Fatigue damage analysis of epoxy asphalt pavement for steel bridges considering coupled effects of heavy load and temperature variations

To investigate the fatigue damage of epoxy asphalt pavement(EAP)under a heavy load and a d temperature load,the load-figure of the heavy load on the steel bridge deck pavement(SBDP)was simulated first,and the temperature distribution of SBDP during the temperature-fall period in winter was also calculated.Secondly,t e moving heavy load coupled W t the most unfavorable temperatre load was applied to the SBDP,and the tensile stress on the top of SBDP was calculated.Finally,the fatigue damage of EAP was evaluated considering the extreme situation of heavily overloaded and severe environments.The results show that botte heavy load and the temperature load during t e temperature-fall period c n increase the tensile stress on the top of SBDP significantly.In the exteme situation of heavily overloaded and severe environments,a fatigue crack is easily generated,and thus the SBDP should avoid t e coupling effects of the heavy loadand the temperature load in winter.

Research on the Evaluation System of Epoxy Asphalt Steel Deck Pavement Distress Condition

Epoxy asphalt concrete has been one of the mainstream technology of steel deck pavement in China. But little specification about evaluation system for its distress condition has been researched and maintenance was still unsystematic. The section weight coefficient of different distress is proposed by analyzing the applicability of the “Highway Performance Assessment Standards”. Indexes mainly including SDPCI PDR and PCR are presented to evaluate its distress condition. The evaluation system and maintenance plan decision tree were recommended which can assist scientific maintenance of epoxy asphalt steel deck pavement.

Control of Pavement-Surface Temperature-Rise Using Recycled Materials

High temperatures of the asphalt concrete pavements in summer contribute to the heat island phenomenon in the urban areas. The effective cool-pavement technologies are sought to mitigate the pavement environment. In this paper, developed heat-reflective pavements are constructed from open-graded asphalt concrete, in which voids in the upper part of the pavement are filled with a cement mortar, containing recycled materials as a fine aggregate. The recycled materials used in this study are： crushed oyster shells, roof tile debris, pottery debris, glass cullet, crushed escallops and coral sand. The temperature reduction of the pavement surfaces at an open site is measured in the summer. The results show that the maximum surface temperature of the pavements falls by approximately 8-10 ℃ compared to the asphalt concrete pavement. Furthermore, it is found that the temperature reduction is mainly due to the increased solar radiation reflectance of the pavement surface.

Theoretical Development and Engineering Practice of Pavements in China

This paper presents a comprehensive review of historical theory development and current construction practice of pavement engineering in China. Mechanical models, design guides, construction techniques, evaluation methods and maintenance standards are elaborated for Portland cement concrete （PCC） pavements methodology among pavements of rural highways, urban roads and asphalt concrete （AC） pavements. Differences in design and airport fields are discussed based on service requirements. Lessons and experiences based on the past 20 years＇ construction practice and pavement performance are summarized. Current research areas in pavement engineering associated with unconventional geological and/or landscaping in China＇s highway construction and national strategic plan for pavement engineering are also covered.

Surface texture and friction characteristics of diamond-ground concrete and asphalt pavements

Recently, diamond grinding has gained increasing attention as pavement preservation treatment to restore desired surface characteristics, particularly friction. Compared to other pavement preservation treatments such as surface overlays and high friction surface treat- ments, diamond grinding may cost less, save construction time, or require minimum maintenance. Diamond grinding produces longitudinal, continuous, and line-type texture that contains corrugations with evenly spaced ridges. The improved surface texture will immediately enhance pavement surface friction and reduce the possibility of hydroplaning in rainy weather. However, little information has been documented on the texture charac- teristics and long-term friction performance of diamond-ground pavements. A field evalu- ation was conducted to examine the surface texture and friction characteristics in diamond- ground concrete and asphalt pavements by the authors. Five pavement test sections, including two diamond-ground concrete pavements, one diamond-ground concrete bridge deck, one diamond-ground asphalt pavement, and one transversely tined concrete pave- ment, were selected for evaluation. Laser scanner testing was performed to capture both macro and microtexture profiles. Locked wheel testing was performed to measure the fric- tion numbers. The test results were examined and compared so as to evaluate two performances, after construction and long-term friction performance of diamond-ground pavements. It was found that longitudinal diamond grinding can provide durable, satisfactory surface friction performance for both concrete and asphalt pavements.

Dynamic response of concrete pavement structure with asphalt isolating layer under moving loads

A three-dimensional finite element model （3D FEM） is built using ABAQUS to analyze the dynamic response of a concrete pavement structure with an asphalt isolating layer under moving loads. The 3D model is prepared and validated in the state of no asphalt isolating layer. Stress and deflection at the critical load position are calculated by changing thickness, modulus of isolating layer and the combination between the isolating layer and concrete slab. Analysis result shows that the stress and deflection of the concrete slab increase with the increase of thickness. The stress and deflection of the concrete slab decrease with the increase of combination between the isolating layer and concrete slab. The influence of changing the isolating layer modulus to the stress and deflection of the concrete slab is not significant. From the results, asphalt isolating layer design is suggested in concrete pavement.

Experimental evaluation of asphalt mixtures with emerging additives against cracking and moisture damage

The objective of this study was to evaluate and recommend an asphalt mixture design with emerging additive technologies that would provide superior performance against asphalt concrete(AC)stripping and cracking.To achieve this objective,a laboratory test program was developed to evaluate the use of nanomaterials(nanoclay and graphene nanoplatelet),an emerging anti-stripping agent(adhere),and warm-mix asphalt technologies(ZycoTherm,Sasobit,and EvoTherm).Two mix types were evaluated,which were a stone-matrix asphalt(SMA)and a dense-graded binder mix.In addition,the modified Lottman test(AASHTO T 283)and the indirect tensile asphalt cracking test(IDEAL-CT)test were used as performance indicators of moisture damage resistance and cracking susceptibility.Results were analyzed statistically to identify and quantify the effects of the design variables and selected additives on the performance,moisture damage resistance,and durability of asphalt mixes.Based on the cracking test results,a superior cracking resistance performance was observed with ZycoTherm,irrespective of the mix type.Adhere had the lowest average cracking indices for both mix types,which suggest that it would not perform as well as the other additives in terms of cracking resistance.Overall,SMA mixes displayed greater cracking resistance than the dense-graded mixtures,which may have been the result of the reclaimed asphalt pavement(RAP)material used in the dense-graded mix and its lower asphalt binder content.In terms of moisture resistance,both nanomaterials(graphene nanoplatelet and nanoclay)did not perform well as they did not meet the minimum required tensile strength ratio(TSR)criterion(>0.80).In addition,nanomaterials showed the lowest TSR values in both mix types suggesting that their effectiveness against moisture-induced damage may not be as good as warm-mix additives.On the other hand,warm-mix additives were expected to show enhanced performance in terms of moisture resistance as compared to the other additives evaluated in this study.

高速公路SMA沥青混凝土路面施工技术分析

近年来随着交通流量的增加及车辆荷载的加重,传统沥青混凝土材料在耐久性方面逐渐显现出不足,容易出现车辙和裂缝等问题,SMA(Stone Mastic Asphalt)沥青混凝土应运而生。源自欧洲的SMA技术已在全球范围内得到广泛应用,核心在于通过改性沥青与优化骨料结构,显著提升了混合料的高温稳定性、抗滑性及抗老化能力。随着交通工程技术的不断发展及施工工艺的进步,SMA沥青混凝土在提升道路性能、延长使用寿命及降低维护成本方面展现出了显著的优势,这些特性使SMA沥青混凝土成为应对现代交通需求及环境挑战的关键解决方案。

Effects of accelerated loading on the stress response and rutting of pavements

In order to assess the difference in performance of pavements under conventional loading and accelerated loading,in this paper,based on the characteristics of pavement strain recovery in accelerated pavement tests(APTs),we define accelerated loading and conventional loading in pavement permanent deformation research.The finite element method is then used to establish a flexible contact model between tire and asphalt pavement.By using simulation,the difference in dynamic stress and rutting of a pavement under the two different loadings is studied.It is discovered that if the APT forms an accelerated loading effect,the pavement will produce deeper rutting under the same axle loading cycle.

基于路面横向力系数下沥青混凝土路面抗滑性能检测方法研究

为了解决公路沥青混凝土路面抗滑性能检测问题,提出了一种基于路面横向力系数测试车的沥青混凝土路面抗滑性能检测方法。该测试车能够装载所有用于抗滑性能检测的设备,并通过供水模块在路面上喷洒水分以湿润路面,为抗滑性能检测环境做准备。在湿润路面后,检测模块利用拉力传感器采集横向力数据,然后通过数据采集处理模块对横向力系数进行分析。最后,结合横向力系数评定标准就能够判断公路沥青混凝土路面的抗滑性能级别。这种方法不仅能够提供准确的结果,对公路沥青混凝土路面的抗滑性能评估还具有重要意义。

探地雷达+注浆技术在公路养护中的应用

沥青混凝土路面具有诸多优点,被广泛应用于各等级公路中。在沥青混凝土路面使用过程中,由于其材料的特点,比较容易发生因为干缩以及温缩引起的开裂病害。沥青混凝土路面一旦开裂,地表水会渗入基层和路基,若长期未得到有效的治理,有可能导致基层强度降低、路基被掏空等更为严重的病害。这类病害最简单的治理方法是开挖路基和路面结构层,并逐层填筑至路面,但这种方法耗时长,需中断交通。除此之外,还可以采用注浆的方法对路基和基层进行加固,再重新施做路面即可恢复通车运营,且施工期间可不中断交通,施工速度非常快。

水泥混凝土路面沥青加铺层病害分析及预防性养护技术研究

随着运营年限增长,水泥混凝土路面会出现不同程度的破损,工程中常采用加铺沥青面层的方式对破损水泥混凝土路面进行修补。依托某水泥混凝土路面沥青加铺层养护工程,对沥青加铺层常见病害及其成因进行分析,并对预防性养护技术在沥青加铺层中的应用进行研究。结果表明:反射裂缝与车辙是沥青加铺层中最常见的病害,采用裂缝填补及微表处技术能够很好地控制沥青加铺层病害发展。

界面糙化对刚柔复合式路面剪切强度的影响

为解决刚柔复合式路面层间易出现滑移、剪切破坏的问题,以刚柔复合式路面层间构造为研究对象,研究采用嵌石构造层间界面对复合式路面层间剪切强度的影响。碎石粒径分别为2.36~4.75 mm、4.75~9.5 mm、9.5~13.2 mm,每种粒径下碎石的撒布面积设置为25%、50%及75%,嵌入深度为其粒径的2/5~3/5,利用自制的斜剪夹具,通过室内试验研究了三种碎石粒径下,各粒径对应三种碎石撒布面积时的复合试件层间剪切强度的大小。试验结果表明:(1)刚柔复合式路面层间剪切强度随着碎石粒径的增大而增大;(2)在三种撒布粒径对应的25%、50%、75%的撒布面积下,层间剪切强度随着撒布面积的增大而增大。

旧水泥混凝土路面沥青铺装层反射裂缝疲劳断裂分析

针对旧水泥混凝土路面沥青铺装层容易产生反射裂缝的特点,采用断裂力学理论,建立了5层体系平面应变模型,对各种荷载作用下不同层间结合状态和路面结构参数的应力强度因子进行了计算分析,并对常用防止反射裂缝措施进行了效果比较。结果表明:层间粘结状态对裂缝扩展的影响较大,土工格栅的防止反射裂缝效果相对较好。

公路工程施工中的沥青混凝土路面施工技术分析

现阶段,大部分公路都选用了沥青混凝土作为路面材料,为了提升这种路面的稳定性和安全性,需要采取合适的施工技术。本文对沥青混凝土路面的优点进行了总结归纳,详细分析了沥青混凝土路面的拌合、运输以及摊铺等施工技术,从两个方面提出了提高沥青混凝土施工效果的方法,希望能为后续公路工程施工提供有价值的参考内容。

高速公路沥青混凝土路面检测技术研究

为提高公路沥青混凝土路面的施工质量,加强路面检测结果的精准性,文章对高速公路沥青混凝土路面检测技术方法进行研究,结合路面平整度、路面弯沉、路面压实度、路面抗滑和路面厚度等方面梳理路面检测的具体内容,阐述检测技术的应用方法与操作要点。最后结合沥青混凝土路面检测技术在实践中常见的问题,提出相应的改进措施。上述技术措施的应用有助于发挥路面检测技术的优势,严格控制沥青混凝土路面施工质量。

基于XFEM的再生复合路面反射裂缝扩展研究

为了探究裂缝扩展路径及在不同条件下的扩展规律,该文基于ABAQUS软件中扩展有限元方法(extended finite element method,XFEM)模拟分析沥青混凝土半圆弯曲断裂试验中的裂缝扩展规律。通过对比他人试验及数值模型数据,验证了基于XFEM的有限元模型分析裂缝扩展的有效性。此外,该文建立干法油石分离再生复合路面二维模型,研究模型中施工缝宽度、预埋裂缝长度、偏转角及预设位置对裂缝尖端应力影响,结果表明尖端应力随着裂缝长度、偏转角增加而增大,而随着施工缝宽度增大呈现先减小后增大趋势,随着偏移距离变大则先增大后减小。该文研究结果有助于复合路面反射裂缝定量分析与表征,为复合路面设计及后期养护提供了参考与依据。

公路工程中沥青混凝土摊铺技术分析

公路工程的沥青路面摊铺施工技术在现代交通建设中扮演着至关重要的角色。随着高速公路建设进程的加速和交通需求的不断增长,对道路的质量和安全性要求也日益提高。因此,有效地应用沥青路面摊铺施工技术成为确保道路质量、延长使用寿命以及提升交通运输效率的关键。首先对沥青路面的组成及结构进行介绍,其次具体介绍公路沥青混凝土摊铺施工中摊铺机参数的设置措施,并分析摊铺施工技术的要点,希望能对该技术的应用有所帮助。

山区公路沥青混凝土路面养护病害处治技术分析

随着交通建设的不断发展,在山区公路养护工作中,沥青混凝土路面的病害处治技术至关重要。针对山区公路沥青混凝土路面的特点,系统地总结了病害处治的关键技术和方法,包括病害检测、修复材料选择、修复工艺等方面的内容。通过实地调研和案例分析,验证了该技术的可行性和有效性,为山区公路沥青混凝土路面养护提供了可靠的技术支撑。

沥青路面检查井周边平整度施工质量控制

沥青路面检查井作为路面的一部分,但其与其他结构不连续,在动荷载作用下,井周易发生破坏,致使路面平整度不足,影响城市道路行车舒适性,甚至影响行车安全。检查井返修率高、难度大、成本高,需局部封闭交通。现以泰州市高港区高港大道改扩建工程为例,介绍沥青路面检查井周边平整度施工工艺。其成果可为同类型的工程施工提供借鉴和参考。