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Publications
Pavement
AGPT04K-18
Worked Examples
Double/double Seal Carrying a High Percentage of Heavy Vehicles
Binder
Pavement
Table of Contents
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Table of Contents
1. Introduction
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1.1 Background
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1.1.1 The Nature of Sprayed Seals
1.1.2 Historical Context
1.1.3 Development of Guides to Sprayed Sealing Practice
1.2 Use of this Guide
2. Operating Environment
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2.1 General
2.2 The Managerial Environment
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2.2.1 Pavement Management Systems (PMS)
2.2.2 Maintenance Management Systems (MMS)
2.2.3 Whole-of-life Costing
2.2.4 User and Community Needs
2.2.5 Workplace Health and Safety
2.2.6 Contract Delivery and Contract Specifications
2.3 The Physical Environment
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2.3.1 Traffic
2.3.2 Existing Pavement Condition
2.3.3 Climate and Weather
3. Types of Sprayed Seal Treatments
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3.1 Categories of Sealing Treatments
3.2 Initial Treatments
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3.2.1 Prime
3.2.2 Initial Seal
3.3 Sprayed Seal (Secondary and Retreatments)
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3.3.1 Single/single Seal
3.3.2 Multiple-layer Applications
3.3.3 Aggregate Retention Seal
3.3.4 High Stress Seals (HSS1 and HSS2)
3.3.5 Extreme Stress Seal (XSS)
3.3.6 Strain Alleviating Membrane (SAM)
3.3.7 Strain Alleviating Membrane Interlayer (SAMI)
3.3.8 Fibre Reinforced Seal (FRS)
3.3.9 Geotextile Reinforced Seal (GRS)
3.3.10 Cape Seal
3.4 Other Treatments
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3.4.1 Variable Rate Spraying
3.4.2 Salt-affected Pavements
3.4.3 Surface Enrichment and Rejuvenation Treatments
3.4.4 High-friction Surface Treatment
3.4.5 Acrylic Oil Resistant Seal
3.4.6 Coloured Surface Treatment
3.4.7 Dust Laying
4. Selection of Treatments
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4.1 Overview
4.2 Purpose of Sprayed Seals
4.3 Distress Modes
4.4 Selection Process
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4.4.1 Stakeholder Needs
4.4.2 Performance Requirements
4.4.3 Whole-of-life Costs
4.5 Selection of Aggregate
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4.5.1 Aggregate Properties
4.5.2 Aggregate Size
4.6 Binders
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4.6.1 Conventional Bitumen
4.6.2 Multigrade Bitumen
4.6.3 Polymer Modified Binder (PMB)
4.6.4 Bitumen Emulsion
4.6.5 Effect of Spraying Conditions and Delivery System on Binder Selection
4.7 Selecting a Prime
4.8 Selecting an Initial Seal
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4.8.1 Binder Type
4.8.2 Aggregate Size
4.9 Selecting Speciality Treatments
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4.9.1 Variable Binder Spray Rates
4.9.2 Geotextiles
4.10 Selecting a Sprayed Seal
5. Design Method
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5.1 Principles
5.2 Design Traffic
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5.2.1 Traffic Data
5.2.2 Accuracy of Data
5.2.3 Distribution of Traffic
5.2.4 Procedure for Determining Design Traffic
5.2.5 Equivalent Heavy Vehicle (EHV(%))
5.2.6 Short-term Traffic Variations
5.2.7 Access Roads to Sites such as Quarries and Mining Locations
5.3 Aggregate Size and Shape
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5.3.1 Average Least Dimension (ALD)
5.3.2 Flakiness Index
5.4 Surface Texture
5.5 Design Process
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5.5.1 Single/single Sprayed Seal
5.5.2 Double/double Sprayed Seal
5.5.3 Initial Treatments
5.5.4 Other Seals
6. Seal Design Input Parameters
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6.1 Voids Factor
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6.1.1 Basic Voids Factor
6.1.2 Adjustments to the Basic Voids Factor
6.1.3 Design Voids Factor
6.2 Binder Application Rate
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6.2.1 Basic Binder Application Rate (Bb)
6.2.2 Allowances Applied to the Basic Binder Application Rate
6.2.3 Embedment Allowance (Ae)
6.2.4 Binder Absorption Allowance (Aba)
6.3 Binder Factor
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6.3.1 Single/single Seals
6.3.2 Double/double Seals
6.4 Design Binder Application Rate (Bd)
6.5 Geotextile Reinforced Seals (GRS)
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6.5.1 Binder Fabric Retention Allowance
6.5.2 Bond Coat
6.6 Fibre Reinforced Seals (FRS)
6.7 Aggregate Spread Rate
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6.7.1 Influence of ALD
6.7.2 Influence of Traffic
6.7.3 Single/single Seals
6.7.4 Double/Double Seals
7. Construction
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7.1 Pavement/Surface Preparation
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7.1.1 Primes
7.1.2 Initial Seals
7.1.3 Reseals
7.2 Sprayed Sealing Operations
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7.2.1 Aggregate Loading and Treatment
7.2.2 Spraying of Binder
7.2.3 Aggregate Spreading
7.2.4 Rolling
7.2.5 Sweeping
7.2.6 Opening to Traffic
7.3 Construction and Maintenance Scheduling
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7.3.1 Primes
7.3.2 Initial Seals
7.3.3 Sprayed Seals
References
Appendix A Photographic Examples of Pavement Preparation
Appendix B Austroads Vehicle Classification
Appendix C Worked Examples
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Appendix C 1 Single/single Reseal – 14 mm HSS1
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Appendix C 1.1 Job Details
Appendix C 1.2 Traffic Data
Appendix C 1.3 Aggregate
Appendix C 1.4 Binder
Appendix C 1.5 Seal Design
Appendix C 2 Double/double Seal Carrying a High Percentage of Heavy Vehicles
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Appendix C 2.1 Job Details
Appendix C 2.2 Traffic Data
Appendix C 2.3 Aggregate
Appendix C 2.4 Binder
Appendix C 2.5 Seal Design
Appendix C 3 Single/single SAM Reseal
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Appendix C 3.1 Job Details
Appendix C 3.2 Traffic Data
Appendix C 3.3 Aggregate
Appendix C 3.4 Binder
Appendix C 3.5 Seal Design
Appendix C 4 Geotextile Reinforced Seal (GRS)
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Appendix C 4.1 Job Details
Appendix C 4.2 Traffic Data
Appendix C 4.3 Aggregate
Appendix C 4.4 Binder
Appendix C 4.5 Seal Design
Appendix C 5 Quarry Access Road
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Appendix C 5.1 Job Details
Appendix C 5.2 Traffic Data
Appendix C 5.3 Aggregate
Appendix C 5.4 Binder
Appendix C 5.5 Seal Design
Appendix D Determination of Maximum Pavement Temperature
Appendix E Guidance to Field Application of PMBs and Multigrade Bitumens
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Appendix E 1 Adhesion and Cohesion Characteristics
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Appendix E 1.1 Use of Adhesion Agent
Appendix E 1.2 Aggregate Precoating
Appendix E 1.3 Cutting Back
Appendix E 1.4 Ambient Conditions
Appendix E 1.5 Spraying of Binder, Spreading and Rolling of Aggregates
Appendix E 1.6 Checking Adhesion
Appendix E 2 Cutting Back PMB or Multigrade Bitumen
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Appendix E 2.1 Safety
Appendix E 2.2 Pavement Temperature Assessment
Appendix E 2.3 Type of Cutter Oil
Appendix E 2.4 Selecting the Proportion of Cutter Oil
Appendix F Summary of Tables and Design Factors
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Appendix F 1 Design Process
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Appendix F 1.1 Single/single Sprayed Seal
Appendix F 1.2 Double/double sprayed seal
Appendix F 2 Abbreviations
Appendix F 3 Voids Factor
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Appendix F 3.1 Basic Voids Factor
Appendix F 3.2 Adjustments to the Basic Voids Factor
Appendix F 3.3 Design Voids Factor
Appendix F 4 Binder Application Rate
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Appendix F 4.1 Basic Binder Application Rate (Bb)
Appendix F 4.2 Allowances Applied to Basic Binder Application Rate
Appendix F 4.3 Embedment Allowance (Ae)
Appendix F 5 Binder Factor
Appendix F 6 Design Binder Application Rate (Bd)
Appendix F 7 Aggregate Spread Rate
Tables
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Table 3.1: Advantages and disadvantages of initial seals, and prime and seals
Table 3.2: Initial treatments for salt- affected granular pavements
Table 4.1: Summary of the needs of the principal stakeholder groups in surfacing selection
Table 4.2: Effectiveness of sprayed seal, microsurfacing and combined resurfacing treatments on existing surfacing characteristics
Table 4.3: Generally recommended aggregate sizes for sprayed seal treatments
Table 4.4: Recommended pavement temperatures for various binders
Table 4.5: Recommended maximum permissible gradients for various binders
Table 4.6: Preliminary guide to the selection of initial seals
Table 4.7: Preliminary guide to seal selection
Table 5.1: Estimation of design traffic from AADT for single carriageways
Table 5.2: Estimation of design traffic from AADT for dual carriageways
Table 5.3: Double/double seal design surface texture allowance and time between seals
Table 5.4: Guide to grades and application rates of primer
Table 6.1: Adjustment to basic voids factor for aggregate shape (Va)
Table 6.2: Adjustment (Vt) to basic voids factor for traffic effects
Table 6.3: Surface texture allowance for existing surfacing, As (L/m2)
Table 6.4: Binder factors for single/single seals
Table 6.5: Binder factors for double/double seals
Table 6.6: Typical binder retention allowance for geotextile reinforced seals
Table 6.7: Typical binder allowances for glass fibre
Table 6.8: Aggregate spread rates for single/single seals
Table 6.9: Aggregate spread rates for scatter coat
Table 6.10: Aggregate spread rates for SAMI
Table 6.11: Double/double seal design aggregate spread rates for the first application seal, with little or no trafficking between applications
Table 6.12: Double/double seal design aggregate spread rates for second application, little or no trafficking between applications
Table C 1: Distribution of traffic
Table C 2: Vehicle volume by lane
Table C 3: Design calculations
Table C 4: Design calculations
Table C 5: Design calculations
Table C 6: Design calculations
Table C 7: Design calculations
Table D 1: Pavement surface temperature
Table D 2: T<sub>max</sub> by latitude
Table D 3: T<sub>max</sub> for Australian capital cities
Table D 4: T<sub>max</sub> for Australian locations
Table E 1: Guide to cutting practice for PMBs
Table F 1: Adjustment to basic voids factor for aggregate shape (Va)
Table F 2: Adjustment (Vt) to basic voids factor for traffic effects
Table F 3: Surface texture allowance for existing surfacing, As (L/m2)
Table F 4: Binder factors for single/single seals
Table F 5: Binder factors for double/double seals
Table F 6: Aggregate spread rates for single/single seals
Table F 7: Aggregate spread rates for scatter coat
Table F 8: Aggregate spread rates for SAMI
Table F 9: Double/double seal design aggregate spread rates for first application seal, little or no trafficking between applications
Table F 10: Double/double seal design aggregate spread rates for second application, little or no trafficking between applications
Figures
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Figure 1.1: Sprayed seals are an important element of the Australasian road system
Figure 1.2: Spraying bituminous binder
Figure 1.3: Spreading aggregate
Figure 1.4: Applying sprayed seal binder circa 1960s
Figure 1.5: Previous guides to sprayed sealing practice
Figure 2.1: High-volume traffic on a sprayed seal pavement
Figure 2.2: Low-volume traffic on a sprayed seal pavement
Figure 2.3: Sprayed seal pavement in a dry, hot environment
Figure 2.4: Sprayed seal pavement in a damp, cool environment
Figure 3.1: Sprayed seal life-cycle flow chart
Figure 3.2: Prime
Figure 3.3: Initial seal
Figure 3.4: Single/single seal
Figure 3.5: Double/double seal
Figure 3.6: Single/single seal with a scatter coat
Figure 3.7: Dry matting
Figure 3.8: Inverted seal
Figure 3.9: Strain alleviating membrane
Figure 3.10: Strain alleviating membrane interlayer
Figure 3.11: Application of binder and fibre for fibre reinforced seal
Figure 3.12: Geotextile reinforced seal
Figure 3.13: Cape seal
Figure 3.14: High-friction surface treatment
Figure 3.15: Coloured surface treatment incorporating epoxy resin binder and synthetic aggregate
Figure 3.16: Dampening down dusty surface
Figure 3.17: Dust laying techniques for other engineering works
Figure 4.1: Distress modes for sprayed seals
Figure 4.2: General relationship between initial costs and effectiveness for alternative sprayed seal treatments
Figure 5.1: Three-dimensional shape of a sealing aggregate particle
Figure 5.2: Flow chart for design of a single/single seal
Figure 5.3: Flow chart for design of a double/double seal
Figure 6.1: Basic voids factor (Vf) for single/single seal – traffic volume 0 to 500 vehicles/lane/day
Figure 6.2: Basic voids factor (Vf) for single/single seal – traffic volume 500 to 10 000 vehicles/lane/day
Figure 6.3: Basic voids factor (Vf) for double/double seal – traffic volume 0 to 500 vehicles/lane/day
Figure 6.4: Basic voids factor (Vf) for double/double seal – traffic volume 500 to 15 000 vehicles/lane/day
Figure 6.5: Embedment allowance for initial treatments
Figure 7.1: Multi-tyred roller
Figure A 1: Examples of well-prepared granular pavements
Figure A 2: Examples of marginal cases of prepared granular pavements
Figure A 3: Examples of poorly prepared granular pavements
Figure B 1: Austroads vehicle classifications
Figure C 1: Carriageways of duplicated highway
Figure F 1: Flow chart for design of a single/single seal
Figure F 2: Flow chart for design of a double/double seal
Figure F 3: Basic voids factor (Vf) for single/single seal – traffic volume 0 to 500 vehicles/lane/day
Figure F 4: Basic voids factor (Vf) for single/single seal – traffic volume 500 to 10 000 vehicles/lane/day
Figure F 5: Basic voids factor (Vf) for double/double seal – traffic volume 0 to 500 vehicles/lane/day
Figure F 6: Basic voids factor (Vf) for double/double seal – traffic volume 500 to 15 000 vehicles/lane/day
Figure F 7: Embedment allowance for initial treatments
Appendix C 2.4 Binder
A C170 binder will be used for this seal. The binder factor (BF) is 1.0 (
Table 6.5
).
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Appendix C 2.3 Aggregate
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Appendix C 2.5 Seal Design
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