Mechanical Behavior and Failure Mechanism of Recycled Semi-flexible Pavement Material

The mechanical behavior and failure mechanism of recycled semi-flexible pavement material were investigated by different scales method. The macroscopic mechanical behavior of samples was studied by static and dynamic splitting tensile tests on mechanics testing system(MTS). The mechanical analysis in micro scale was carried out by material image analysis method and finite element analysis system. The strains of recycled semi-flexible pavement material on samples surface and in each phase materials were obtained. The test results reveal that the performance of recovered asphalt binder was the major determinant on the structural stability of recycled semi-flexible pavement material. The asphalt binder with high viscoelasticity could delay the initial cracking time and reduce the residual strain under cyclic loading conditions. The failure possibility order of each phase in recycled semi-flexible pavement material was asphalt binder, reclaimed aggregate, cement paste and virgin aggregate.

The Influential Factors of Semi-Flexible Pavement Cracking Performance

The cracking performance of semi-flexible pavement(SFP) was investigated by using the semi-circular bending(SCB) test in this paper. Thirteen grouting slurries were prepared. The compressive strength of these materials ranges from 3 to 100 MPa. The relationship between the compressive strength of the grouting slurry and the cracking property of SFP was obtained at different loading rates and different temperatures. The peak load, fracture energy(E), flexible index(FI), and cracking resistance index(CRI) were calculated to determine the material performance. The results show that the compressive strength of the grout influences the cracking behavior. With a higher comprehensive strength grouting slurry, the FI value of SFP decreased initially and then increased slightly at 25 ℃ in 50 mm/min. The CRI value decreased at the same time. E values changed just according to the test temperature and loading rate. The damage paths of SFP are different. The damage path of the SFP sample appears as diffuse damage at 1 mm/min at 60 ℃ or clean damage at 50 mm/min at 25 ℃. These findings indicate that there is a correlation between the compressive strength of grouting slurry and SFP cracking behavior. The cracking form is influenced by loading rate and temperature.

Study on Air-Purifying Performance of Semi-Flexible Asphalt Samples Coated with Titanium Dioxide Using Different Methods

Titanium dioxide(TiO_(2))was recently employed to apply onto road surfaces to degrade the harmful compounds from vehicle emissions.However,it remains a challenging task to find a highly compatible pavement type for TiO_(2)application to achieve durable and efficient air-purifying performance.This study proposed to coat TiO_(2)particles onto semi-flexible pavement surface and tried to investigate an optimum coating method.Three coating methods,including direct mixing TiO_(2)(MT)with asphalt mixture,spraying dry TiO_(2)(ST)coating and watersolution-based TiO_(2)(WT)coating on semi-flexible pavement surface.To achieve this objective,semi-flexible samples were prepared to evaluate and compare the performances of three coating methods by employing resistance to wearing,NO removal efficiency tests and residual texture depth tests.It was found that the ST method not only provided better NO degrading efficiency but also improved the resistance to wearing than the other two methods.

Investigation of material composition,design,and performance of open-graded asphalt mixtures for semi-flexible pavement:A comprehensive experimental study

The primary goal of this study is the design and construction of semi-flexible pavement(SFP)mixture in accordance with the engineering and mechanical criteria.This study involves the use of a range of gradation curves,air void contents,cellulose and synthesized fibers,and neat and modified asphalt binders to prepare the open-graded asphalt(OGA)mixtures.To analyze the characteristics of these mixtures,a variety of test,namely binder drainage,semi-circular bending(SCB),Cantabro,wheel tracking,indirect tensile strength(ITS),and permeability tests were conducted.Additionally,to analyze the prepared grouting material,flexural strength,compressive strength,and fluidity tests were conducted.In the final stage,SFP was compared to HMA in terms of engineering characteristics and performance.According to the results,SFP was more resistant to skid,rutting,fire,and moisture damage,while HMA had a better performance in fracture tests,including SCB test.According to the results of the mechanical performance tests conducted on OGA mixtures,the highest and lowest values for air void content to achieve the highest mechanical performance level were 30%-35%and 25%,respectively.Also,based on the laboratory results,it was determined that the required void ratio for constructing OGA mixtures was 24%-26%based on the bitumen type and fibers amount in the mixture.Finally,SFP mixture can be regarded as a viable alternative to common pavements thanks to its high resistance to rutting and moisture damage,long freezing-thawing fatigue life,and adequate fire and skid resistance.

Application of Different HSI Color Models to Detect Fire-Damaged Mortar

To obtain a better understanding of the effect of vehicle fires on rigid pavement,a nondestructive test method utilizing an ordinary digital camera to capture images of mortar at five elevated temperatures was undertaken.These images were then analyzed by“image color-intensity analyzer”software.In image analysis,the RGB color model was the basic system used to represent the color information of images.HSI is a derived-color model that is transformed from an RGB model by formulae.In order to understand more about surface color changes and temperatures after a vehicle fire,various transformation formulae used in different research areas were applied in this study.They were then evaluated to obtain the optimum HSI model for further studies of fire-damaged mortar through the use of image analysis.

改性彩色沥青路面色彩耐久性与抗滑性能研究

为提高彩色沥青路面色彩耐久性并研究其抗滑性能,采用有机硅-聚丙酸酯(silane-modified polyacrylate,SMP)对彩色沥青玛蹄脂碎石混合料(color stone mastic asphalt,CSMA)和彩色开级配抗滑表层(color open graded friction course,COGFC)2种混合料改性,借助小型加速加载设备进行对彩色沥青路面进行色彩耐久性评价,并通过三维扫描仪进行路面纹理信息采集,分析路面三维参数与其抗滑性能之间的关系。结果表明,SMP改性剂可有效提高CSMA、COGFC两种混合料的抗磨耗能力,提升彩色沥青色彩耐久性;CSMA及COGFC路面抗滑性能受到不同三维参数的影响,路面的摩擦系数模型由各自相关因子控制,增加路面暴露的集料数量和使用尖角集料能使彩色沥青路面的抗滑性能得到提升。

隧道入口段不同颜色路面照明亮度试验对比研究

为了缓解“黑洞效应”对行车安全的不利影响,采用现场测量试验和仿真模拟相结合的方法,研究隧道入口段彩色路面对其照明亮度的影响规律。研究结果表明:不同颜色彩色路面对隧道入口段整体环境的亮度均造成不同程度的提升,其中黄色路面提升效果最明显;隧道入口段高压钠灯提供的环境、路面亮度均比LED灯高;布灯间距对亮度有显著影响,但其增加并未与彩色路面亮度提升成比例关系。研究结果可为高速公路隧道工程的明色化路面设计提供参考。

彩色透水混凝土路面铺装技术在公园工程中的应用

该文将率先介绍彩色透水混凝土路面铺装技术的运用优势,再通过专业的研究与调查,并以某公园工程为例,详细阐述该技术在工程项目中的应用过程,内容包括明确施工操作流程、铺设模板、浇筑混凝土、表面处理及路面养护等,然后借助对混凝土路面的合理规划,探索出改善该施工技术的有效措施,有效增强公园工程路面铺装质量,提升公园内部的美观性、生态性。

ULTC温拌彩色沥青混合料的温拌特性与路用性能研究

为了促进彩色沥青路面的发展,利用等空隙率法确定了ULTC温拌彩色沥青混合料的压实温度,并测试了不同击实温度下的稳定度和流值,分析其温拌特性;对ULTC温拌彩色沥青混合料的高温抗车辙性能、低温抗裂性能和水稳定性进行了测试,并实地铺筑了ULTC温拌彩色沥青试验路。研究结果表明:基于等空隙率法的ULTC温拌彩色沥青的最小击实温度为112℃,在同等条件下,热拌彩色沥青混合料的动稳定度大于温拌彩色沥青混合料,流值小,在实际施工时建议增加养生时间;ULTC温拌彩色沥青混合料的高温性能、低温性能和水稳定性均满足规范要求,试验效果优异,实现了温拌技术和彩色沥青技术的结合。

彩色路面用胶结料的研究

介绍一种用于彩色路面的浅色胶结料的研制机理，并分析了影响该胶结料性能的主要因素．所研制出的胶结料与国外同类产品性能相当，兼具道路沥青的粘结性、柔韧性、抗水性以及与集料的粘附性等工程性质性能，在弹性、韧性方面略胜一筹．

彩色路面铺装技术及发展

介绍国内外彩色路面的发展概况、彩色路面的种类、混合料的设计方法及彩色沥青路面的施工工艺,对美化公共社区、点缀城市建筑、园林建筑,促进道路交通安全和美化空间环境领域发挥着重要作用,同时也有利于提高人们对彩色路面的认识。

彩色路面反射率和内部温度的室内测试分析

为准确评价彩色路面材料的反射性能,以双辐射传感器为基础,测试了室外路面反射率,分析了太阳入射强度、传感器高度、入射角度、测点周边环境对反射率测试结果的影响;针对反射率室外测试受环境影响显著的问题,开发了反射率和温度的室内测试系统,对6种常见颜色路面材料的反射率和内部温度进行了测试,并与水泥混凝土、沥青混合料进行了对比.结果表明:太阳入射强度、入射角度对路面反射率室外测试影响极大,强度越大、入射角度越大,反射率测试结果越大;红、黄、蓝、绿4种彩色路面材料的反射率为20%~25%,高于开级配沥青混合料5.8%、密级配沥青混合料5.4%、多孔水泥混凝土16%,略低于密实水泥混凝土32%的反射率;相同辐射条件下,彩色路面材料内部温度普遍低于沥青混合料和多孔水泥混凝土,绿色路面材料具有最佳的降温效果.

彩色沥青路面施工工艺分析

简述了彩色沥青路面的主要特点,介绍了彩色沥青路面施工中沥青胶结料、骨料、彩色颜料和填料的选择及彩色沥青混合料配合比的确定,从混合料的搅拌、运输、摊铺等方面论述了彩色沥青路面的施工工艺,指出了其应用中存在的问题,可为彩色沥青路面的应用和推广提供参考和借鉴。

彩色路面环境下隧道视觉诱导性评价

为提高彩色路面环境下隧道行车安全性,构建视觉诱导仿真及眼动实验平台,获取注视和扫视行为的眼动参数,在此基础上,提出注视点分布的莫兰指数、扫视时间加权的扫视幅度和基于瞳孔面积变化率的不舒适时间比例等3个彩色路面环境下隧道视觉诱导性评价指标模型,进而给出基于K-means聚类的视觉诱导性评价方法.最后利用黄、红、绿、蓝、灰、白和黑等7种路面颜色色系,进行实例隧道视觉诱导性评价,并用基于语义差别法的主观评价进行成果验证.结果表明:在提升隧道视觉诱导性方面,黄、红色系路面较优,灰、黑色系路面较差,而绿、蓝、白色系路面根据色彩红绿蓝(RGB)数值呈现一定随机优劣性;该评价技术具有一定的有效性,有助于优选隧道路面颜色,提高驾驶舒适性.

公路隧道入口彩色路面设计现状与分析

公路隧道入口处彩色路面的合理铺设对提高视觉警示、保证驾驶安全有重要意义。从公路隧道入口处的交通特性出发,通过大量调研总结了目前隧道入口常见的彩色路面铺设型式,根据速度过渡需求,考虑驾驶知觉-行为模型、透视原理和闪现率原理给出了彩色路面铺设位置、长度以及条纹间距等参数的设计建议,并从亮度过渡角度提出了增大安全距离和设计方案理论验证两种考量方式。最后,从隧道入口处彩色路面的铺设需求出发,讨论了当前隧道入口彩色路面设计面临的主要问题,以期为彩色路面的设计与进一步的研究提供参考。

彩色反射式沥青路面涂层的路用性能

为提高沥青路面的高温稳定性,缓解城市热岛效应,研发了一种彩色反射式沥青路面涂层.首先确定了涂层各原材料用量及制备工艺,然后试验分析了不同颜色涂层的降温效果,最后测试了涂层对路面表面功能的影响,并提出改善措施.结果表明:当反射填料TiO_2与成膜基料的体积比为2.8%时,降温效果最优;从经济和降温效果的角度考虑,推荐红色、绿色以及黄色的填料与成膜基料的体积比分别为2.7%,2.6%和3.2%;为改善涂层的抗滑和耐磨耗性能,可在涂层中部铺撒撒布量为0.48~0.50 kg·m^(-2)的机制砂,并在涂料中加入其质量30%的轻质碳酸钙.

色彩与铺装——澳门城市景观中的海韵

分析澳门城市色彩和地面铺装形成的文脉,认为在制定保护澳门传统景观的原则和开发内容时,应加强城市色彩与铺装的设计,延续地中海风情的传统特色。

浅析运用彩色路面改善高速公路交通安全

阐述彩色路面对道路交通安全的促进作用,分析彩色路面在改善色彩环境、提高交通安全及疏导交通方面的适用性,结合实例分析高速公路事故多发点,提出利用彩色路面提高高速公路交通安全性的建议。

彩色沥青路面耐久性探讨(英文)

结合某城市BRT彩色沥青路面工程项目,在室内试验评价的基础上,探讨胶结料和其它组成材料的性能要求和适宜的掺量,并提出彩色沥青混凝土参考的技术要求,希望得以改善彩色沥青路面的耐久性。

城市道路沥青路面养护技术应用研究

目前,我国城市道路沥青路面养护工作正面临新理念、新技术、新材料和新设备等方面的发展和革新,根据我国城市道路沥青路面的养护现状、特点和需求,分析归纳了在生态环保和经济理念下的现代养护技术类型,研究了不同寿命阶段和不同病害程度下各类养护技术的特点及在西安市的应用实施效果,最后研究提出了未来城市道路沥青路面养护技术的发展新趋势。