低碳交通新理念下温拌沥青混合料的设计与施工

温拌沥青混合料的性能非常接近于热拌沥青混合料,在低碳交通的新理念下,温拌沥青混合料体现了它低排放、低污染的优点,本文基于两种温拌添加剂(固、液各一种),采用空隙率等效和压实特性对其降温效果进行了评价,并对设计的沥青混合料路用性能进行了试验研究。结果表明,两种温拌材料具有不同程度的降温效果,对混合料性能也有一定影响。相关研究方法可为温拌沥青混合料的设计提供借鉴。采用两种温拌剂进行了现场实施,应用结果表明,固体类温拌剂更适合高寒地区沥青路面工程特点,并提出了相应的最低施工温度。     

温拌剂在沥青路面低温施工中应用的可行性探析

文章针对低温下沥青混合料的施工特点,分析了应用温拌沥青混合料的主要技术思路及作用。通过对不同温拌剂作用原理及效果的分析,探究了温拌沥青混合料施工中遇到的主要问题,提出在验证温拌沥青混合料路用性能的前提下,以控制温拌剂质量、验证沥青性能、保证施工温度等为技术措施,保障温拌剂在路面施工中的良好应用。     

城市隧道温拌阻燃复合改性沥青铺装技术研究

出于隧道施工与运营期的环保和安全性考虑,本文对城市隧道采用温拌、阻燃特殊铺装技术的适用条件进行了探讨,并对温拌阻燃复合改性沥青技术进行了试验研究。结果表明:掺加沥青质量0.5%的表面活性温拌液可有效降低施工温度达20℃,优化了隧道铺装施工环境,收到节能环保效果;掺加沥青质量10%的阻燃剂可提高沥青氧指数至23%,大大降低隧道内火灾发生几率,提高隧道施工及运营期的安全性;温拌与阻燃复合改性兼容性佳,在不影响沥青混合料路用性能的前提下起到各自应有的效果。     

温-热拌再生剂对再生沥青及其混合料性能的影响研究

为对比研究温拌与热拌再生剂对再生沥青及混合料的性能的影响,文章通过分析不同添加剂对老化沥青性能的恢复,开展室内试验探究了不同再生沥青对其混合料路用性能的影响规律。结果表明:新沥青的掺入对老化沥青性能恢复有显著的作用,温拌再生与热拌再生剂对老化沥青的针入度和软化点恢复效果相近,温拌再生剂可以更有效地恢复老化沥青的延度,同时使再生沥青的黏度低于新沥青;温拌再生剂更大程度地恢复了老化沥青的复数剪切模量,但导致了再生沥青黏弹性比例失调;温拌再生剂对沥青混合料的水稳定性改善高于热拌再生剂,但低温及高温性能略低于热拌再生剂。     

相变材料对温拌沥青混合料路用性能及微观机理的影响

为了有效改善公路交通环境,阐述国内外温拌沥青混合料的研究和发展现状,分析温拌沥青混合料的微观机理,重点研究相变材料对温拌沥青混合料路用性能及微观机理的影响,并针对此提出一些有效对策,为相关部门提供参考,同时还可以为我国道路的设计与施工提供参考。     

温拌阻燃沥青混凝土技术性能研究

文章以某高速公路隧道路面工程为依托,采用AC-13改性沥青混合料,通过对比温拌阻燃沥青混凝土与热拌SBS改性沥青混凝土的水稳定性、高温稳定性、低温抗裂性、劈裂强度、抗剪强度、抗冲刷性能、耐腐蚀性能,研究了温拌阻燃沥青混凝土的技术性能。结果表明:温拌剂和阻燃剂对沥青混凝土的常规路用性能影响较小,两种混凝土的高温稳定性、水稳定性、低温抗裂性能差别不大,但温拌阻燃沥青混凝土比热拌沥青混凝土更耐油污腐蚀;高温和浸水会显著降低温拌阻燃沥青混凝土的劈裂强度和抗剪强度。     

Sasobit改性剂对温拌沥青拌合料性能的影响研究

Sasobit是温拌沥青改性技术中一种有效的改性剂,Sasobit温拌沥青混合料具有拌合及压实温度低、和易性好、路用性能优良等特点,被广泛应用于道路工程和桥梁铺装工程中。文章主要研究Sasobit改性剂对温拌沥青拌合料的拌合及压实温度的影响,并选择不同的改性剂添加方式,探讨干拌合湿拌工艺对Sasobit温拌沥青混合料拌合性能的影响。结果表明,Sasobit改性剂可使温拌沥青混合料的拌合温度降低10℃左右,并能够有效降低拌合料压实温度,改善拌合物的和易性,此外湿拌工艺相比干拌工艺对成型温度影响较大,但二者均可达到温拌效果。     

Thiopave温拌改性沥青在重载交通路面工程中的应用研究

文章针对HMA重载交通路面的主要破坏特征,通过对Thiopave改性沥青路用性能的研究,开展了Thiopave温拌改性沥青混合料配合比设计与优化,并将其应用于试验路铺筑中。通过效果评估分析,发现用Thiopave温拌改性沥青处治重载交通特殊路段,具有在技术上、经济上和环境上的可行性,同时还具有施工简单、不增加施工成本等优点。     

RAP掺量对Sasobit温拌再生沥青混合料性能的影响分析

为研究RAP掺量对Sasobit温拌再生沥青混合料路用性能的影响,文章在Sasobit掺量为3%,RAP掺量分别为20%、30%、40%的条件下成型沥青混合料试件,测定了各项路用性能参数,对温拌再生沥青混合料的路用性能进行研究,并将不同的RAP掺量视为不同维度,采用各路用性能指标与RAP掺量为0时的欧几里得距离评价了Sasobit温拌再生沥青混合料性能对RAP掺量敏感性,提出了基于欧几里得距离的Sasobit温拌再生沥青混合料极限RAP掺量确定方法。结果表明:RAP的掺入增强了混合料的高温性能,降低了混合料的低温性能和水稳定性能,且当RAP掺量20%时,混合料的动稳定度指标显著增大;当RAP掺量30%时,浸水残留稳定度比衰减较大。由此,提出了采用欧几里得距离确定极限RAP掺量的方法,且当Sasobit用量为3%时,RAP的最大掺量宜≤24%。     

温拌再生沥青混合料水稳性研究

温拌再生沥青混合料是一种新型的节能环保路用材料,但其水稳性能不良严重影响其推广与应用。文章采用转移率试验、红外光谱试验分析活化剂对混合料新旧沥青界面的宏观作用效果及其微观作用机理;同时通过冻融劈裂试验研究活化剂对温拌再生沥青混合料水稳性的影响。研究结果表明:与未添加活化剂相比,添加0.1%活化剂的RAP旧沥青转移率由19.73%提高至48.33%;红外光谱分析表明活化剂与旧沥青发生了加成缩合等化学反应;与普通温拌再生沥青混合料相比,添加0.1%活化剂的温拌再生沥青混合料冻融劈裂强度比明显增大,TSR值由59.55%上升至89.75%,进一步表明活化剂对温拌再生沥青混合料水稳性有明显的改善作用。     

沥青路面抗滑性能影响因素识别研究进展

沥青路面作为公路建设的重要内容,其抗滑性能是道路安全问题的核心,探究其影响因素可以为提高路面抗滑性能提供依据。国内外学者对此做了大量研究,也取得了相应的进展。本文对国内外的研究成果进行了系统的归纳总结,将公路沥青路面抗滑性能影响因素分为了沥青混合料的材料特性、环境因素、车辆特性3个主要方面,其中在沥青混合料的材料特性方面,研究认为集料的结构特性与混合料配合比对抗滑性的影响较大;环境因素方面,研究认为温度对于抗滑性的影响较大;车辆特性对抗滑性的影响方面,研究认为主要体现在轮胎特性与荷载方面。此外随着行车速度的增加,路面的抗滑性能呈现降低趋势。     

旧沥青路面现场热再生技术的应用现状

文章介绍了沥青路面现场热再生技术以及在国内外的应用情况、施工工艺以及质量控制等。分析了不同旧料掺配率的再生沥青混合料的性能，提出现有指标以及施工规范不适用于评价现场热再生沥青路面的问题。因此，尽快制定出沥青路面再生利用技术的设计规范和验收评定标准，有利于再生混合料生产和施工的规范化。     

新型废胶粉改性沥青混合料的路用性能试验研究

通过在沥青中掺入不同量的废旧橡胶粉进行沥青改性,以解决我国道路沥青温度敏感性大的问题,进行了橡胶粉改性沥青性能试验,橡胶粉改性沥青混合料的路用性能试验,确定掺入橡胶粉剂量在15%为最佳,通过试验数据表明,沥青混合料的各项路用性能得到明显改善。     

岩沥青对沥青混合料路用性能的影响研究

文章针对印尼产Buton岩沥青的特性,对不同掺量的岩沥青改性沥青混合料和复合改性沥青混合料SMA-10的水稳定性、高温稳定性和低温抗裂性分别进行室内对比试验研究。结果表明,随着岩沥青掺量的增加,岩沥青改性混合料和复合改性沥青混合料的水稳定性、高温稳定性和低温抗裂性等路用性都能改善明显,其中,以岩沥青掺量为沥青混合料质量的3％时,综合路用性能改善效果最好。     

沥青混合料集料的分形级配研究

沥青混合料具有复杂的微观结构,是一种多级多层次的复合材料体系。文章采用分形几何的方法对沥青混合料的级配进行研究,并以AC-20和SMA-20为例,在现行规范级配曲线范围内选取了6组级配,通过回归分析和计算,得到了每种级配集料的分形维数。     

Use of infrared thermography for assessing HMA paving and compaction

The assessment of paving and compaction temperatures effect on Hot Mix Asphalt (HMA) properties has been the subject of various researches. The present study aims to build upon these researches, by investigating the effectiveness and practicality of infrared thermography (IRT) as an emerging technology to assess HMA paving and compaction. For this purpose a field experiment was performed using a thermographic system to investigate the impact of the temperature in a paving project where two different types of HMA were used. The recorded mat surface temperatures are used effectively for the identification of temperature differentials, as well the detection of pavement defects. In addition, density-growth curves are developed for the specific mixtures and compaction pattern being used. IRT data is further analyzed for the development of simple HMA cooling models, providing a quick and efficient means to estimate the compaction time. More details and discussion are outlined in the paper.     

温拌薄层罩面在景鹰高速公路养护工程中的应用与实践

为研究温拌沥青混合料薄层罩面施工技术,依托江西省景鹰高速公路沥青路面养护工程,优化原材料的选取,总结施工技术要点,并探究实验路段的实际施工效果,按照《公路工程沥青及沥青混合料试验规程》(JTG E20-2011),对已铺筑完成的施工路段进行摩擦系数、渗水系数和构造深度检测,结果显然,罩面施工后沥青路面的使用功能得到较好的恢复与改善。     

A stochastic optimization approach for the selection of reflective cracking mitigation techniques

PurposeIn Hot Mix Asphalt (HMA) overlays, the existing cracks in the underlying pavements can propagate upward to the new added overlay and may cause Reflective Cracks (RC). These cracks allow water infiltration to the underlying layers and causes further moisture damage as well as weakening the unbound layers. Over the years, several methods have been developed for mitigating the RCs. This study aims to investigate the current reflective cracking mitigation methods and develop a methodology for the selection of appropriate mitigation technique. The developed model is then applied to a case study in the state of Florida.MethodTo accomplish this goal, a nationwide literature review was conducted to better understand the current in practice methods in the United States. Moreover, a life cycle cost analysis (LCCA) in five different road types was performed to find the annuity of roadway rehabilitation for each of the mitigation methods. The uncertainty in the LCCA results is represented using Exploratory Modeling and Analysis (EMA) method. Then through a Multi Criteria Decision Making (MCDM) model, a stochastic optimization model was developed to find the appropriate reflective cracking mitigation solution under Florida’s climate and road conditions, based on different cost and performance weights.ResultsBased on the available data for the state of Florida, the LCCA results indicate that the annuity of maintaining the roadway with Fabrics and ISAC are lower compared to other methods. However, the results of stochastic optimization model reveal that while looking at the performance and cost at the same time, different methods would be more feasible. For instance, while the cost of the used method does not matter at all and only performance matters, STRATA® is more probable to be the appropriate mitigation technique. The findings of this research are critical for decision makers to better understand the most cost-effective mitigation technique in different conditions.     

The limits of partial life cycle assessment studies in road construction practices: A case study on the use of hydrated lime in Hot Mix Asphalt

Extensive published literature shows that hydrated lime improves Hot Mix Asphalt (HMA) durability. Its impact on the environmental impact of HMA has not been investigated. This paper presents a comparative Life Cycle Assessment (LCA) for the use of HMA without hydrated lime (classical HMA) and with hydrated lime (modified HMA) for the lifetime of a highway. System boundaries cover the life cycle from cradle-to-grave, meaning extraction of raw materials to end of life of the road. The main assumptions were: 1. Lifetime of the road 50 years; 2. Classical HMA with a life span of 10 years, maintenance operations every 10 years; 3. Modified HMA with an increase in the life span by 25%, maintenance operations every 12.5 years. For the lifetime of the road, modified HMA has the lowest environmental footprint compared to classical HMA with the following benefits: 43% less primary total energy consumption resulting in 23% lower emissions of greenhouse gases. Partial LCAs focusing only on the construction and/or maintenance phase should be used with caution since they could lead to wrong decisions if the durability and the maintenance scenarios differ. Sustainable construction technologies should not only consider environmental impact as quantified by LCA, but also economic and social impacts as well. Avoiding maintenance steps means less road works, fewer traffic jams and hence less CO₂ emissions.     

Planning strategies for promoting environmentally suitable pedestrian pavements in cities

This paper examines the relevance of incorporating comprehensive life-cycle environmental data into the design and management of pedestrian pavements to minimize the impact on the built environment. The overall primary energy demand and global warming potential of concrete, asphalt and granite sidewalks are assessed. A design with a long functional lifetime reduces its overall primary energy demand and global warming potential due to lower maintenance and repair requirements. However, long-lived construction solutions do not ensure a lower life-cycle primary energy demand and global warming potential than for shorter-lived designs; these values depend on the environmental suitability of the materials chosen for paving. Asphalt sidewalks reduce long-term global warming potential under exposure conditions where the functional lifetime of the pavements is less than 15 years. In places where it is known that a concrete sidewalk can have a life of at least 40 years, a concrete sidewalk is the best for minimizing both long-term primary energy demand and global warming potential. Granite sidewalks are the largest energy consumers and greenhouse gas contributors.