e_div-12-superior performance asphalt pavement

8/12/2019 E_div-12-Superior Performance Asphalt Pavement

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DIVISION 12 SUPERIOR PERFORMANCE ASPHALT PAVEMENT 325

12.1 Preface 325

12.2 Description 328

12.3 Materials 32812.3.1 Asphalt Materials 328

12.3.2 Aggregate 330

12.3.2.1 Quality Requirements For Combined Aggregate 331

12.3.2.2 Gradation Of Total Aggregate 332

12.4 Mix Design 335

12.4.1 Job-Mix Formula Requirements 336

12.4.2 The Design Job-Mix Formula 336

12.4.3 Procedures For Acceptance Of Job-Mix Formula 337

12.5 Construction 337

12.6 Traffic Control 338

12.7 Works Acceptance 338

12.7.1 Quality Control 339

12.7.2 Quality Assurance 339

12.8 Measurement and Payment 341

EXIT


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General Specifications of Urban Roads Construction Division 12-Superior performance asphalt pavement

Ministry of Municipal & Rural Affairs - Kingdom of Saudi Arabia 325

DIVISION 12

SUPERIOR PERFORMANCE ASPHALT PAVEMENT

12.1 Preface:

Design of Superior Performance Asphalt Pavements (Superpave) has been

developed on the basis of intensive research conducted to limit failures and distresses in

asphalt pavements during different stages of their service life. Superpave (which will be

defined later in this specification as the superior performance pavements) is an

abbreviation to SUperior PERformance Asphalt PAVEment.

Superpave system consists of requirements and specified methods for selection

of asphalt binder and aggregates which shall be met in the design and construction of

superior performance pavement layers. The Superpave system also consists of the

asphalt mix design method in three levels; the first level is defined as the volumetricdesign in addition to tests for determination of performance in the second and third

levels which are still in the development phase.

The Superpave specifications depend on the environmental factors, layer

location from pavement surface and actual traffic volume on the road.

The physical characteristics of the asphalt binder, which directly affect its performance

in the road, are measured by a series of specified tests at temperatures which simulate

the maximum and minimum temperatures to which the asphalt binder is subjected to

during mixing, spreading, compaction and service (pavement service life). Table

(12.2.1) shows these tests which are used to determine the type of the asphalt binder on

the basis of performance grade (PG). The identification consists of suffix numbers to

these two letters (PG) indicating the maximum and minimum temperatures within

which the asphalt binder is expected to perform satisfactorily. For example the grade

PG76-10 is expected to resist rutting at maximum temperature of seventy six (76)

degree Celsius and resist thermal cracking at minimum temperature of minus ten (-10)

degree Celsius.

The real difference between the specifications of Superpave and the traditional

specifications (penetration and viscosity) is in the performing of tests at different

temperatures, which suit the operational conditions of the project, in order to obtain the

target value in the specifications instead of fixing the test temperature and changing thatvalue.

Tests on asphalt binder or on asphalt mix are performed at temperatures

simulating those to which the asphalt mix is subjected during the pavement service life

and the behavior or performance of the asphalt binder depends on the temperatures and

the prolonging or shortening of the traffic loading period.

The Superpave combined these two factors loading period and temperature- by their

mutual effect on the asphalt binder and the asphalt mix where the slow loading rate is

simulated by the high temperatures and the quick loading rate by the low temperatures.

The specifications of the Superpave require obtaining records of temperatures inthe project area for twenty (20) years for determination of the adequate performance

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grade, where the minimum daily temperature and the maximum seven days average

temperature shall be determined during the approved monitoring period in the General

and/or Special Specifications.

Table 12.2.1: Asphalt Binder Tests

No. Test Aim

1Rolling Thin Film Oven Test

(RTFO)

Simulation of short term aging of asphalt

binder (< two years)

2 Pressurized Aging Vessel (PAV)Simulation of long term aging of asphalt

binder (>seven years)

3 Dynamic Shear Rheometer (DSR)

Measurement of asphalt binder

characteristics at intermediate and higher

temperatures

4 Rotational Viscosity (RV) Measurement of asphalt bindercharacteristics at higher temperatures

5 Bending Beam Rheometer (BBR)

6 Direct Tension Tester (DTT)

Measurement of asphalt binder

characteristics at lower temperatures

The adequate performance grade or type of the asphalt binder for the project

area is determined according to the following steps:

1- Determination of the minimum pavement temperature using the minimum airtemperature in the monitored period or by applying the following formula:

Low, Tpav= - 1.56+0.72Tair 0.004Lat2+6.26 Log10(H+25) - Z (4.4+0.52air

2)0.5

Where;

Tpav= Minimum pavement design temperature, C at H mm depth from the

surface.

(minimum expected pavement temperature degree during the design

period.Tair = Minimum daily air temperature, C

Lat = Geographical location of the project (latitude) in degrees.Z = Reliability factor = 2.055 at reliability 98 %

H = depth to the surface.

air = standard diviation of minimum airdaily temperature.

2- Determination of the maximum pavement temperature as the temperature at adepth of twenty (20) millimeters from the pavement surface, which is

determined from approved mathematical formulas by using the average air

temperature for the hottest seven days during the monitoring period and the

geographical location of the project (latitude), using the following equation :

High, Tpav =54.32+0.78Tair0.0025Lat2

-15.14 Log10(H+25)+Z (9+0.61air2

)0.5

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Where;

Tpav= Maximum pavement design temperature at H mm depth from pavement

surface, C.

Tair = Average hottest seven days air temperature, C.

Lat = Geographical location of the project (latitude) in degrees.

Z = Reliability factor = 2.055 at reliability 98 %H = depth to the surface.

air = standard deviation of maximum seven day airtemperature.

3- The reliability used in determination of the maximum or minimum temperatureshall not be less than ninety eight (98) percent. This implies increasing the

average maximum temperatures and decreasing the average minimum

temperatures by twice the standard deviation value of the average temperatures

for twenty years period.

The aggregate plays an important role in the performance of asphalt mixes at

high temperatures and high humidity. This role is less important at low temperatures infatigue cracking and low thermal cracking problems. The characteristics of aggregates

are classified in the Superpave specifications into three groups as follows:

1- Consensus Properties: Consensus properties are used for determination of theangularity of the fine and coarse aggregate grains and the degree of fracture and

number of fractured faces and are considered as one of the important factors in

obtaining the required performance of the asphalt mix. Specific requirements in

these properties shall be satisfied on the basis of traffic volume and location of

the layer from pavement surface. These properties are :

- Coarse Aggregate Angularity- Fine Aggregate Angularity- Flat and Elongated Particles- Clay content

2- Source Properties: Source properties are used in judgment of suitability of thesource of aggregates used in production of the Superpave, for its importance in

quality assurance. These properties include the following:

- Toughness- Soundness-

Deleterious Materials

3- Gradation Properties: Superpave has developed methodology for determinationof aggregate gradation in asphalt mixes by considering the gradation curve of

sieve sizes raised to the power 0.45. This curve consists of a straight line joining

the point of the 100% passing at the maximum size and the zero point, called the

maximum density line. Two additional properties have been added to the

maximum density line, which are :

- Control Points.- Restricted Zone.

Control points are upper and lower limits for the percentage passing fromdefinite sieves. These Sieves are the maximum size, the maximum nominal size, the

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intermediate size 2.36 mm and the minimum size 0.075 mm. The control point value in

each sieve differs by the variation of the maximum nominal size of the aggregate. The

restricted zone is a zone where the gradation curve is not recommended to pass through,

since the gradation passing through this zone will have insufficient voids in the mineral

aggregate (VMA) and is considered to be highly sensitive to any increase or decrease in

asphalt content.

The aggregate gradation selected for Superpave is known as the Design

Aggregate Structure and should preferably pass below the restricted zone.

The performance of the asphalt mixes is determined from series of tests on

prepared laboratory specimens using gyratory compactor and by measurements of the

volumetric properties which include air voids, voids in the mineral aggregate and voids

filled with asphalt and then use these properties and measurements in performance

models for estimation of the number and shape of pavement distresses on the basis of

time and traffic factors.

12.2 Description:

This section includes provision of the asphalt binder which satisfies the required

performance specifications for the project area and selection of the suitable aggregate in

terms of gradation and quality requirements for production of an asphalt mix which

satisfies the performance requirements and design conditions stated in the this General

or Special Specifications and hauling , spreading and compacting the mix for

construction of the superior performance asphalt pavement layers in accordance with

the plans , Special Specifications , contract documents and this General Specifications .

12.3 Materials:

12.3.1 Asphalt Materials:

The asphalt materials used in the Superpave consist of the modified or unmodified

asphalt binder which shall satisfy the quality requirements shown in Table (12.3.1) of

this general Specification. Unless otherwise defined in the contract documents or in

the Special Specifications, the contractor shall submit a study, prepared by a specialized

authority, which shows the suitable performance grade of the asphalt binder for the

project area.

The performance grade shall be determined according to the sequence followed in

the standard AASHTO PP-6 The Standard Method of Approving the Suppliers Gradeof the Asphalt Binder and Specifications of Performance grade of the Asphalt Binder

AASHTO MP-1 standard.

The performance grade of the asphalt binder shall be selected on the basis of

temperatures of the project location in any zone in the Kingdom, using the equations in

item 12.1 of this division and in case there is no information about the project the

performance grade shown in Figure (12.3.1) Temperature Zones of the Kingdom shall

be use. This selected grade shall be increased by the performance degrees shown in

Table (12.3.2), according to the speed and the design traffic volume in ESALs in the

design lane for twenty (20) years. The properties of the selected asphalt binder shall

conform to the requirements shown in Table (12.3.1).

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When the available asphalt binder does not satisfy the performance

requirements, the Contractor shall modify the asphalt binder by using one of the

approved and common modifiers (Polymers) in the Kingdom. He shall also submit

technical report, prepared by specialized authority, showing the proposed polymer type,

its percentage, method of addition and test results which verify the satisfaction of the

asphalt binder type to the quality requirements shown in Table (12.3.1).

Table 12.3.1: Quality Requirements of Performance Grades of Asphalt Binder

Test Description Specification Requirements

New Asphalt

Flash point AASHTO T-248 2300C (min)

Rotational Viscosity At 1350C

AASHTO

TP-483 Pa.sec (max)

Dynamic Shear (DSR)G*/sinat 10 rad /sec

At the highertemperature

AASHTOTP-5

1 kPa (min)

Specimens of Asphalt Residue from RTFO

% loss (RTFO) At 1630C

AASHTO T-

2401% (max)

Dynamic Shear (DSR),

G*/sin

At the higher

temperature

AASHTO

TP-52.2 kPa (min)

Specimens of Asphalt Residue from RTFO and PAV

Dynamic Shear (DSR),

G*sin

At the median

temperature *

AASHTO

TP-5

5000 kPa

(max)

CreepStiffness (S)

At minimumtemperature +10

C for 60 sec

AASHTOTP-1

300 Mpa (max)Bending

Beam

Rheometerm-value

At minimum

temperature +10

C for 60 sec

AASHTO

TP-10.3 (min)

Direct Tension At minimum

temperature

AASHTO

TP-31% (min)

*NOTE: see Table 1 in Appendix 2.

Table 12.3.2: Increase of Performance Degree of Asphalt Binder on the Basis of

Traffic Volume and Speed

Increase of Performance Degree According to Traffic SpeedDesign Traffic

Volume

(million ESALs)70 kph

< 0.3 No need

0.3 -


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Figure 12.3.1: Temperature Zones of the Kingdom

The selected performance grade shall be modified on the basis of climate

temperature in the project area in accordance with Section 12.2 or as determined from

Figure (12.3.1), by increasing the maximum temperature only by the amount of the

performance degrees shown in Table (12.3.2) (each performance degree equals six (6)

degrees Celsius), according to the speed and design volume of traffic on the road. The

minimum temperature in the performance grade shall not be modified. For example, ifthe selected performance grade for a project, according to the pavement temperature, is

PG70-10 and the design traffic speed is greater than seventy (70) kph and the design

traffic volume is between ten (10) to thirty (30) million ESAL in the design lane, the

performance grade of the asphalt binder shall be increased one degree to be of the type

PG76-10.

The Contractor shall use modified asphalt binder in construction of Superpave

asphalt concrete according to the ministry request in any of the Kingdom zones and

taking into consideration that the performance degree of that asphalt binder is increased

according to traffic volume and speed in the target project as shown in figure (12.3.1)and Table (12.3.2). The contractor has the right to request about the modification cost if

it is not mentioned in the contract documents, but if the ministry does not request that

and it is not mentioned in the contract documents the Contractor has no right to claim

any additional compensation accordingly.

12.3.2 Aggregate:

The aggregate used in production of Superpave shall meet all stated

requirements in this section of the General Specification, unless otherwise stated in the

Special Specifications. The Contractor shall, at his own responsibility, define the

source(s) and the aggregate quantities suitable for work in accordance with the

requirements of this General Specifications or the Special Specifications.

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The different aggregate sizes shall be stockpiled on stable clean leveled surface

and in spaced heaps of not less than ten (10) meters apart or in wall-separated heaps.

The aggregates shall be hauled from stockpiles locations by equipments which are

approved by the Engineer. The hauling and/or stockpiling method shall not lead to

pollution of the environment or aggregate or particle segregation.

The Contractor is allowed to use up to 15% by weight of total aggregates of non

fractured fine aggregate for production of Superpave, provided that the total mix of the

fractured and non fractured fine aggregate shall conform to the fine aggregate angularity

which is based on the uncompacted air voids of this General Specifications or the

Special Specifications.

The mineral filler used in Superpave shall be a product of rock powder or rock

dust with plasticity index not more than 4%. It may also be of furnace slag and/or metal

raw or Portland cement or hydrated lime or any other material which will satisfy the

quality requirements as in AASHTO M-85 or AASHTO M-240 for Portland cement and

ASTM C 207 for hydrated lime.

12.3.2.1 Quality Requirements for combined Aggregate:

The combined aggregate shall satisfy all consensus properties shown in Table

(12.3.3), and the flat and elongated particles test shall be performed on materials

retained on sieve 4.75 mm while the percent of air voids test on the uncompacted fine

aggregate shall be performed on materials passing sieve 2.36 mm, according to the

method defined in the above mentioned Table.

Not contradicting the Special Specifications, the source properties of the

aggregate used in Superpave production, shall conform to all requirements listed in

Table (12.3.4), according to the defined test method.

All tests listed in Tables (12.3.3) and (12.3.4) of this General Specifications

shall be performed on the blended aggregate which is selected for production of

Superpave concrete, except the Los Angeles Abrasion Test which may be performed on

the blended aggregate or for each source / stockpile alone.

Table 12.3.3: Aggregate Consensus Properties Requirements

Coarse Aggregate

Angularity

(At least %)

Percent of Air Voids in

fine Aggregate (passing

4.75 mm sieve)

(At least %)

Layer Location from Pavement Surface*

Design

TrafficVolume

(ESAL)

(million)


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Table 12.3.4: Requirements of the Aggregate Source Properties

Aggregate Properties Test Method Requirements %

Los Angeles Abrasion

(max)AASHTO T-96 40

Soundness (loss in SodiumSulphate) (max)

AASHTO T-104 20

Clay lumps and friable

particles (max)AASHTO T-112 0.25

12.3.2.2 Gradation of Total Aggregate:

The combined aggregate of Superpave shall satisfy one of the gradation

requirements shown in Tables from (12.3.5) to (12.3.9) which is classified according to

the nominal maximum size of the aggregate.

The percent of aggregate used in the asphalt mix shall be determined by the useof the average gradation results of five representative and independent samples taken

from each stockpile and/or cold bins and/or hot bins, and at least three trials shall be

performed for different gradations within the specification limits of the approved

gradation for each Superpave mix in order to determine the design aggregate structure

and the percentages of the different aggregate sizes.

Satisfaction of the aggregate sizes to quality and gradation requirements shall be

checked whenever the source and /or method of fracture change. The maximum

nominal size shall not be greater than half the pavement layer thickness.

Table 12.3.5: Gradation of combined Aggregate

(Maximum Nominal Size is 9.5 mm)

Control Points (%) Restricted Zone (%)Sieve

Size

(mm)Minimum Maximum Minimum Maximum

Target

Design

Values*(%)

Tolerance

Limits (%)

12.50 100 - - - - -

9.50 90 100 - - - -

4.75 - 90 - - * 6

2.36 32 67 47.2 47.2 * 6

1.18 - - 31.6 37.6 - -

0.600 - - 23.5 27.5 * 4

0.300 - - 18.7 18.7 * 3

0.150 - - - - - -

0.075 2 10 - - * 2

* represents target values which the Contractor shall determine during the asphalt mix design to thenearest

0.1% , and tolerance limits shown are the permissible deviation from target values.

** It is better if the total gradation avoid the restricted zone and that according to the engineer acceptance.

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(Maximum Nominal Size is 12.5 mm)

Control Points (%) Restricted Zone (%)Sieve Size

(mm) Minimum Maximum Minimum Maximum

TargetDesign

Values*(%)

Tolerance

Limits (%)

19 100 - - - -

12.50 90 100 - - - -

9.50 90 - - - -

4.75 - - * 6

2.36 28 58 39.1 39.1 * 6

1.18 - - 25.6 31.6 - -

0.600 - - 19.1 23.1 * 4

0.300 - - 15.1 15.1 * 3

0.150 - - - - - -0.075 2 10 - - * 2


0.1% , and tolerance limits shown are the permissible deviation from target values.** It is better if the total gradation avoid the restricted zone and that according to the engineer acceptance.

Table 12.3.7: Gradation of combined Aggregate(Maximum Nominal Size is 19 mm)


Size

(mm)Minimum Maximum Minimum Maximum

Target

Design

Values*(%)

Tolerance

Limits (%)

25 100 - - - - -

19 90 100 - - - -

12.50 - 90 - - - -

9.50 - - - - - -

4.75 - - - - * 6

2.36 23 49 34.6 34.6 * 61.18 - - 22.3 28.3 * -

0.600 - - 16.7 20.7 * 4

0.300 - - 13.7 13.7 * 3

0.150 - - - - - -

0.075 2 8 - - * 2

* represents target values which the Contractor shall determine during the asphalt mix design to the

nearest0.1% , and tolerance limits shown are the permissible deviation from target values.


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(Maximum Nominal Size is 25 mm)


Size(mm)

Minimum Maximum Minimum Maximum

Target

DesignValues*(%)

Tolerance

Limits (%)

37.5 100 - - - - -

25 90 100 - - - -

19 - 90 - - - -

12.50 - - - - - -

9.50 - - - - - -

4.75 - - 39.5 39.5 * 6

2.36 19 45 26.8 30.8 * 6

1.18 - - 18.1 24.1 * -

0.600 - - 13.6 17.6 * 4

0.300 - - 11.4 11.4 * 3

0.150 - - - - - -

0.075 1 7 - - * 2

* represents target values which the Contractor shall determine during the asphalt mix design to the

nearest0.1% , and tolerance limits shown are the permissible deviation from target values.


Table 12.3.9: Gradation of combined Aggregate(Maximum Nominal Size is 37.5 mm)

Control Points (%) Restricted Zone (%)Sieve Size

(mm) Minimum Maximum Minimum Maximum

Target

Design

Values*(%)

Tolerance

Limits (%)

50 100 - - - - -

37.5 90 100 - - - -

25 - 90 - - - -

19 - - - - - -

12.50 - - - - - -

9.50 - - - - - -

4.75 - - 34.7 34.7 * 6

2.36 15 41 23.7 27.3 * 6

1.18 - - 15.5 21.5 *

0.600 - - 11.7 15.7 * 4

0.300 - - 10 10 * 3

0.150 - - - - - -

0.075 0 6 - - * 2


0.1% , and tolerance limits shown are the permissible deviation from target values.


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12.4 Mix Design:

Design of superior performance asphalt mix shall be in accordance with the

Asphalt Institute method shown in Superpave Series No. 2 (SP-2) Mix Design of

Superpave Asphalt concrete. The Appendix (2) of this General Specifications shows an

example of Superpave volumetric mix design method.

The design steps of the asphalt mix, as in level one of the superior performanceasphalt pavement mix Design by the Volumetric Method, include the following:

1- Selection of the asphalt binder which satisfies the approved requirements as initem 12.3.1 of this Specification.

2- Selection of the aggregate which satisfies the specifications of the definedsource and consensus properties and meets the required gradation according to

the maximum nominal size by performing three different trail blends and

comparing them with the combined gradation requirements.

3- Estimation of the preliminary optimum asphalt binder content for each blend.4- Determination of the temperature range for each of the mixing and compaction

by performing the Rotational Viscosity test as in AASHTO TP-48 such that the

suitable mixing viscosity of the asphalt binder will in the range of (0.17 0.02)and for compaction will be in the range (0.28 0.03) Pa.sec .

5- Selection of the optimum asphalt binder content as follows:- Mixing asphalt with the different aggregate blends and heating (aging)

the mix in the oven at compaction temperature specified by rotational

viscosity test for two hours if the aggregate absorption does not exceed

2% and for four hours if the absorption exceeding this value, then

compacting the specimens by the gyratory compactor as in AASHTO

TP-4 method, The Standard Method for Preparation and Determination

of the Specific Gravity of Compacted Specimens by the Gyratory

Compactor.

- Analysis of the volumetric properties of the compacted mix andcomparing them with the volumetric properties as in Superpave system

and selection of the best results as design aggregate structure according

to the specification AASHTO PP-19 The Standard Volumetric Analysis

Method for Compacted Hot Mix.

- Compaction of specimens from the design aggregate gradation withdifferent asphalt contents, plotting the asphalt binder versus the air voids

in the compacted specimens curve and determination of the design

asphalt binder content at four (4) percent air voids.

- Determination of the volumetric properties using the optimum asphaltcontent from the plotted curves of; asphalt binder content versus thevolumetric properties of the asphalt mix (Voids in the Mineral

Aggregate (VMA), Voids Filled with Asphalt (VFA), density at initial

(Nini), design (Ndes) and maximum (Nmax) compaction levels and then

comparison with the requirements of the volumetric properties shown in

Table (12.4.2).

6- Evaluation of the resistance of the selected asphalt mix to water effect

according to AASHTO T-283 method.

Table (12.4.1) shall be considered as guidelines for the selection of the required

compaction level in the laboratory for the asphalt mix on the basis of the design traffic

volume in EASLs in the design lane for twenty (20) years.

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Table 12.4.1: Superpave Compaction levels

No of gyrations

Maximum Design Initial

Design

ESAL

(million) Nmax Ndes Nini

Road Class

< 0.3 75 50 6 Residential0.3 - < 3 115 75 7 Collector

3 - < 30 160 100 8Expressway Arterial / Industrial

Regions

30 205 125 9Expressway / Truck Parking /

Decent Lanes / Intersections

12.4.1 Job-Mix Formula Requirements:

The asphalt binder shall satisfy the quality requirements shown in Table

(12.3.1), and the Contractor shall define and verify the target values of the gradation of

the total aggregate of the Superpave within the allowed limits shown in Table (12.3.5)

or Table (12.3.6) or Table (12.3.7) or Table (12.3.8) Table or (12.3.9) according to the

nominal maximum size of the aggregate provided that the quality requirements shown

in Tables (12.3.3) and (12.3.4) shall be satisfied. The asphalt mix shall also satisfy the

volumetric properties shown in Table (12.4.2).

The ratio of the average tensile resistance of the compacted specimens subjected

to environmental conditioning to average tensile resistance of the compacted specimens

not subjected to environmental conditioning shall not be less than seventy five (75)

percent as determined by AASHTO T-283 test Resistance of the compacted

bituminous Mixture to moisture induced Damages.

Table 12.4.2: Requirements of the Volumetric Properties of Superpave

Voids in the Mineral

Aggregate (VMA)

(at least %)

Ratio of Required

Density to Maximum

Theoretical Density

(%Gmm) Nominal Maximum Size

(mm)

ESALs

(million)

Nmax Ndes Nini 9.5 12.5 19 25 37.5

Voids

Filled

with

Asphalt

(VFA)

**

Ratio of

Percentage

Passing Sieve

0.075 mm to

Asphalt

Binder

Content *


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of materials used in the asphalt mix production, material proportions, original test

results of consensus properties, source properties required for aggregate materials which

proves conformity with the specified requirements and the original test results of the

designed asphalt mix in the laboratory which shall include; gradation, specific gravity

for aggregate sizes, test results of the asphalt binder, grade, type and percentages of

used modifiers, mixing method, plant location and test results of plant production.

12.4.3 Procedures for Acceptance of Job-Mix Formula:

The job-mix formula furnished by the Contractor shall be revised by the

ministry and shall be accepted or retuned to the Contractor for modifications within two

weeks. The Contractor shall prepare once again and resubmit to the ministry, for

approval, a new job-mix formula which will satisfy the specified requirements. The

Contractor shall not change sources or aggregate production methods or asphalt material

mixing after approval of the job-mix except after repeat of material testing and

submission of new mix.

12.5 Construction:Unless otherwise stated in the Special Specifications or otherwise conflicting

with what is listed in this section, the construction requirements shown in item 8.5.6

Construction shall be applied to the items related to preparation of asphalt materials,

aggregates, asphalt concrete mix and joint.

The Contractor shall ensure surface preparation (any type) on which Superpave

mix will be placed. He shall clean the surface from dust, loose material and any foreign

material and apply tack coat or prime coat by the method and equipment approved by

the Engineer and in accordance with the requirements listed in this General

Specifications and the Special Specifications. The Contractor shall also fill the cracks

and patch potholes if the surface is asphalt concrete, as shown in plans and contractdocuments. The central plants used in Superpave production, shall satisfy the

requirements listed in the specification AASHTO M 156 designation for the

"Requirements of Hot Mix Asphalt Plants.

The Contractor shall haul, place and spread the Superpave asphalt concrete to

the thickness specified in plans and by the manner and equipments stated in the Special

Specifications and this General Specifications. The asphalt mix temperature during

discharge from the plant into the truck shall not be less than one hundred and sixty

(160) degrees Celsius and not greater than one hundred and eighty (180) degrees

Celsius.

All Superpave layers shall be spread and initially compacted, in the initial

coverage, in temperatures not less than one hundred and thirty five (135) degrees

Celsius. All compaction works shall be finished before the mix temperature is reduced

to less than ninety (90) degrees Celsius. The compaction shall be in the form of

consecutive or sequential passes by approved rollers. The pass is defined as the

movement of one roller in any direction. The number of passes which cover the full

width of pavement by compaction is defined as the coverage. Table (12.5.1) may be

used as guidelines for determination of the degree of compaction, roller type and

number of coverage's.

Longitudinal joints shall be compacted first, and then compaction may be started

at the lower side towards the higher side (road center line) using self propelled steel or

pneumatic rollers. The weight of each of these rollers shall not be less than ten (10) tons

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and the Contractor shall take care of these rollers, maintain and operate in the manner

which will lead to the required purpose.

Table 12.5.1: Degree of Compaction and Number of Coverage

First Alternative Second AlternativeDegree ofCompaction Roller Type

Number of

Coverage **Roller Type

Number of

Coverage **

Initial Steel Roller 1 Vibratory Roller 1

Intermediate Pneumatic Roller 4 Vibratory Roller 2 4 *

Final Steel Roller 1 - 3 Steel Roller 1 - 3

* Depends on Roller Weight** The number of coverages shall be selected on the basis of the experimental section.

The number of tires of the pneumatic roller shall not be less than seven tires and the tires shall becapable of applying an air pressure of 258 kg/cm2 or ninety (90) pounds / square inch. The air

pressure in any tire shall not vary by more than 14 kg/cm2or five (5) pounds / square inch from the

approved pressure and the weight of each tire shall not be less than 2222 Kilograms or five thousand(5000) pound.

The longitude and latitude joints shall be compacted first, after that compaction

start from edges to the road axis using mechanical steel or pneumatic rollers and their

weights must not be less than ten (10) tons and the contractor shall operate, repair and

take care about it as to achieve its purpose.

The adequate number of rollers shall be provided and the compaction shall

continue till the required field density is reached. The compaction degree shall

determine on the basis of the experimental section results as in the standard method

AASHTO T-310 or the method AASHTO T-168. The degree of compaction shall not beless than 91% of the maximum theoretical density defined by the standard method

AASHTO T-209.

12.6 Traffic Control:

The Contractor shall take the effective measures to prevent all types of traffic

from using the Superpave layers unless approved by the Engineer and he shall take the

approval of the concerned authorities in this respect and follow the requirements shown

in item 8.5.7 of this General Specifications.

12.7 Works Acceptance:

Contractor shall apply quality control for superpave asphalt concrete productionby carrying out all the required arrangements to ensure that the used materials,

construction methods and the executed works achieve the quality requirements,

indicated in the standard specifications, special specifications, these general

specifications and other contract documents.

The Ministry shall apply the quality assurance works by verifying that the

contractor has carried out quality control procedures properly either through direct

supervision of the quality control procedures or by undertaking quality assurance

procedures neutrally on representative samples and with adequate numbers to judge the

execution and to decide in accepting or not accepting the completed work according to

the principles detailed in Division 17 of this general specifications except otherwisespecified in special specification or other contract documents.

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12.7.1 Quality Control:

The Contractor shall furnish a plan for the quality control system which he will

follow during the contract period at his own expense in his laboratories, as part of the

daily work follow up, or in other independent laboratories which are approved by the

ministry, thirty (30) days prior to commencement of the asphalt concrete production for

approval. The Contractor shall not start production and construction prior to obtainingwritten acceptance of the plan by the Engineer. He shall be committed to the plan during

the contract period. That plan shall include the number, qualifications of the work staff

and a list of devices, equipments, calibration methods, finished calibration certificates

from approved authority, number of available tests, and number of samples, their weight

and frequency.

The Contractor shall conduct the quality control tests for the materials at their

source, during use, when preparing the mix design and on the site as shown In Table

(12.7.1).

The total aggregate, including fine aggregate, mineral filler and asphalt binder,

shall conform to the approved proportions in the job mix formula within the allowedtolerances listed in item 12.3.2 of this General Specifications. When these percentages

are not conforming to the approved job mix formula within the allowed tolerances, the

mix production shall be suspended for recalibration.

At least two specimens from the produced asphalt mix shall be compacted by the

gyratory compactor as in AASHTO TP-4 method. And the maximum theoretical

specific density shall be performed for each mix intended for compaction in the

laboratory as in ASTM D 2041 method and according to the frequency stated in Table

(12.7.1) at the design compaction level (Ndes) in order to ensure that the volumetric

properties of the asphalt mix are within the following limits:

- The air voids and the voids in the mineral aggregate of the produced asphalt mixshall not vary by more than one (1) percent from what has been specified in the job

mix formula.

- The voids filled with asphalt shall not vary by more than five (5) percent from whathas been specified in the job mix formula.

- The ratio of the average tension resistance of the compacted and subjected toenvironmental conditioning specimens to the average tension resistance of the

compacted specimens, not subjected to environmental conditioning shall not be less

than seventy five (75) percent as determined by AASHTO T-283 test.

-

The gyratory compaction test shall be performed at the maximum compaction level(Nmax) for each four days production to ensure that the density ratio at this level of

compaction is less than ninety eight (98) percent of the maximum theoretical

specific density (Gmm).

12.7.2 Quality Assurance :

Ministry at any time has the right to assure the quality of materials and executed

works through carrying out or ordering others under its direct supervision to select

materials and check executed works for all or part of the quality control items specified

in 12.7.1 subsection.

Ministry has the right to review contractors quality control records and comparethese statistically with its results to insure quality according to what is specified in

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division 17 of these general specifications. It has the right to inspect the contractors

laboratory and its equipments, its technical staff, methods of testing and construction

method to insure the efficiency of the contractors technical staff and equipments and

compliance of his inspection methods, testing and construction method with the

approved methods.

Table 12.7.1: Quality control procedures for Superpave asphalt concrete mixes

Work Properties Testing method

Location

of

Sampling

Sampling frequency Requirements

Asphalt

binder

Quality requirements

and PG classification

Tests indicated in

Table 12.3.1

One test In the beginning ofsupply, during the mix design

and whenever the source or mixproperties are changed.

Table 12.3.1

Consensus propertiesTests indicatedin Table 12.3.3

Table 12.3.3

Source propertiesTests indicated in

Table 12.3.4

3 tests on different samples fromeach source at source approval

and design job mix formula orwhen source is changed or whennoticing a change in constructed

works properties, and 5 tests ondifferent randomly time selected

samples for each 5000 cubicmeters from each source during

construction.

Table 12.3.4Aggregate

Specific gravity (Gsb)and

absorption

AASHTO T-19

At

Source

3 samples during mix design andone test for each week or when

mix properties are changed.

Tables from12.3.5 to

12.3.9

Aggregate gradation

(dry mix)

AASHTO

T-27

3 samples during mix design and

one test for each week or whenmix properties are changed.

Tables from

12.3.5 to12.3.9

Specific gravity (Gsb)and

absorptionAASHTO T-19

3 samples during mix design andone test for each week or when

mix properties are changed.

Tables from12.3.5 to

12.3.9

Source propertiesTests indicated in

Table 12.3.4One test each month or whenmix properties are changed.

Table 12.3.4

Materials

during

construction

Consensus propertiesTests indicated

in Table 12.3.3

One test each month or when

mix properties are changed..Table 12.3.3

Aggregate gradationand asphalt content

AASHTO

T-27/T-164T-308/T-310

At least one samples for each for

each 500 cubic meters or one foreach daily production from each

constructed layer.

Tables from

12.3.5 toTables 12.3.9

Volumetric propertiesusing Gyratory

compaction at designnumber of Gyrations

(Ndes)

AASHTO TP-4

At least three tests at approval of

design aggregate structure orwhen properties or mix

aggregate are changed and one

test for each 500 cubic metersfrom each Plant or for each

working day which is the lesser.

Section 12.3and 2.4,

Table 12.4.1and 12.4.2

Percent of max density

Gmmusing Gyratorycompaction at

maximum number of

Gyrations (Nmax)

AASHTO TP-4

One Test for every four

production days or one test foreach 500 cubic meters from each

Plant which is the less

Table 12.4.2

Asphalt mix

tests

Maximum theoretical

specific gravity (Rice)

AASHTO

T-209/

ASTM D 2041

at

Stock Piles

At least three tests at approval of

design aggregate structure orwhen properties or mix

aggregate are changed and one

test for each 500 cubic metersfrom each Plant or for each

working day which is the lesser.

Item 12.7.1

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Mi i t f M i i l & R l Aff i Ki d f S di A bi 341

Mixture sensitivity tomoisture induced

damage

AASHTO

T-283

One test when design andapproval of job mix formula or

when the mix properties arechanged.

Item 12.7.1

Compaction ASTM D-2726

one test for each 1000 squaremeters from each constructedlayer or working day which is

the lesser.

Section 12.5

Thickness ASTM D-3549

One test from each 1000 square

meters from each constructedlayer or working day which is

the lesser.

Section 12.5

Skid resistance on

surface layer

Skid resistance

measurement

Skid measurements for each

working day.Section 12.5

Surface layer roughnessRoad roughness

measurement

Using measurement methods

indicated in specialspecifications for each working

day.

Section 12.5

Constructed

works

Levels, dimensions

and, slopes

measurements.

Contractdocuments

At site

Cross section measurements

each 25 meters or 5 sectionseach 1000 square meters

whichever is greater.

Requirements

stated incontract

documents

The requirements including in division seventeen (17) in these general

specifications shall apply to accept constructed superpave asphalt concrete works. On

application of the statistical system, the elements of pay factor determination shall

include; the thickness, gradation, surface smoothness, asphalt binder content and

compaction. The number of samples and the lot amount shall be as shown in Table

(17.3.1) of this General Specifications.

The quality assurance procedures shall be applied as shown in sub item 8.5.8.2and table (8.5.6), which is concerned with compaction requirements, thickness of the

constructed asphalt concrete - as decided on plans -, aggregate gradation, asphalt binder

content and evenness of the surface layer. The allowed tolerances limits for gradation

shall be as shown in Tables (12.3.5), (12.3.6), (12.3.7), (12.3.8) and (12.3.9), and the

asphalt binder content shall be in the range 0.4 % from the approved design content.

12.8 Measurement and Payment:

Each lot quantity of the Superpave concrete layer shall be measured in cubic

meters compacted to the specified density ratio and in accordance with the thickness

shown on plans. The payment shall be according to the contract unit price or the

modified unit price per cubic meter for any constructed layer of asphalt concrete. No

measurement shall be made for quantities and areas placed outside the allowed limits

for payment purposes. Payment and prices shall be full compensation against provision

of labor, materials, equipments, tools and all other items necessary for work completion

as shown in this General Specifications and this Special Specifications.

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