4., 5., 6. week, asphalt institute [وضع...

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Prof. Dr. Eng Shafik JendiaProf. Dr. Eng Shafik Jendia

Asphalt InstituteAsphalt Institute

Lectures of Lectures of 44., ., 55., ., 66. Week. Week44. Week . Week 2828. . 09 09 -- 0404. . 10 10 . . 2013201355. Week . Week 0505. . 10 10 -- 1111. . 10 10 . . 20132013

66. Week . Week 1212. . 10 10 -- 1818. . 10 10 . . 2013 2013 (Adha holiday)(Adha holiday)77. Week . Week 1919. . 10 10 -- 2525. . 10 10 . . 20132013

Prof. DR.Prof. DR. Eng. Shafik JendiaEng. Shafik Jendia

Islamic University of GazaIslamic University of Gaza


Standard and RegulationStandard and Regulation

THICKNESS DESIGN THICKNESS DESIGN Asphalt PavementsAsphalt Pavementsfor Highways & Streetsfor Highways & Streets

MANUAL SERIES NO. (MS-1)FEBRUARY 1991

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Design ConsiderationsDesign ConsiderationsClassifications of Highways and Streets

Selection of Design Input Variables

Stage Construction

Economic comparisons


Classifications of Highways and Classifications of Highways and StreetsStreets

Urban Functional Urban Functional SystemsSystems

Rural Functional Rural Functional SystemsSystems

Principals Arterial SystemPrincipals Arterial SystemInterstateInterstateOther freeways & expresswaysOther freeways & expresswaysOther principal arterialsOther principal arterials

Principals Arterial SystemPrincipals Arterial SystemInterstate Interstate (free ways)Other principal arterialsOther principal arterials

Minor Arterial Street SystemMinor Arterial Street SystemMinor Arterial SystemMinor Arterial System

Collector Street SystemCollector Street SystemCollector SystemCollector SystemMajor collectorMajor collectorMinor collectorMinor collector

Local Street SystemLocal Street SystemLocal SystemLocal System

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Rural Functional SystemsRural Functional Systems


Urban Functional SystemsUrban Functional Systems

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Relationship Between Road Systems And Relationship Between Road Systems And Their FunctionsTheir Functions


Compare between the American and European classification systems of

highways and streets

Classifications of Highways and StreetsClassifications of Highways and StreetsHome work

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Selection of Design Input Selection of Design Input VariablesVariables

All variables used in design should be based All variables used in design should be based on Studies of actual data.on Studies of actual data.

The Design Variables are:The Design Variables are:Subgrade PropertiesMaterial PropertiesTraffic ValuesEnvironmental Factors


Design PrinciplesDesign PrinciplesBasis for DesignBasis for Design

Design CriteriaDesign Criteria

Material CharacteristicsMaterial Characteristics

Environmental ConsiderationsEnvironmental Considerations

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BasisBasis for Designfor Design

The Pavement is regarded as a multiThe Pavement is regarded as a multi--layered elastic system.layered elastic system.The material in each of the layers are The material in each of the layers are characterized by a modulus of elasticity characterized by a modulus of elasticity and a Poisson’s ratio.and a Poisson’s ratio.Traffic is expressed in terms of repetitions Traffic is expressed in terms of repetitions of an equivalent of an equivalent 80 80 kNkN ((1818,,000 000 lb) lb) singlesingle--axle load.axle load.


The The subgradesubgrade, the , the lowest layer, is lowest layer, is assumed infinite assumed infinite in the vertically in the vertically downward and downward and in the horizontal in the horizontal directions.directions.

… … Basis for DesignBasis for Design

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BoussinesqVertical and Horizontal Stresses


+−×=

322

3

)(1

zazPzσ

( ) ( )( )

++

+

×+−+×= 3

22

3

22

12212 za

zza

zPh

µµσ

( )hzv σστ −=21

Boussinesq Vertical and Horizontal Stresses

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Boussinesq Vertical and Horizontal Stresses


E-Modulus of Soil (MN/m2)

Soil

Def

lect

ion

(mm

)

semi infinite massm ,E

Daa

mass

m ,E

D

a a


EaPD ××

=5.1

BoussinesqRelationship

Contact Pressure (p),

Modulus of Soil or Subgrade (E)

andDeflection (D)

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Environmental ConsiderationsEnvironmental ConsiderationsSubgrade modulus variation for the conditions where

freeze-thaw occurs

Frozen Subgrade Modulus

Normal Subgrade Modulus

Thaw (Reduced) Subgrade Modulus




The other layers, of finite thickness, are The other layers, of finite thickness, are assumed infinite in extent in the horizontal assumed infinite in extent in the horizontal directions. directions. Full continuity (“full friction”) is assumed at the Full continuity (“full friction”) is assumed at the interfaces between each of the layers.interfaces between each of the layers.

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In the methodology adopted for this manual, In the methodology adopted for this manual, loads produce two strains which, are critical for loads produce two strains which, are critical for design purposes. design purposes.

They are:They are:-- the horizontal tensile strain on the underside of the horizontal tensile strain on the underside of

the lowest asphaltthe lowest asphalt--bound layer.bound layer.

-- the vertical compressive strain at the surface the vertical compressive strain at the surface of the of the subgradesubgrade..



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Material CharacteristicsMaterial CharacteristicsAll Material were characterized by a All Material were characterized by a modulus of elasticity and Poisson's ratio.modulus of elasticity and Poisson's ratio.

Modulus of ElasticityModulus of Elasticity= dynamic modulus for asphalt mixture.= resilient modulus for untreated granular or soil (subgrade) materials.The dynamic modulus of asphalt mixtures

is highly dependent upon pavement temperature.


… … Material CharacteristicsMaterial CharacteristicsUntreated Granular MaterialsUntreated Granular Materials

Resilient Modulus of untreated granular Resilient Modulus of untreated granular materials vary with stress conditions in the materials vary with stress conditions in the pavement.pavement.

Values used in developing the design Values used in developing the design charts given in the Appendix of the charts given in the Appendix of the manual vary from fewer than manual vary from fewer than 103 103 MPaMPa((15000 15000 psi) to more than psi) to more than 345 345 MPaMPa((5050,,000 000 psi) psi)

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Environmental ConsiderationsEnvironmental ConsiderationsMean Annual Air Temperature (MAAT)

Three sets of Three sets of environmental environmental conditions are conditions are selected to selected to represent the represent the range of range of conditions to conditions to which the which the manual should manual should apply.apply.

Frost Frost EffectsEffects

Mean Annual Air Mean Annual Air Temp.Temp.

yesyesLess than or equal Less than or equal

77oo C (C (4545oo F)F)

PossiblePossible= = 1515..5 5 oo CC

((6060oo F) F)

NoNoGreater than or Greater than or

equal equal 2424oo C (C (7575oo F)F)


Soil Stresses and deflectionSoil Stresses and deflectionHome work

1- Calculate the vertical and horizontal stresses

at depth 0.1a, 0.3a, 0.5a, a, 5a, 10a. Draw the curves, which show the relationship between

all stresses and the depth (z). Where wheel load = 40 kN

2- Calculate the deflection on the surface of soil (subgrade E 30 MN/m2) caused by a wheel load of 40 kN. Plot the relationship between deflection and E-Modulus of

different Soils (E = 10, 20, 40, 60, 100, 150, ... MN/m2).

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Traffic AnalysisTraffic Analysis

Traffic Volume EstimatesTraffic Volume Estimates(initial and future traffic volume, analysis period, classification and (initial and future traffic volume, analysis period, classification and number of trucks, design lane, design period, traffic growth, etc..)number of trucks, design lane, design period, traffic growth, etc..)

Estimating EEstimating ESSALAL

Determining Design EDetermining Design ESSALAL


Traffic AnalysisTraffic AnalysisTraffic Volume EstimatesTraffic Volume Estimates

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Traffic AnalysisTraffic Volume Estimates

Percentage of Percentage of Trucks in Trucks in

Design LaneDesign Lane

Number of Number of Traffic LanesTraffic Lanes

((Two Directions)Two Directions)5050

45 45 ((3535--4848)*)*40 40 ((3535--4848)*)*

2244

6 6 or moreor more

Percentage of Total Truck Traffic in Design Lane

* Probable range


Traffic AnalysisTraffic AnalysisTraffic Volume EstimatesTraffic Volume Estimates

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Traffic AnalysisTraffic AnalysisEstimating EALEstimating EAL



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Example of U.S. axle-load distribution (based on truck count and weight data for typical U.S. Interstate rural highways)

2065

184.7

231

757

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Traffic AnalysisTraffic AnalysisDetermining Design EALDetermining Design EAL

Example worksheet for traffic

Analysis

2000

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Traffic AnalysisTraffic AnalysisHome work

In the previous Table

1- How can you determine / calculate the number of vehicle per year.

2- Classify the road according to its average truck factor.


Material EvaluationMaterial EvaluationSubgrade SoilsSubgrade Soils

Improved SubgradeEvaluation MethodsSampling and TestingSelection of Design Subgrade Resilient ModulusSubgrade Compaction

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Improved Subgrade


An improved subgrade is any course or courses of improved material between the native subgrade soil and the pavement structure. It may be a treated in-

place material, or an imported material.

Evaluation Methods


A subgrade resilient modulus can be determined from a laboratory test in accordance with procedures described

in the Asphalt Institute's Soils Manual (MS-10).

The resilient modulus may be approximated from the CBR test values according to the relationship

Mr (MPa) = 10.3 CBR orMr (psi) = 1500 CBR.

The resilient modulus may be approximated from the Resistance R-value test results according to the relationship

Mr (MPa) = 8.0 + 3.8 (R-value) orMr (psi) = 1155 + 555 (R-value).

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Subgrade Soils Tests and Sample Sizes


Selection of Design Subgrade Resilient Modulus

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From the graph, determine the design subgrade Mr value for the different design EAL values.

Design Subgrade Mr. Mpa PSi

Design Percentile Value

EAL

100006960104

930064,175105

825056.987.5106



Untreated Aggregate Base and Subbase Quality Requirements

Material EvaluationMaterial Evaluation

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Material EvaluationMaterial Evaluation

Untreated Aggregate Base and Subbase Quality Requirements


Material Evaluation Home work

U- Tubes1- Sand Equivalent Test

2- Field Density Test

3- R-Value Test

4- Resilient Modulus Test

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Structural Design ProcedureStructural Design ProcedureDesign ProcedureDesign Procedure

Select or determine input data- traffic value, EAL,- subgrade resilient modulus, Mr,- surface and base types.Determine design thicknesses for the specific conditions described by the input data.Prepare stage construction design, if appropriate.Make an economic analysis of the various solutions arrived at the design problemSelect final design.


…..…..Structural Design ProcedureStructural Design Procedure

Design ProcedureDesign Procedure

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Minimum Thickness of Asphalt concrete


… … Material CharacteristicsMaterial CharacteristicsEmulsified Asphalt MixesEmulsified Asphalt Mixes

The emulsified asphalt mixes included in this The emulsified asphalt mixes included in this manual are characterized by three types, manual are characterized by three types, depending on the type of aggregate.depending on the type of aggregate.

They are:They are:-- Type I: made with processed, denseType I: made with processed, dense--graded graded

aggregates.aggregates.-- Type II: made with semi-processed, crusher-run,

pit-run or bank-run aggregates.-- Type III: made with sand or silty sands.

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Thickness Determination For Full-Depth Asphalt Concrete Pavements



Example 1

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Example 1



Thickness Determination For Emulsified Asphalt Base Pavements

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Example 2



Example 2

240 mm

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Minimum Thickness of Asphalt concrete



Example 2

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Thickness Determination For Pavements with Asphalt concrete Over Untreated Aggregate Base



Example 3

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…..…..Structural Design ProcedureStructural Design ProcedureExample 3

140 mm



100 mm

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Minimum Thickness of Asphalt concrete over Untreated Aggregate Base


Pavement Design Pavement Design Home work1- Design a pavement with full depth asphalt concrete

Subgrade Modulus: Mr. = 50 MPa (7140 PSI)MAAT = 7o C, 15,5o C and 24o C

ESAL = 5x106

Comparison is required

2- Design a pavement with emulsified asphalt base Subgrade Modulus: Mr. = 50 MPa (7140 PSI)

MAAT = 7o C, 15,5o C and 24o CESAL = 5x106


3- Design a pavement with untreated aggregate base Subgrade Modulus: Mr. = 50 MPa (7140 PSI)



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Thickness Determination For Pavements with Emulsified Asphalt Mixes Over Untreated Aggregate Base



Thickness Determination For Pavements with Emulsified Asphalt Mixes Over Untreated Aggregate Base

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Pavement Design Pavement Design Home work

1- Design a pavement with: - an asphalt concrete surface

- an emulsified asphalt base and - an untreated aggregate base

Given:Subgrade Modulus: Mr. = 50 MPa (7140 PSI)



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