This manual has been prepared as a practical guide for asphalt technicians in the construction and inspection of asphalt pavements. It is intended to serve as a basic introduction to asphalt construction for the new technician as well as a reference source to those with considerable experience. While it is fully recognized that this manual alone cannot make a person a totally competent asphalt technician, it should provide the basic knowledge and direction for one truly interested in becoming qualified, to do so.

The terms “technician”, “inspector” and “contractor” are used throughout the manual. Generally, when reference is made to the technician, both the Contractor's representative and the buyer's (NCDOT) representative are implied.  Where reference is made to either the “inspector” or the “contractor”, then either the buyer's (NCDOT) or the contractor's representative, respectively, are specifically implied.

The information in this manual is generally compatible with current North Carolina Department of Transportation specifications and procedures, however, it does not override the provisions and specifications of a given contract. While the Department utilizes both English and Metric specifications, this manual is primarily written in English units with the Metric equivalent immediately following in parenthesis. The technician should always thoroughly review the specifications and provisions of a given contract and in the event of conflicts with this manual, the contract specifications will always govern.

Many competent men and women serve as Asphalt Technicians in North Carolina; however, in this manual only masculine pronouns are used in reference to Technicians, Inspectors and Contractors. This convention is used to avoid awkwardness in writing style and in no way is intended to reflect sexual bias on the part of the writers.
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The North Carolina Department of Transportation would like to express appreciation to the Asphalt Institute for their permission to use quotations, graphs, illustrations and other literature in the preparation of this manual.

Appreciation is also expressed to the Barber-Greene Company, Cedarapids Manufacturing Company, Blaw-Knox, USA, Galion Company, Dynapac and other equipment manufacturers for the use of their illustrations and information. Use of specific trade names or manufacturers' illustrations does not imply endorsement by the Department. These are used solely because they are considered necessary in meeting the objective of this manual.

The Department also expresses appreciation to the Florida Department of Transportation, the Virginia Department of Highways and Transportation, the Carolina Asphalt Pavement Association, the Federal Highway Administration and others for the use of their materials in the preparation of this manual.

SECTION 1: QUALITY MANAGEMENT SYSTEM (QMS) FOR ASPHALT PAVEMENTS

General 1-1

Contractor's Quality Control Plan 1.2

Asphalt QMS Technician Qualifications and Certifications 1.3

 
General 1.3.1
Purpose of Inspection and Testing 1.3.2
DOT Technician's Authority 1.3.3
DOT Technician's Relationship with Contractor 1.3.4
Qualifications of QA/QC Technicians 1.3.5
QMS Technician Requirements 1.3.6
NCDOT Asphalt Technician Certification Program 1.3.7
NCDOT Asphalt Technician Certification - Enrollment Procedures 1.3.8

Introduction 2.1

General Description of Asphalt Paving Materials / Pavements 2.2

Technician Responsibilities 2.3

Asphalt Materials 2.4

 
-Refining Crude Petroleum 2.4.1
-Classification and Grading of Paving Asphalts 2.4.2
-Asphalt Binder 2.4.3
-Emulsified Asphalts 2.4.4
-Characteristics of Asphalt Binders 2.4.5
-Testing the Properties of Asphalts 2.4.6
-Specific Gravity of Asphalt Binder 2.4.7
-Asphalt Additives 2.4.8
-Asphalt Binder Storage 2.4.9
-Delivery and Acceptance of Asphalt Materials 2.4.10
-Temperature-Volume Relationships of Asphalts 2.4.11


Mineral Aggregates 2.5

 
Introduction 2.5.1
-Sources of Aggregates 2.5.2
-Evaluating the Quality of Aggregates 2.5.3

Designing an Asphalt Pavement Structure (Thickness) 3.1

Superpave Asphalt Mix Types 3.2

Pavement Layer Depth Guidelines (For Pavement Design Purposes) 3.3

Superpave Application Rates of Spread per inch (mm) Depth 3.4

Typical Superpave Single Layer Depths / Rates 3.5

Typical Asphalt Binder Contents 3.6

Layer Coefficients 3.7

Introduction 4.1

Purposes of Mix Designs 4.2

Performance Characteristics Considered in Mix Design 4.3

The Superpave Mix Design System 4.4

NCDOT Mix Design Procedures 4.5

The Job Mix Formula 4.6

NCDOT "Master" Job Mix Formula Procedures 4.7

Composition of Recycled Mixtures (JMF) 4.8

Project File Job Mix Formula Procedures 4.9

Basic Operation of an Asphalt Plant 5.1

Types of Asphalt Plants 5.2

Certification of Asphalt Plants 5.3

Asphalt Plant Specification Checklist 5.4

Batch Plant Operations and Components 5.5

Drum-Mix Plant Operations and Components 5.6

Introduction of Anti-Strip Additive at Drum or Batch Plants 5.7

Introduction of Anti-Strip Additive at Binder Supplier's Terminal 5.8

Department of Agriculture & Consumer Services(NCDA & CS) Scales Certification 5.9

General Requirements 6.1
 
Asphalt Binder Storage and Handling 6.1.1
Asphalt Mix Temperature Requirements 6.1.2


Aggregate Storage 6.2

Aggregate Cold Feed System 6.3

Calibration of Cold Feed Blend Ratios 6.4

Batch Plant Operations 6.5
 

-Calibration of Asphalt Plant Scales, Weigh Bridges & Meters 6.5.8


Drum Mix Plant Operations 6.6
 

-Weight Measurement of Aggregate & RAP/RAS (Quarterly Calibration) 6.6.3
-Asphalt Binder Meter System (Quarterly Calibration) 6.6.4
-Anti-Strip Additive Meter System (Monthly Calibration) 6.6.5


Segregation of Plant Mixes 6.7

Scales and Public Weighmaster 6.8
 

Weigh Tickets 6.8.1


Hauling of Asphalt Mixtures 6.9

Pollution Control Equipment 6.10

Safety Requirements 6.11

Production Consistency/Automatic Equipment 6.12

Introduction - Sampling and Testing 7.1

Superpave Field Laboratory 7.2
 

QC Lab Required Equipment List For Superpave Testing  7.2.1
QMS Lab Equipment Calibration Requirements  7.2.2


Quality Control (QC) Minimum Sampling and Testing Schedule 7.3

Mix Verification, JMF Adjustments, and Corrective Action Procedures 7.4
 

Mix Verification Requirement  7.4.1
Allowable Mix Adjustments 7.4.2
Control Charts 7.4.3
Individual Test Exceeding Individual Test Limits  7.4.6A
Moving Average Exceeding Warning Limits  7.4.6B
Moving Average Exceeding Moving Average Limits  7.4.6C


Sampling Procedures 7.5

Test Procedures 7.6

Test Method for Sieve Analysis of Fine and Coarse Aggregates 7.7

Moisture Content of Aggregate by Drying 7.8

Sieve Analysis of Recovered Aggregate 7.9

Asphalt Binder Content Control Options 7.10
 

Standard Method of Test for Binder Content of Hot Mix Asphalt by Ignition Method 7.10.1
Quantitative Extraction of Asphalt Binder From Hot Mix Asphalt 7.10.2


Superpave Gyratory Compactor Field Test Procedure 7.11

Maximum Specific Gravity (G_mm) of Asphalt Paving Mixtures 7.12
 

Standard Test Method for Theoretical Maximum Specific Gravity and Density of Asphalt Paving Mixtures 7.12.2(a)

Standard Test Method for Theoretical Maximum Specific Gravity and Density of Asphalt Paving Mixtures Using Vacuum Sealing Method 7.12.2(b)


Bulk Specific Gravity of Compacted Asphalt Mixtures 7.13

Tensil Strength Ratio Test (TSR)  7.14

Determination of Drain Down Characteristics in Uncompacted Asphalt Mixtures  7.15

QMS Calculations 7.16
 

-Calculating Voids in Total Mix (VTM) 7.16.2
-Calculating Voids in Mineral Aggregate (VMA) 7.16.3
-Calculating Voids Filled with Asphalt (VFA) 7.16.4
-Calculating Aggregate Effective Specific Gravity 7.16.5
-Calculating Dust / Effective Binder Ratio (P_0.075/ P_be) 7.16.6
-Calculating Percent Gmm @ Nini 7.16.7
-Calculating Percent Gmm @ Ndes 7.16.8


Allowable Retesting for Mix Deficiencies 7.17
 

Guidelines for Retests of Mix Deficiencies 7.17.1


Quality Assurance (QA) Sampling and Testing 7.18
 

Verification Sampling and Testing Guidelines for Plant Mix 7.18.1

Hot Mix Recycling 8.1

Milling of Asphalt Pavements 8.2

Quality Control, Handling & Processing of RAP/RAS Material 8.3

Hot-Mix Recycling Methods 8.4

Plant Calculations and Control For Recycled Mixes 8.5

Composition of Recycled Hot Mix Asphalt 8.6

Compensation for Recycled Hot Mix Asphalt Pavements 8.7

Introduction 9.1
 
The Asphalt Distributor 9.1.1
 
Asphalt Delivery Tickets for Emulsified Asphalts  9.1.2


Prime Coat 9.2
 

Grades, Application Rates and Temperatures for Prime Coats 9.2.1


Tack Coats 9.3
 

Tack Coat Application Rates and Temperatures 9.3.2


Hot Mix Placing and Compaction Operations - General 9.4
 

Weather, Temperature and Seasonal Limitations  9.4.3
 
 
Spreading and Finishing of Asphalt Pavements 9.5
• Incidental Tools
• Asphalt Distributor
• Haul Trucks
• Asphalt Paver
The Placing Operation 9.6
 
Compaction of Asphalt Pavements 9.7
 
The Need for Compaction 9.7.1
Compaction Specifications - NCDOT 9.7.2
Roller Types 9.7.3
 
Rolling and Compaction Procedures 9.8
 
Factors Affecting Compaction 9.8.1
 
Constructing Transverse Joints 9.9
 
Constructing Longitudinal Joints 9.10

Significant Decimals for Roadway Calculations 9.11

SECTION 10: INSPECTION AND TESTING OF ASPHALT PAVEMENTS

 
Roadway Inspection and Testing of Asphalt Pavements - General 10.1
 
Inspection of Equipment - General  10.1.1
Checklist for QA/QC Roadway Technicians 10.1.2
Visual Inspection of the Mix (Plant & Roadway) 10.1.3
Determination of Rate of Spread and Tonnage Required 10.1.5
Temperature of the Mix at Roadway 10.1.6
Segregation of Mixes on the Roadway 10.1.7
Checking the Mat Cross-Slope and Thickness 10.1.8
Surface Texture 10.1.9


Pavement Smoothness 10.2
 

Final Surface Testing 10.2.1
Calibration of the Straightedge 10.2.2
Determination of the Cumulative Straightedge Index 10.2.3


Limited Production Policy for Unsatisfactory Laydown 10.3

Pavement Density QMS Testing Procedures - General  10.4

 
Density Testing Methods 10.4.1
Minimum Density Requirements 10.4.2
Determination of "Lots" 10.4.3
Density Control Sampling and Testing Frequencies 10.4.4
Determining Random Sample Locations - General 10.4.5
Procedures for Placing and Obtaining Core Samples - General 10.4.6


Nuclear Gauge Density Quality Control (QC)  10.5
 

Nuclear Density QC Procedures - General 10.5.1
Location of Nuclear Control Strips 10.5.2
Frequency of  QC Nuclear Control Strips 10.5.3
Numbering of  Nuclear Control Strips 10.5.4
Construction of Nuclear Control Strips (QC Procedures) 10.5.5
Core Samples from Nuclear Control Strips 10.5.6
Determination of QC Nuclear Control Strip Target Density 10.5.7
Establishment of Nuclear QC Test Sections 10.5.8
Testing a QC Nuclear Test Section 10.5.9
Numbering Nuclear QC Test Sections 10.5.10
Reporting Nuclear QC Test Sections (M&T 516 QC) 10.5.11


Nuclear Density Control Quality Assurance (QA) 10.6
 

General 10.6.1
Quality Assurance (QA) Nuclear Control Strip Procedures 10.6.2
Quality Assurance (QA) Nuclear Test Section Procedures (Comparison / Re-Test) 10.6.3
Quality Assurance (QA) Nuclear Test Section Procedures (Verification) 10.6.4


Core Sample Density Quality Control (QC)  10.7
 

Core Sample Density Control - General 10.7.1
Core Sample QC Control Strip Requirements and Procedures 10.7.2
Numbering of Core Sample Control Strips and Core Samples 10.7.3
Construction of Core Sample Control Strips (QC Procedures) 10.7.4
Determination of QC Core Sample Control Strip Density 10.7.5
Establishment of QC Test Sections 10.7.6
Determining Random Sample Locations for QC Core Sample Density Testing  10.7.7
Testing a Core Sample Test Section (QC) 10.7.8
Numbering Quality Control (QC) Core Samples 10.7.9
Check Core Samples 10.7.10
Numbering Quality Control (QC) Check Core Samples 10.7.11
Reporting Core Sample Control (QC) Testing Sections (Form QC-5 Rev.) 10.7.12


Quality Assurance (QA) Core Sample Density Control 10.8
 

Quality Assurance (QA) Test Section Procedures (Comparison) 10.8.1
Quality Assurance (QA) Test Section Procedures (Verification) 10.8.2


Acceptance of Density (Nuclear Gauge and/or Core Sample Control 10.9
 

Nuclear and Core Sample Density Control Limited Production Procedures 10.10
 

Independent Assurance (IA) Sampling and Testing for Density Control 10.11
 

General 11.1

Records and Report Documentation 11.2

Retention of QMS Forms 11.3

Falsification of Records 11.4

Summary of All Superpave QMS Forms