路面设计原理-02
Pavement types in China
Selection of Hot Mix Asphalt (HMA) Pavement
东南大学交通学院 黄晓明 [email protected] Tel:8379 5184
Transportation College, Southeast University 东南大学交通学院
• China Asphalt Pavement with stabilized materials as base course; PCC.
Transportation College, Southeast University 东南大学交通学院
HMA Pavement Mix Type Selection
Purpose • Designers need to consider factors
HMA Pavement Mix Type Selection
Purpose
• Mix types are OGFC, SMA, LSAM, ATB, and • traffic, environment, subsurface pavement structure, existing pavement condition and preparation, and economics.
Transportation College, Southeast University 东南大学交通学院 Transportation College, Southeast University 东南大学交通学院
• Fine and coarse-graded dense mixes.
Pavement Layers
• The pavement layers • surface course, • intermediate or binder course, and • base course.
Transportation College, Southeast University 东南大学交通学院
Pavement Layers
Transportation College, Southeast University
东南大学交通学院
1
Pavement Layers
Pavement Layers
• Surface Layer
• the highest quality materials.
• Intermediate Layer
• Its purpose is to distribute traffic loads so that
• It provides characteristics such as friction, smoothness, noise control, rut and shoving
stresses transmitted to the pavement foundation will not result in permanent deformation of that
resistance, and drainage. layer.
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 Layers
Pavement Traffic
• Base Layer
• Its major function is to provide the principal support of the pavement structure. • It should contain durable aggregates, which would not be damaged by moisture or frost action.
Transportation College, Southeast University 东南大学交通学院
• Traffic
• Vehicle loads can be expressed by a number of 18-kip(80kN) equivalent single axle loads (ESAL). • Traffic is defined according to the 20 year ESAL levels.
Transportation College, Southeast University 东南大学交通学院
Pavement Traffic
Determining Appropriate Mix Types • Determining Appropriate Mix Types
• 1. Determine total thickness of HMA required. New Construction: Conduct a structural design in accordance with established procedures. Rehabilitation: Perform a pavement and structural design evaluation.
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
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Determining Appropriate Mix Types
• 2. Determine the types of mixtures appropriate for the surface course based on traffic and cost. • (a) Identify the general traffic category for your pavement. • (b) Second, determine what aggregate size to use for a mix. • (c) Third, consider appearance. • (d) Finally, consider traffic flow.
Transportation College, Southeast University 东南大学交通学院
Determining Appropriate Mix Types
Transportation College, Southeast University
东南大学交通学院
Determining Appropriate Mix Types
Determining Appropriate Mix Types
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
Determining Appropriate Mix Types
Kind of Asphalt Mixture
Porous Asphalt Mixture
Air Void about 20%
Dense Graded
Air Void: about 5%
Stone Mastic SMA
Air Void: about 3%
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
3
Characteristics of Porous Pavement
Target Values for Porous Asphalt Mixture
Items Percentage of Air Voids Permeable Coefficient (cm/s) Target Values About 20 Min. 10-2
Surface Pervious
Binder Course(Impervious
Impervious
Binder Course (Impervious
Min. 3.5kN as the Marshall stability is preferable. (5.0kN or more in Japan Highway Public Corporation) Min. 3000 pass/mm as Dynamic stability is set at the part where there are many heavy traffic. In the Execution Point for Paving stipulated in Japan Highway Public Corporation, about air voids of 17% and the Cantabro Loss of Max. 20% at -20 degrees C are set for the snowy and cold area. (the Cantabro loss of 20% at 20 degrees C for the ordinary area)
Transportation College, Southeast University 东南大学交通学院
Porous Pavement
Transportation College, Southeast University
Conventional Pavement
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Flow of Rainwater on Pavement
Porous Pavement
Setting of Drainage Pipes at the part with sharp longitudinal slope
Plane Figure Longitudinal Section
Porous Pavement
Longitudinal Slope
Permeation of Rainwater
(Pervious)
Conventional Pavement
Air Void 20% Flow of Rainwater Below Surface (Impervious)
Surface
Flow of Rainwater
Impervious binder course Crosscut Porous Pavement Drainage Pipe
(Impervious)
Cross slope
Surface
Below Surface (Impervious)
Impervious binder course
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
Effects of Porous Pavement
Permeable Effects
Improvement in Skid Resistance Prevention from Smoking and Splash Improvement in Visibility Restraint of Hydroplaning Restraint of Traffic Jam in Rainy Day Restraint of Urban Flood
Road Users Environmental Improvement
Relation Between Pavement Kind and Skid Resistant Coefficient
(Average 1992
0.6 （μ 0.5 0.4 0.3 0.2 0.1 0 Dense-Graded Dense/Gap Porous Cement Co.
东南大学交通学院
Noise Reduction Effects
Improvement in Roadside Environment Reduction in Driver’s Fatigue
1998)
Durable Effects
Rutting Resistance Cracking Resistance
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Roadside People
Drainage Function
Road Manager
东南大学交通学院
Transportation College, Southeast University
Skid Resistace (80)）
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Effects to Safety Driving
Change in Monthly Accident Rate
Accident Rate Number/100millions vehicles km
Porous Pavement in Rain
(Expressway)
300 250 200 150 100 50 0 -20 -10 0 10
Execution
20
30
40
50
60
70
80
Transportation College, Southeast University 东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
Porous Pavement in Rain (City Road)
Mechanism for Tire/Road Noise
Noise by Air-Pumping
Vibration Noise by Tire Pattern
Vibration Noise by Uneven Surface
Transportation College, Southeast University 东南大学交通学院 Transportation College, Southeast University
Vibration Noise by Skid Resistance
东南大学交通学院
Driving Velocity & Noise Level
100
Car, Tire/Road Surface Noise
Desired Properties as a Mixture or Asphalt
Desired Properties as Mixture Aggregate Strong Adhesion Scattering between Aggregates Resistance Weather Thick Asphalt Film on Aggregates Resistance Desired Properties as Asphalt
Use of Asphalt with Higher Toughness Use of High-Viscosity Modified Asphalt
Noise Level （ｄB(A)）
95 90 85 80 75 70 25 35 45 55 Driving Velocity （km/hr） 65 75 Porous + Surface Treatment Dense-Graded (13mm Top) Porous (Void 20%, 13mm Top）
Water Improvement in Use of Highly Cohesive Resistance Resistance to Stripping Asphalt Rutting Resistance
Higher Resistance to Rutting Higher Viscosity at 60 , Higher Softening Point
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
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Properties of High-Viscosity Asphalt
Test Items Penetration (25 degrees C, 1/10mm) Softening Point (degrees C) Ductility (15 degrees C, cm Flash Point (degrees C) Loss on TFOT (%) Residual Penetration Ratio After TFOT (%) Toughness (Nm) Tenacity (Nm) Viscosity at 60 degrees C (Pa s) Asphalt with TPS 46 92.5 91 322 0.06 82.5 23.8 16.1 250,000 Standard Properties Min 40 Min 80 Min 50 Min 260 Max 0.6 Min 65 Min 20 Min 15 Min 20,000
Asphalt properties
Chinese & Japanese)
China Japan Original Asphalt (Imported from Singapore Stand. (60/80) #70)
TPS Content (%) Pen. (1/10mm Softening P. Viscosity at 60 10000 Pa-s Toughness (N-m Tenacity N-m 10 40 81.7 21.3 30.1 25.1 12 40 82.0 38.5 21.3 17.3 52 47.9 14 35 87.4 74.3 27.9 20.0 16 38 88.3 84.9 23.2 18.3 12 44 88.6 18.2 26.0 18.7 63 46.3
东南大学交通学院
40 80 2.0 20 15
Note: Standard properties are due to the Technical Guideline for Porous Asphalt Pavement issued by Japan Road Association. Standard for viscosity at 60 C is Min. 40,000Pa s in Japan Highway Public Corporation. Mix Proportion of Asphalt with TPS is as follows; 60/80StAs TPS=88 12
Transportation College, Southeast University 东南大学交通学院
Original As. Pen. Original As. S.P.
Transportation College, Southeast University
New Evaluation Method for High-Viscosity Asphalt with High-Durability (Asphalt Bending Test)
Items Size of Specimen (mm) Span Length (mm) Loading Rate (mm/min) Loading Condition Curing Temperature Test Conditions 120 20 80 100 Loading at Center, Support at 2 points -20 degrees C 20
New Evaluation Method for High-Viscosity Asphalt with High-Durability (Asphalt Bending Test)
Test Temperature: -20 degrees C
Case of using conventional high-viscosity asphalt
东南大学交通学院
Case of using high-viscosity asphalt with high-durability
Transportation College, Southeast University 东南大学交通学院
Transportation College, Southeast University
Perpetual Bituminous Pavements
• 厚沥青路面的性能问题
lack of durability(stripping) in intermediate layer
Perpetual Bituminous Pavements
• 永久路面的基本要素 rut resistant－抗车辙 impermeable－不透水 wear resistant top structural－表层抗滑特性 • 各层要求 rut resistant and durable intermediate layer－ 中间层抗车辙和耐久 a fatigue resistant and durable base layer－ 基层抗疲劳和耐久
中面层的耐久性（剥落） thermal cracking 温度开裂 fatigue cracking 疲劳开裂
Transportation College, Southeast University 东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
6
Perpetual Bituminous Pavements
Perpetual Bituminous Pavements
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
Perpetual Bituminous Pavements
Perpetual Bituminous Pavements
应变标准
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
Perpetual Bituminous Pavements
I-90 Flexible Pavement Performance Summary (from Mahoney, 2001)
Time from Time Since Location Original Construction Original HMA Thickness Original Construction to First Resurfacing Age or Current Wearing Course Current IRI Current Rut Depth
Perpetual Bituminous Pavements
I-90 Flexible Pavement Performance Summary (from Mahoney, 2001)
Time from Time Since Location Original Construction Original HMA Thickness Original Construction to First Resurfacing Eastern Washington Age or Current Wearing Course Current IRI Current Rut Depth
Western Washington Weighted Average Number of Sections 368 mm (14.5 in.) 1.0 m/km (63 in./mi.) 5 mm (0.20 in.)
25.8 years
18.5 years
7.4 years
Weighted Average Number of Sections
29.3 years
240 mm (9.5 in.)
12.4 years
4.7 years
0.8 m/km (51 in./mi.)
5 mm (0.20 in.)
9
9
9
9
9
9
27
27
25
25
25
25
350 - 472 Range 23 - 29 years mm (13.8 - 18.6 in.) 17 - 22 years 4 - 12 years
0.7 - 1.3 m/km (44 - 82 in./mi.)
2 - 7 mm (0.08 - 0.28 in.)
150 - 350 Range 6 - 35 years mm (6.0 - 13.9 in.) 6 - 21 years 2 - 10 years
0.6 - 1.2 m/km (38 - 76 in./mi.)
1 - 9 mm (0.04 - 0.35 in.)
Transportation College, Southeast University
东南大学交通学院
Transportation College, Southeast University
东南大学交通学院
7
Questions And Problems
• 1．请解释沥青路面各层位的定义与作用。 • 2．请解释沥青混合料的类型与特点。 • 3．什么是永久性路面？请根据国内外的实际 提出永久性路面的基本要求与结构组合。 • 4．排水性路面的特点与要求，请说明排水性 面层与排水性基层的原材料要求与混合料组成 设计的基本要求。
Transportation College, Southeast University 东南大学交通学院
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