Condition indices for rigid pavements: A comparative analysis of state DOTs using Michigan PMS data

Pavement infrastructure is vital in providing services and links between various sectors of society. Therefore, thepreservation and maintenance of these roads are critical to attaining a pavement network in good conditionthroughout its service life. Various performance indicators like the international roughness index (IRI), pavementcondition index (PCI), and present serviceability rating (PSR) have been used by the state department of transportation (DOT) and highway agencies for evaluating pavement surface conditions and planning future maintenance strategies. Limited data availability, multiple distresses depending on region, lack of correlation of thesecondition indices to maintenance strategies, and data collection limitations pose a challenge for applying theseindices to local conditions. This paper compares condition indices of different states for rigid pavements. Further,using a specific condition index for local conditions is also highlighted. For this purpose, five states and theircorresponding condition indices were evaluated and compared to the Michigan DOT distress index (DI). Thesestates include Virginia, Minnesota, North Dakota, Louisiana, and Oregon. The corresponding distresses of eachcondition index were converted to make them compatible with the MDOT DI. This study used the MDOT'spavement management system (PMS) database to evaluate each condition index for 433 rigid pavement sections.Each distress index was plotted against MDOT DI and compared using a paired t-test. Results show that thecondition indices of Virginia and Minnesota are comparable to DI in terms of the Spearman correlation value. Thet-test results show that except for Virgina, condition indices from other states statistically differ from DI.Therefore, one can't use those directly for local conditions in Michigan. This paper presents the evaluation anddata requirements for each condition index and its impact on selecting a maintenance treatment.

STUDY ON THE FOUNDATION MODULUS OF ELASTIC TWO-LAYERED SYSTEM UNDER RIGID PAVEMENT SLAB

Based on the hypothesis of elastic two-layered foundation system under in-finite slab with known values of thicknesses of various layers and slab modulus,a programADMODE for evaluating foundation modulus is worked out by putting the inverse com-putation idea for moduli of various layers of foundation into an optimization problem.The validities of the theory and program have been checked and verified by taboratorytest.Besides,the foundation modulus have also been computed with this program by usingthe data obtained from Tai-Zhou experimental road.Through regression analyses,theempirical formulas for computing the increasing multiples of the moduli of subgrade andbase course are presented.

Review on dynamic analysis of road pavements under moving vehicles and plane strain conditions

This paper reviews works on the dynamic analysis of flexible and rigid pavements under moving vehicles on the basis of continuum-based plane strain models and linear theories.The purpose of this review is to provide in-formation about the existing works on the subject,critically discuss them and make suggestions for further research.The reviewed papers are presented on the basis of the various models for pavement-vehicle systems and the various methods for dynamically analyzing these systems.Flexible pavements are modeled by a homogeneous or layered half-plane with isotropic or anisotropic and linear elastic,viscoelastic or poroelastic material behavior.Rigid pavements are modeled by a beam or plate on a homogeneous or layered half-plane with material properties like the ones for flexible pavements.The vehicles are modeled as concentrated or distributed over a finite area loads moving with constant or time dependent speed.The above pavement-vehicle models are dynamically analyzed by analytical,analytical/numerical or purely numerical methods working in the time or frequency domain.Representative examples are presented to illustrate the models and methods of analysis,demonstrate their merits and assess the effects of the various parameters on pavement response.The paper closes with con-clusions and suggestions for further research in the area.The significance of this research effort has to do with the presentation of the existing literature on the subject in a critical and easy to understand way with the aid of representative examples and the identification of new research areas.

Finite element modeling of environmental effects on rigid pavement deformation

In this study, finite element （FE）-based primary pavement response models are employed for investigating the early-age deformation characteristics of jointed plain concrete pavements （JPCP） under environmental effects. The FE-based ISLAB （two-and-one-half-dimensional） and EverFE （three-dimensional） software were used to conduct the response analysis. Sensitivity analyses of input parameters used in ISLAB and EverFE were conducted based on field and laboratory test data collected from instrumented pavements on highway US-34 near Burlington, Iowa. Based on the combination of input parameters and equivalent temperatures established from preliminary studies, FE analyses were performed and compared with the field measurements. Comparisons between field measured and computed deformations showed that both FE programs could produce reasonably accurate estimates of actual slab deformations due to environmental effects using the equivalent temperature difference concept.

Field cracking performance of airfield rigid pavements

This paper discusses cracking in airport pavements as studied in Construction Cycle 6 of testing carried out at the National Airport Pavement Testing Facility by the Federal Aviation Administration. Pavements of three different flexural strengths as well as two different subgrades, a soft bituminous layer and a more rigid layer known as econocrete, were tested. In addition to this, cracking near two types of isolated transition joints, a reinforced edge joint and a thickened edge joint, was considered. The pavement sections were tested using a moving load simulating that of an aircraft. It has been determined that the degree of cracking was reduced as the flexural strength of the pavement was increased and that fewer cracks formed over the econocrete base than over the bituminous base. In addition, the thickened edge transition joint was more effective in preventing cracking at the edges compared to the reinforced edge joint.

刚柔复合式路面结构与材料及发展趋势

刚柔复合式路面作为一种耐久性路面结构,广泛应用于重载交通、特殊地质条件、桥隧铺装等工程。为进一步推动耐久性刚柔复合式路面的应用,明确研究中的关键问题及发展方向,该文综述了国内外刚柔复合式路面的相关研究进展。在梳理刚柔复合式路面结构设计理论及施工技术的基础上,首先阐述了刚柔复合式路面的结构力学行为特征,分析了沥青面层和刚性基层的荷载应力、温度应力及其交互影响,刚性基层上的沥青面层一方面直接承受荷载和环境作用,另一方面可以改善下卧结构层的应力场和温度场,是影响刚柔复合式路面服役性能及使用寿命的关键;明确了刚柔复合式路面的病害主要出现在沥青面层,由于沥青面层与刚性基层之间的模量差异巨大,刚性基层上的沥青面层更倾向于产生压剪破坏,刚性基层的开裂以及刚‒柔层间的结合状态对沥青路面的性能也有着显著影响;最后,分别从沥青面层抗剪、基层板整体性、刚‒柔层间结合3个方面归纳了刚柔复合式路面性能的提升技术。基于刚柔复合式路面的结构力学特性,开展结构‒高性能材料一体化设计是提升刚柔复合式路面使用性能和耐久性的有效途径。

移动荷载下道路病害的弯沉盆特性

移动荷载作用下道路弯沉盆蕴含路基、路面的病害信息,充分利用移动弯沉盆信息开展道路病害快速无损检测受到行业重要关注。该文通过分析道路病害的弯沉盆特性,为移动弯沉车开发道路病害检测方法提供技术参考。首先建立半刚性基层沥青路面有限元模型,通过设置不同类型和程度的病害有限元模型,分析在移动荷载作用下路表弯沉盆的连续变化情况。结果表明:荷载移动到病害区域时,各病害模型中路表弯沉盆的中心弯沉值均会变大;路面结构层出现横向裂缝时,弯沉盆的形状会发生明显变化,贯通性横向裂缝对弯沉盆形状的影响最明显;基层与底基层局部松散对弯沉盆形状的影响比面层松散对弯沉盆的影响更明显;土基顶部出现空洞时,弯沉盆形状变化不明显;路基唧泥病害会严重影响路表弯沉盆形状与大小。

半刚性基层沥青路面病害及其防治研究

为了提高半刚性基层沥青路面的建设水平,文章依托某国道一级公路,分析了路面反射裂缝、车辙等病害的产生原因,通过ABAQUS软件建立计算模型,分析了反射裂缝的受力和车辙的变形规律,同时提出了采取加铺玻纤格栅、确定基层预切缝间距等措施来处治路面病害,研究成果可为类似项目提供借鉴。

半刚性基层开裂的沥青路面承载力响应特性

为研究半刚性基层开裂对沥青路面承载力响应特性的影响,采用ABAQUS软件建立具有不同形态基层反射裂缝的沥青路面三维模型,研究其在载荷作用下的路面承载力响应特性,揭示响应机理。研究结果表明:反射裂缝越长,路面承载力响应越大。反射裂缝在贯穿路表前后,承载力响应由弱至强发生激增,反射裂缝只在一定宽度范围内影响承载力响应。给出了处治基层反射裂缝的指导建议,即结合现行方案,注意区分反射裂缝和面层裂缝,限制反射裂缝的发展。从长度、宽度、结构层位3个角度分析了反射裂缝对承载力响应特性的影响,仿真结果与现场实测结果相吻合,为研究半刚性基层沥青路面的承载力响应特性提供参考。

高速隧道刚性基础路面加铺应力吸收层力学特性研究

橡胶沥青应力吸收层常用于水泥混凝土路面改造工程,因其优异的路面结构层间处治性能,而具有广阔的应用前景。本文以厦蓉高速青新隧道为工程背景,基于ANSYS软件建立有限元模型,并施加最不利偏载工况进行计算分析,探讨了加铺应力吸收层前后路面的力学性能,并对沥青铺装层厚度、沥青铺装层弹性模量、应力吸收层厚度等参数对路面力学性能影响进行了分析。

基于非对称设计的高密度电法观测装置研究

高密度电阻率法需要较好的接地条件来保证地电场的建立和测量,当遇到刚性路面等不良接地条件时,部分电极无法插入地下,将导致标准观测装置的数据缺失,影响成像质量。为此,本文提出了一种快速的观测装置设计方法,依靠缺失数据记录点的空间位置,使用非对称四极电极排列进行补充。数值模拟表明,该方法对温纳、斯伦贝谢和偶极—偶极装置的成像效果均有明显提升,且设计时间仅为秒级。该方法被成功应用到宁波堤防工程现场探测中,降低了机动车道对数据质量的影响,准确定位了堤防位置。

基于截尾分布的永久路面结构可靠度分析

为建立基于实测参数变异范围的永久路面结构可靠度分析方法,首先基于概率等效原则和逆变换法建立参数“有界”性的双侧截尾分布随机数抽样方法;然后选取现行沥青路面设计规范中面层、基层和路基结构的验算指标建立极限状态方程并开发多指标可靠度计算程序,将分析结果与理论分布随机变量可靠度程序对比;最后结合实测参数变异性水平,使用建立的可靠度分析方法评估京德高速永久路面结构的工后可靠度。结果表明:截尾分布更符合工程参数的真实分布,计算的可靠度更准确;中等交通荷载等级下,京德高速的路面结构可靠度为95.2%~98.7%;在累计当量轴次失效点后,永久路面结构面层、基层和路基的可靠度值均随轴次的增大而减小,且荷载越大,可靠度值下降速率越快,可靠度也越低。

固废基半刚性路面动力响应研究

为了探究固废基半刚性基层沥青路面的路用性能,以110国道包头北绕城段公路为依托,建立了基于实测参数的半刚性路面结构3D有限元模型,对其在波动荷载作用下的力学响应进行了分析,并将有限元模拟结果与容许数据进行了对比分析。结果表明:基于固废利用的半刚性路面,其结构层在波动荷载下的应力、应变远小于材料容许值,满足规范基本要求。研究结果可为同类路面的材料配比、结构组合、参数实测提供理论依据,促进固废材料的广泛应用。

泡沫沥青复合式冷再生混合料组成设计与性能评价

文中通过发泡试验确定了泡沫沥青的最佳发泡条件,采用马歇尔试验确定了RAP和RAI不同掺配比例下泡沫沥青的最佳掺量,测试分析了泡沫沥青复合式冷再生混合料的抗压强度、抗拉强度、水稳定性和动态模量等性能.结果表明:在发泡温度为160℃,发泡用水量为2.9%的条件下,沥青发泡效果最优;在最佳发泡条件下,RAP掺量为0%、20%、40%的三种方案对应的泡沫沥青最佳掺量分别为3.4%、3.1%、2.9%,此时,三种方案均有较好的抗压、抗拉、水稳定性,并且随着泡沫沥青冷再生混合料中RAP掺量的增加,柔化程度与抗拉性能均逐渐增大,但抗压性能与水稳定性能均有所降低.

半刚性路面基层养生期实验研究

文章介绍了一种实验方法,用于评估半刚性路面基层养生期的效果。该方法采用实验室模拟养生环境,通过观测和分析基层材料在不同养生时间下的力学性能、收缩性能和耐久性等指标,量化养生期对基层性能的影响。实验结果表明,适当的养生期对提高半刚性路面基层的各项性能具有显著作用。文章研究内容为优化基层材料设计和施工工艺提供了理论依据。

基于感知应变的刚性道面结构强度评价方法

刚性道面结构强度实时准确评价,是保障机场设施耐久与适航安全的重要工作,其中决定性因素为基层顶面反应模量K。依托西南某国际机场智能跑道系统,采集C类飞机通过事件下的刚性道面板动态应变响应状态;通过HWD弯沉测试获取道面初始结构参数,建立机场刚性道面9块板足尺有限元模型,通过考虑轮迹偏移和基层顶面反应模量K值对道面板中监测点位动态应变的影响,建立K值与动态应变响应峰值期望ε值的函数关系曲线;采用桥渡原理,补偿机场刚性道面仿真模型与实际结构之间的偏差,将模拟仿真函数关系转换至实际感知函数关系,基于实测感知应变实时评价基层顶面反应模量。在此基础上,采用当量单轮荷载法建立机场道面强度评价指标PCN值与K值的关系,最终实现基于感知应变的刚性道面结构强度实时评价。

聚丙烯防裂基布在扩建道路中的应用研究

为研究聚丙烯长丝防裂基布在高速公路路面的抗反射裂缝效果,文中通过车辆荷载试验、芯样剪切强度等试验对沥青混凝土路面面层防裂效果进行研究及评价。结果表明铺设聚丙烯长丝抗裂基布的样块裂缝贯穿时经历的加载次数是无抗裂基布样块的2.65倍,铺设聚丙烯长丝抗裂基布的芯样剪切强度比没有抗裂基布的提高46%以上。在新建半刚性基层沥青混凝土路面和旧路面接缝处,加铺聚丙烯长丝抗裂基布可以延缓路面反射裂缝的产生,提高道路工程的安全可靠性。

半刚性基层裂缝微创注浆耐久性评价——以江苏省内宁杭等高速为例

在高速公路沥青路面的养护工程中,常规手段难以彻底解决路面结构内部的隐性病害问题。微创注浆技术因其技术优势,逐渐被用于这类病害的修复。然而现在研究方向聚焦于注浆材料的研发和施工工艺,对于注浆技术耐久性评价关注较少。鉴于耐久性直接影响技术的使用效果和寿命延长,开展耐久性评价显得尤为重要。采用室内试验和实地路面跟踪观测两种方法评估半刚性基层裂缝注浆的效果。结果表明:养生28 d、90 d、1 a的不同龄期无侧限抗压强度恢复率分别为70.4%、70.0%、68.6%;养生7 d、28 d、90 d、1 a的地推直剪试验剪切强度分别为0.75、1.25、1.21、0.90 MPa;养生28 d冻融循环2次劈裂强度值为5.2 MPa。表明半刚性基层裂缝微创注浆并经长期使用后,无侧限抗压强度值、剪切强度值仍保持较好的水平。根据实体工程持续跟踪观测,芯样完整性高、浆液饱满、强度值未明显衰减。

刚柔复合式路面水泥混凝土板接缝传荷能力影响因素研究

文章旨在评估刚柔复合式路面中水泥混凝土板接缝传荷能力的影响因素,以提高路面性能和延长使用寿命。通过有限元模拟,探究模量变化、沥青层厚度、弹性模量及厚度变对水泥混凝土板接缝传荷能力产生的影响。研究发现,适当调整这些参数能显著提升接缝的传荷效率。基于实验数据,提出了适用于刚柔复合式路面的接缝传荷性能控制指标,为路面检测和维护提供了新标准,有助于优化路面设计和施工,确保行车安全。

超载状态下半刚性基层沥青路面力学响应分析

基于弹性层状体系理论,应用BISAR软件对标准轴载和不同超载状态下半刚性基层沥青路面的力学响应进行分析,主要指标包括路表弯沉、行车方向水平拉应力和沥青面层竖向压应力。研究结果表明,超载状态下路面结构的力学响应值大幅度增长,将导致路面使用性能降低,缩短使用寿命。应加大超载运输治理力度,保障路面正常运营。