路面设计原理-01

The Pavement ConceptsTransportation College, Southeast University 东南大学交通学院课程学习的基本要求一．本课程的目的和意义本课程为公路、城市道路机场工程方向的硕士研究生学位课程。

通过本课程的学习，学生应掌握路面设计的基本原理、世界各国使用的主要方法，初步了解本学科前沿动向和学科发展趋势。

Transportation College, Southeast University 东南大学交通学院课程学习的基本要求二．主要参考教材１．Principles ofPavement DesignE.J.Yoder M.W.Witczak （原版及中文版） ２．柔性路面设计理论与方法朱照宏许志鸿同济大学出版社 ３．柔性路面结构设计方法林绣贤人民交通出版社 ４．刚性路面设计 邓学钧陈荣生人民交通出版社5．路面设计原理与方法邓学钧黄晓明人民交通出版社Transportation College, Southeast University东南大学交通学院课程学习的基本要求三．课程计划第一章基本原理 第二章车辆与交通第三章气候与环境 第四章路基材料 第五章沥青路面排水第六章沥青路面应力分析第七章水泥混凝土路面应力分析Transportation College, Southeast University 东南大学交通学院课程学习的基本要求三．课程计划第七章无机结合料稳定材料 第八章沥青混凝土材料 第九章水泥混凝土材料 第十章公路沥青路面设计方法 第十一章公路水泥混凝土路面设计 第十二章机场沥青混凝土道面设计 第十三章机场水泥混凝土道面设计第十四章路面使用品质及路况评定Transportation College, Southeast University东南大学交通学院Pavement RequirementsThe aim of pavement design :most economic pavement thickness andcomposition .Transportation College, Southeast University东南大学交通学院Pavement RequirementsTo achieve this goal,(1)the designer’s knowledge materials ,the traffic , the local environment –and their interactions .Transportation College, Southeast University东南大学交通学院Pavement Requirements(2)The designer’s knowledge level of performance , and what pavement condition .Transportation College, Southeast University 东南大学交通学院Pavement PurposeLoad support . Pavement material is generallystiffer than the material upon which it is placed, thus it assists the in situ material in resisting loads without excessive deformation or cracking.Smoothness . Pavement material can be placed and maintained much smoother than in situ material. This helps improve ride comfort and reduce vehicle operating costs.Drainage . Pavement material and geometric design can effect quick and efficient drainage thus eliminating moisture problems such as mud and ponding (puddles).Transportation College, Southeast University东南大学交通学院Pavement RequirementsSound pavement performance depends on a number of factors:Design –including materials assessment and pavement composition.Construction –to meet design requirements,including tolerances and drainage.Maintenance –to maintain pavement integrity .Transportation College, Southeast University 东南大学交通学院Pavement RequirementsPavement performance Requirements:Strength and Stiffness Stability Durability Roughness Skid resistance NoiseTransportation College, Southeast University东南大学交通学院Safetygood low speed skid resistancegood high speed skid resistance through prevention of hydroplaning conspicuity of road markings low spray generationlow glare and specular reflectionno windscreen breakage from stonesTransportation College, Southeast University 东南大学交通学院Skid resistance measurementSingle locations measured by British portable pendulum testerNetworks tested by SCRIM vehicle and other devicesMeasure wet since this is the critical conditionTransportation College, Southeast University 东南大学交通学院Skid resistancelow speed skid resistance depends on aggregate polishing resistance (m i crotexture)high speed skid resistance depends on above and escape paths for water (m a crotexture)Transportation College, Southeast University 东南大学交通学院Transportation College, Southeast University 东南大学交通学院Transportation College, Southeast University 东南大学交通学院Transportation College, Southeast University 东南大学交通学院Transportation College, Southeast University 东南大学交通学院Road surface textureTransportation College, Southeast University 东南大学交通学院Transportation College, Southeast University东南大学交通学院Transportation College, Southeast University东南大学交通学院After John OliverTransportation College, Southeast University东南大学交通学院After John OliverTransportation College, Southeast University东南大学交通学院Skid resistance英国进行详细的观测给出了指南以事故的概率为依据they are graded according to how “dangerous ”a site is针对不同的交通等级different values given for high and low traffic roadsTransportation College, Southeast University 东南大学交通学院Skid resistance -SFCTransportation College, Southeast University 东南大学交通学院Transportation College, Southeast University东南大学交通学院Skid resistance -SFCSite DescriptionInvestigatory level of SFC 0.300.350.400.450.500.551Traffic lightsTransportation College, Southeast University 东南大学交通学院Skid resistance道路面层抗滑性能抗滑指标:Transportation College, Southeast University 东南大学交通学院Skid resistance城市道路面层抗滑性能抗滑指标:一般路段环境不良路段摆式仪测定值摆式仪测定值道路类别F 0（竣工）F （使用）构造深度m m石料磨光值F 0（竣工）F （使用）构造深度m m石料磨光值快速道路主干道>50K M /h 47-5037-400.4-0.6 37-40 52-55 42-45 0.3-0.5 42-45主干道<50K M /h 次干道≥45 ≥35 0.2-0.4 ≥35 ≥50 ≥40 0.2-0.4 ≥40Transportation College, Southeast University东南大学交通学院Pavement TypesThree types of PavementFlexible PavementRigid Pavement andComposite Pavement.Transportation College, Southeast University东南大学交通学院Pavement TypesBasic Flexible Pavement StructureTransportation College, Southeast University 东南大学交通学院Pavement TypesFlexible Pavement(1)Constructed of bituminous and granular materials,(2)Analyzed by Burmister’s layered theory, and (3)Surfaced with bituminous (or asphalt) materials.Transportation College, Southeast University 东南大学交通学院Pavement TypesFlexible PavementThree types of pavement have been used for flexible pavement:conventional flexible pavement,full-depth asphalt pavement andcontained rock asphalt mat(CRAM) pavement.Transportation College, Southeast University东南大学交通学院Pavement TypesConventional flexible pavement(1)Better materials on top where the intensity of stress is high, and(2)Inferior materials at the bottom where the intensity is low.Typical cross sectionTransportation College, Southeast University东南大学交通学院Pavement TypesFull-depth asphalt pavement (1)HMA directly on the subgrade,(2)Conceived by Asphalt Institute in 1960, and (3)The most cost-effective asphalt pavement for heavy traffic.Transportation College, Southeast University 东南大学交通学院Pavement TypesContained rock asphalt mats(CRAM)Transportation College, Southeast University 东南大学交通学院Pavement TypesAASHTO 2002Transportation College, Southeast University 东南大学交通学院Pavement Types磨耗层2.5cm,OGFC,改性沥青7.5cm排水沥青混凝土，油石比4.7％15cm沥青混凝土，沥青PG64-16，油石比4.7％抗疲劳层7.5cm沥青混凝土，油石比5.2％ESALs为200,000,00030I－710磨耗层5cmSMA3.75cm，最大公称粒径25mm，沥青PG70-2230cm，最大公称粒径37.5mm沥青稳定碎石15cm级配碎石预计2020年平均日交通辆236,000辆；ESALs为76,000,00030I－695磨耗层7.5cmSMA19，沥青PG76-22联结层7.5cm，最大公称粒径19mm，沥青PG76-2220cm最大公称粒径19mm，沥青PG70-22抗疲劳层5cm，Superpave12.5，沥青PG64-2220cm石灰稳定土2001年平均日交通量12,400辆,卡车占36％；预计2021年平均日交通量23,100辆—I－35磨耗层5cmOGFC，最大公称粒径19mm，沥青PG70-2825cmSuperpave19，沥青PG70-22碎石化混凝土—40I-5路面结构交通量设计年限道路名称Transportation College, Southeast University 东南大学交通学院Pavement TypesI-90 Flexible Pavement Performance Summary (from Mahoney, 2001)LocationTime SinceOriginalConstruction Original HMAThicknessTime fromOriginal Constructionto First ResurfacingAge or Current Wearing CourseCurrent IRICurrent RutDepthWestern WashingtonWeighted Average 25.8 years368 mm (14.5 in.)18.5 years7.4 years1.0 m/km (63 in./mi.)5 mm (0.20 in.)Number of Sections9 99 999Range23 - 29 years350 - 472mm (13.8 - 18.6in.)17 - 22 years 4 - 12 years0.7 - 1.3 m/km (44 - 82 in./mi.)2 - 7 mm (0.08 - 0.28in.)Transportation College, Southeast University 东南大学交通学院Pavement TypesI-90 Flexible Pavement Performance Summary (from Mahoney, 2001)LocationTime SinceOriginalConstruction Original HMAThicknessTime fromOriginal Constructionto First ResurfacingAge or Current Wearing CourseCurrent IRICurrent RutDepthEastern WashingtonWeighted Average 29.3 years240 mm (9.5 in.) 12.4 years4.7 years0.8 m/km (51 in./mi.)5 mm (0.20 in.) Number of Sections27 2725 252525Range6 - 35 years150 - 350mm (6.0 - 13.9in.)6 - 21 years2 - 10 years0.6 - 1.2 m/km (38 - 76 in./mi.)1 - 9 mm (0.04 - 0.35in.)Transportation College, Southeast University 东南大学交通学院Transportation College, Southeast University东南大学交通学院Pavement Types-Rigid pavementsRigid pavements are surfaced with Portland cement concrete (PCC).The concrete slab supplies the most of a rigid pavement's structural capacity.Transportation College, Southeast University东南大学交通学院Pavement Types-Rigid pavementsBasic Rigid Pavement StructureTransportation College, Southeast University东南大学交通学院Pavement Types-Rigid pavementsSurface course .This is the top layer, which consists of the PCC slab.Base course .This is the layer directly below the PCC layer and generally consists of aggregate or stabilized subgrade.Subbase course .This is the layer (or layers) under the base layer.A subbase is not always needed andtherefore may often be omitted.Transportation College, Southeast University东南大学交通学院Pavement Types水泥混凝土路面类型Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsRigid Pavement Types:Jointed plain concrete pavement (JPCP).The most common type of rigid pavement.JPCP controls cracks divided slabs by contraction joints.Slabs are typically one lane wide and between 3.7 m (12 ft.) and 6.1 m (20 ft.) long.Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsTransportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsCrack Control:Contraction joints, both transverse and longitudinalJoint Spacing:Typically between 3.7 m (12 ft.) and 6.1 m (20 ft.). Due to the nature ofconcrete, slabs longer than about 6.1 m (20 ft.) will usually crack in the middle. Depending upon environment and materials slabs shorter than this may also crack in the middle.ReinforcingSteel:None.Load Transfer:Aggregate interlock and dowel bars . For low-volume roads aggregateinterlock is often adequate. However , high-volume roads generallyrequire dowel bars in each transverse joint to prevent excessive faulting .Other Info:A majority of U.S. State DOTs build JPCP because of its simplicity and proven performance.Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsJointed reinforced concrete pavement (JRCP).These slabs are much longer (as long as 15 m (50 ft.)) than JPCP slabs,JRCP uses reinforcing steel within each slab to control within-slab cracking.Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavements Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsCrack Control:Contraction joints as well as reinforcing steel . Joint Spacing:Longer than JPCP and up to a maximum of about 15 m (50 ft.). Due to the nature of concrete, the longer slabs associated with JRCP will crack. ReinforcingSteel:A minimal amount is included mid-slab to hold cracks tightly together . This can be in the form of deformed reinforcing bars or a thick wire mesh.Load Transfer:Dowel bars and reinforcing steel .Dowel bars assist in load transfer across transverse joints while reinforcing steel assists in load transferacross mid-panel cracks.Other Info:During construction of the interstate system, most agencies in the Eastern and Midwestern U.S. built JRCP . Today only a handful of agenciesemploy this design (ACPA, 2001).In general, JRCP has fallen out of favor because of inferior performance when compared to JPCP and CRCP.Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsContinuously reinforced concrete pavement (CRCP).Cracks typically appear ever 1.1 -2.4 m (3.5 -8 ft.) are held tightly together by the underlying reinforcing steel.Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsTransportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsCrack Control:Reinforcing steelJoint Spacing:Not applicable. No transverse contraction joints are used. ReinforcingSteel:Typically about 0.6 - 0.7 percent by cross-sectional area (ACPA, 2001).Load Transfer:Reinforcing steel , typically No. 5 or 6 bars, grade 60.Other Info:CRCP generally costs more than JPCP or JRCP initially due to increased quantities of steel. Further , it is generally less forgiving of constructionerrors and provides fewer and more difficult rehabilitation options. However , CRCP may demonstrate superior long-term performance and cost-effectiveness. Some agencies choose to use CRCP designs in their heavy urban traffic corridors (ACPA, 2001).Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsBasic Structural Elements :Joints:Contraction Joints , Expansion Joints Construction JointsTransportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsLoad Transfer:()100%×∆∆=la Efficiency leave slab deflectionapproach slab deflection ∆l =∆a =where:Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsTransportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsAggregate InterlockAggregate interlock forms between the fractured surfaces along the crack below the joint saw cut.Generally, aggregate interlock is ineffective in cracks wider than about 0.9 mm (0.035 inches) .Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsDowel Bars:Dowel bars are short steel bars .They increase load transfer efficiency.This reduces joint deflection and stress in the approach and leave slabs.Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsDowel bars are typically 32 to 38 mm (1.25 to 1.5 inches) in diameter, 460 mm (18 inches) long and spaced 305 mm (12 inches) apart.Stainless or epoxyDowel bars are usually inserted at mid-slab depth and coated with a bond-breaking substance.Transportation College, Southeast University 东南大学交通学院Pavement Types-Rigid pavementsTie BarsThey are not designed to act as load transfer devices. Tie bars are typically used at longitudinal joints.Typically, tie bars are about 12.5 mm (0.5 inches) in diameter and between 0.6 and 1.0 m (24 and 40 inches long).Transportation College, Southeast University 东南大学交通学院Pavement Types-Composite pavements .A composite pavement is composed of both HMA and PCC .The use of PCC as a bottom layer and HMA as a top layer results in an ideal pavement with the most desirable characteristics.Transportation College, Southeast University 东南大学交通学院Pavement Types-Composite pavements .Transportation College, Southeast University 东南大学交通学院Pavement Types-Composite pavements .Transportation College, Southeast University 东南大学交通学院Pavement Design MethodsMethods of flexible pavement can be classified in six categories:Empirical method;Mechanistic-empirical method Typical and optimum design methods.Transportation College, Southeast University 东南大学交通学院Pavement Design Methods Transportation College, Southeast University 东南大学交通学院Pavement Design MethodsTransportation College, Southeast University 东南大学交通学院Pavement Design FactorsCostsLife expectancyRiding qualityRoad noiseConstruction experienceTransportation College, Southeast University 东南大学交通学院Pavement Design Failure CriteriaFlexible Pavement:Fatigue Cracking RuttingThermal Cracking-low-temperature crackingthermal fatigue crackingTransportation College, Southeast University 东南大学交通学院Pavement Design Failure CriteriaRigid Pavement:Fatigue Cracking Pumping or ErosionOther Criteria-Faulting, spalling and joint deteriorationTransportation College, Southeast University 东南大学交通学院Highway and Airport PavementTransportation College, Southeast University 东南大学交通学院Highway and Airport Pavement Transportation College, Southeast University 东南大学交通学院Pavement Design SystemsTransportation College, Southeast University 东南大学交通学院Pavement Design SystemsTransportation College, Southeast University东南大学交通学院Questions And Problems1．柔性路面、刚性路面定义、结构特性，二者在设计理论与方法上有何主要差别？2．机场道面、道路路面各有什么特点。