Meet our course experts.

Steve Patrick

Principal Engineer

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John Esnouf

Expert Advisor - Bitumen Seals

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Brendan Williams

Senior Engineer

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Johan Cronje

Principal Engineer

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Course Description

Some courses teach the guide. This one is taught by the people behind it.

Learn sprayed-seal selection and design directly from the experts who helped shape the guidance – and have spent decades applying it.

NTRO’s Selection and Design of Sprayed Seals course is developed and delivered in person by national sprayed-sealing experts with deep involvement in Austroads guidance, including the Guide to Pavement Technology Part 4K: Sprayed Seals.

Steve Patrick literally “wrote the book”, authoring its 2018 edition alongside updates to initial-treatment and double/double design methods. John Esnouf brings more than 50 years of Victorian road-authority experience across construction supervision, sprayed-seal technology, technical advice and surfacing policy.

Learn face to face with NTRO specialists, ask detailed questions and work through the practical judgement behind sprayed-seal design.

Ask why the method takes a particular approach. Discuss how to apply it to your site. Explore what to do when the job bears little resemblance to the tidy example in the notes.

Rebuilt around the latest sprayed-seal technology, standards and field practice, the program develops your capability through three progressive units:

Unit 1: Fundamentals of Sprayed Sealing

Build your understanding of treatment selection, materials and specifications.
Follow pavement preparation and construction through spraying, spreading, rolling and aftercare, then examine common defects, safety and environmental considerations.

Unit 2: Intermediate Selection and Design of Sprayed Seals

Work through single/single and double/double designs using traffic counts, aggregate properties and site information.
Calculate application rates, apply allowances for texture, absorption and embedment, and explore initial seals and strain alleviating membrane interlayers beneath asphalt.

Unit 3: Advanced Selection and Design of Sprayed Seals Certification

Extend your skills to geotextile seals, quarry and mine access roads, seasonal grain-harvest traffic and other demanding applications.
Apply your knowledge through practical worked examples and an assessed design workshop and assignment, providing a clear pathway to NTRO certification as a sprayed-seal designer.

Throughout the course, connect the calculations with the judgement behind them: whether a treatment is suitable, which assumptions need checking and whether the application rates make sense for the conditions.

NTRO’s experts also host Austroads’ sprayed seals webinar program, which attracts hundreds of industry participants. This course gives you the opportunity to learn with that expertise in the room, ask follow-up questions and work through the decisions in detail.

Enrol now and strengthen your ability to select, design and review sprayed-seal treatments.

Course structure

Unit 1 – Fundamentals of Sprayed Sealing

Understand sprayed-seal functions, treatment types and materials. Explore selection principles, pavement preparation, construction, safety, environmental considerations and common defects.

Unit 2 – Intermediate Selection and Design of Sprayed Seals

Apply the design method through guided single/single and double/double examples. Work with traffic data, aggregate properties, voids factors, binder factors and site allowances. Examine initial seals, residual-rate calculations and SAMIs.

Unit 3 – Advanced Selection and Design of Sprayed Seals Certification

Review and extend design skills through realistic road scenarios. Explore geotextile seals, quarry and mine access roads, seasonal heavy-vehicle loading and other specialist treatments. Complete the design workshop and assessment assignment.

Learning outcomes

Across the three-unit program, participants will develop the ability to:

Explain how treatment types, materials, pavement preparation and construction influence sprayed-seal performance.
Evaluate treatment suitability using traffic, pavement condition, climate and service requirements.
Interpret aggregate test reports and traffic data, including lane distribution and equivalent heavy vehicle calculations.
Calculate binder and aggregate application rates for single/single, double/double, initial-seal and SAMI treatments.
Apply site allowances and extend design calculations to geotextile seals and demanding heavy-vehicle applications.
Review design assumptions, identify limitations and prepare design responses for assessment.

Topics Covered

Unit 1 – Fundamentals of Sprayed Sealing

Purpose, performance and limitations of sprayed seals
Single/single, multiple-application and specialist treatments
Primes, initial seals, secondary treatments and retreatments
Conventional bitumen, polymer-modified binders, crumb rubber and emulsions
Aggregate properties, shape, average least dimension and durability
Cutter oils, adhesion agents and aggregate precoat
Traffic, pavement condition and treatment selection
Binder and aggregate application-rate principles
Basecourse preparation and suitable surface finishes
Resealing preparation, repairs and corrective treatments
Spraying equipment, aggregate spreading, rolling and sweeping
Traffic management and opening completed works
Safety hazards and environmental considerations
Flushing, stripping, cracking and potholes: causes and potential treatments

Unit 2 – Intermediate Selection and Design of Sprayed Seals

Treatment selection, effectiveness and site suitability
Aggregate test reports, size selection and spread-rate calculations
Traffic counts, vehicle classifications and lane distribution
Equivalent heavy vehicle calculations
Basic and adjusted voids factors
Binder selection, binder factors and modified application rates
Surface texture measurement and allowances
Binder absorption and aggregate embedment allowances
Single/single design methodology and worked example
Double/double design methodology and worked example
Design differences across traffic lanes, overtaking lanes and shoulders
Initial-seal selection for traffic, climate and pavement conditions
Initial-seal design and worked calculations
Residual binder rates and cutback or emulsion product application rates
SAMI binder and aggregate design requirements
Reviewing calculated rates against site conditions and comparable works

Unit 3 – Advanced Selection and Design of Sprayed Seals Certification

Review and application of single/single design methodology
Comparing high-stress seal and strain alleviating membrane options
Double/double design for variable traffic and surface conditions
Identifying separate design sections within a road project
Wheel-path, centreline, shoulder and overtaking-lane considerations
Geotextile-reinforced seal selection, applications and limitations
Geotextile binder-retention allowances and design calculations
Geotextile preparation, bond coats and construction considerations
Quarry and mine access-road design
Nominal design-traffic adjustments for high equivalent heavy vehicle loading
Seasonal grain-harvest traffic and other short-term loading changes
Channelised, slow-moving and climbing-lane traffic effects
Delayed second-coat applications and design adjustments
Triple-coat seals and the limitations of available design guidance
Rural airstrip sealing and application-specific guidance
Armour-coats for pavements at risk of aggregate embedment
Reviewing treatment suitability, assumptions and final application rates
Practical design workshop and three-question certification assignment

This course is for:

The program is designed for people who select, specify, design, procure, supervise or manage sprayed-seal works, including:

Road-authority and local-government personnel
Pavement, materials and road engineers
Consultants and road designers
Project, contract and works managers
Asset and maintenance managers
Site supervisors and technical specialists
Road-construction contractors
Operational and production personnel

Unit 1 suits participants seeking foundation knowledge or a refresher. Units 2 and 3 suit those who calculate, review or take responsibility for sprayed-seal designs.