生生产工艺.同时对RAP冷料直投添加系统进行介绍.     

RAP不同掺配比例的再生沥青混合料性能研究

本文依托龙大高速公路大修工程,通过沥青路面回收料(RAP)性状评价、矿料的级配分析、最佳沥青用量的确定、高比例RAP配合比设计与检验等步骤,较系统地研究了用马歇尔设计方法,进行了多个RAP掺量下的路用性能试验。分别进行了车辙试验、浸水马歇尔、冻融劈裂试验、弯曲试验等。分析结果表明,随着旧料掺量的增加,再生沥青混合料的高温性能有所改善;高比例RAP下其水稳性随着RAP掺量的增大变化不大;掺加再生剂后其低温性能有所改善。     

废旧沥青混合料性能分析与评价方法研究

依托昆山市政道路升级改造工程,分别从旧路面材料中回收得到旧沥青和旧集料,系统运用宏观性能测试和微观组成测试,全面分析了旧沥青和旧集料材料性能和组成的变异性,为旧路面材料再生利用再生剂选取和新集料级配设计提供了理论指导依据。     

掺RAP的热再生复合改性橡胶沥青混合料路面技术应用研究

在橡胶沥青混合料中掺入RAP,可实现旧路面混合料与旧轮胎的有效利用。文章依托某高速公路大修项目工程,铣刨回收获得SBS改性沥青混合料AC-13的RAP沥青混合料,通过配合比设计得到热再生复合改性橡胶沥青混合料中橡胶沥青与再生沥青的比例,并结合实体工程验证了掺RAP的热再生复合改性橡胶沥青混合料的路用性能,为今后类似项目的研究和应用提供理论依据。     

热拌再生沥青混合料路用性能影响分析

文章为探究不同因素对热拌再生沥青混合料路用性能的影响及影响程度,选择再生剂掺量、RAP掺量、级配及油石比作为自变量,以动稳定度、构造深度为响应变量,利用正交试验设计进行四因素三水平试验,对每组试验数据进行分析,选择最佳水平组合,并进行常规路用性能试验验证。结果表明：对高温性能影响大小依次为RAP掺量>级配>再生剂掺量>油石比;对抗滑性能影响大小依次为RAP掺量>级配>再生剂掺量>油石比;利用极差、方差、灰关联分析得出响应变量综合最佳因素组合水平为A1B3C3D1,即再生剂掺量为2%、RAP掺量为40%、级配为3^#、油石比为4.4%,并对该水平进行了常规路用性能验证,结果均满足技术要求。     

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。     

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。     

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。     

Comparative life-cycle assessment of conventional (double lane) and non-conventional (turbo and flower) roundabout intersections

This research studied and compared different construction techniques for the road subgrade, embankment and pavement of different types of roundabout intersections in order to assess their environmental sustainability. A Life Cycle Assessment (LCA) was carried out on double lane, turbo- and flower roundabouts.We considered virgin materials and reclaimed asphalt pavement (RAP) for the pavement construction. Also the environmental effects due to in situ lime stabilization of fine-grained soils were assessed in order to reduce the use of virgin material in road subgrades.The use of reclaimed asphalt pavement (RAP) can lead to a significant reduction in pollutant emissions and energy consumption (especially due to the lesser material transport) – though with a slightly different impact according to the different percentages employed – compared to the pavements constructed with virgin materials. The same consideration can be made for fine soils with in situ lime stabilization: on the one hand, the technique allows to improve significantly the mechanical properties of soils which would be otherwise dumped and, on the other, to provide considerable environmental benefits. The life cycle assessment of the pavement was carried out with the help of the PaLATE software (by comparing different maintenance scenarios) while emissions and energy consumption in the use phase at intersections were evaluated by means of closed-form models (to estimate vehicle delays and speeds of vehicles) and the COPERT software.Finally, the generalized costs covered in the whole life cycle of roundabouts (i.e. sum of construction, maintenance and environmental costs) were assessed and associated to the different construction options.     

厂拌热再生技术在江西景鹰高速养护工程中的应用

沥青路面厂拌热再生技术是目前养护工程中较为常用的一种技术手段。本文依托于江西省景鹰高速公路2019年沥青路面提升改造工程中对30%高掺量回收沥青混合料(RAP)厂拌热再生AC-20沥青混合料的应用情况,详细介绍了其施工工艺特点、施工关键参数,并揭示了再生沥青路面质量可能面临的质量风险以应对措施,讨论了施工质量检测的基本方法,以期为同类型工程提供有益的参考。     

沥青路面在绿色公路建设发展中的问题分析及应对措施

2020年12月21日,国务院新闻办公室发布《新时代的中国能源发展》白皮书,清晰勾勒了我国在2060年前实现碳中和的"基本路线图"。而在公路建设领域,我国公路及城市道路路面类型大多为沥青路面,沥青路面在新建、改扩建中所面临的能耗巨大、污染严重、旧料回收等环保问题日渐凸显,引发的环境问题不容小觑。本文通过将传统沥青路面的施工工艺流程与低碳、节能等绿色发展理念进行综合分析,阐明了其发展中所面临的诸多环保问题,并利用SWOT分析法对环保沥青的发展态势进行界定,提出了环保沥青材料在不同内外部环境下发展的应对举措,梳理思考了基于传统工法下几种环保沥青路面的发展路线,借以为科技创新引领绿色公路建设的新发展阶段提供一定参考。     

A comparative study of the emissions by road maintenance works and the disrupted traffic using life cycle assessment and micro-simulation

Life cycle assessment is being accepted by the road industry to measure such key environmental impacts as the energy consumption and carbon footprint of its materials and laying processes. Previous life cycle studies have indicated that the traffic vehicles account for the majority of fuel consumption and emissions from a road. Contractors and road agencies are looking for road maintenance works that have the least overall environmental impact considering both the roadwork itself and the disrupted traffic. We review life cycle assessment studies and describe the development of a model for pavement construction and maintenance, detailing the methodology and data sources. The model is applied to an asphalt pavement rehabilitation project in the UK, and the micro-simulation program VISSIM is used to model the traffic on that road section. The simulation results are fed into a traffic emissions model and emissions from the roadwork and the traffic are compared. The additional fuel consumption and emissions by the traffic during the roadwork are significant. This indicates that traffic management at road maintenance projects should be included in the life cycle assessment analysis of such work.     

再生沥青混合料理论最大相对密度确定方法研究

再生沥青混合料内部孔隙较多,掺入的旧料为沥青与集料裹合物,依据规范现有的计算法与试验法难以确定其理论最大相对密度。基于沥青混合料理论最大相对密度计算法和实测法测定原理,通过新拌不同级配类型的沥青混合料,建立理密计算值与实测值关系系数,以再生沥青混合料实测值计算真实值,修正再生沥青混合料理密计算和试验公式。     

Environmentally appraising different pavement and construction scenarios: A comparative analysis for a typical local road

The aim of this work is to carry out a comparative analysis of environmental impacts for different scenarios of a typical local road. Life Cycle Assessment (LCA) is the modeling tool used to quantify and characterize comparative environmental impacts. In carrying out this specific application of the LCA, different road construction techniques were considered with regards to the whole structure and compared in order to identify the best alternative in terms of environmental sustainability.So far, in fact, typical LCA frameworks of roads have focused on recycled materials for pavement layers only, thus neglecting study of the materials used in the embankment or in the subgrade. In this study, these materials were included too, in order to prove the environmental benefit of using a sustainable technique such as in situ stabilization of fine soils with lime (typically dumped clayey soils) in order to reduce the need for virgin material for embankment and subgrade construction.When using different percentages of recycled materials (such as reclaimed asphalt pavement – RAP) in the bituminous layer or in the foundation, the analysis of the functional unit studied shows a significant reduction of energy consumption and pollutant emissions mainly due to transportation of materials involved, in this way increasing the environmental performance of the road.Another important consideration is that the use of fine soils stabilized with lime “in situ”, instead of dumping it, not only is a good technical solution for improving soil mechanical properties, but it also produces a reduction of energy consumption and of pollutant emissions. It is noticeable that this technique results in a significant reduction of pollutant emissions due the transportation of involved materials, increasing the environmental performance of the road.     

The effect of time on acoustic durability of low noise pavements – The case studies in Poland

The tyre/road noise depends on type and speed of vehicles and on the characteristics of road pavement. Vehicle traffic load and weather conditions lead to significant changes in the characteristics of the materials used to build the wearing course. This applies especially to road pavements with the increased void contents. Clogging of the pores, changes in the characteristics of the binder and the damage to the wearing course influence changes in the acoustic properties of the road pavement over time. The article presents the results of the studies on noise level carried out in 2011 and 2014 by the Statistical Pass-By method (SPB) on porous asphalt concrete (PAC), very thin asphalt concrete (VTAC) and stone mastic asphalt (SMA). The wearing courses with the increased void contents immediately after building constitute a very advantageous solution compared with traditional road pavements (dense asphalt concrete, stone mastic asphalt). However, the unfavourable location of the road with porous wearing course, lack of systematic cleaning of porous layers or inappropriate maintenance methods in winter lead to the loss of the acoustic durability of low-noise pavements within a few years of their exploitation.