Opening session
With around 370 delegates, the Sprayed Sealing Conference in Adelaide, South Australia was a great success. Visit the photo gallery for pictures.
Rick van Barneveld (Chief Executive, Transit New Zealand) gave the keynote address entitled ‘an Ode to Hanson’.
F M Hanson was the New Zealander who, in 1934, put sprayed sealing on a scientific basis through his experimentation and careful observations of on-road performance.
The issues which faced Hanson in 1934 are remarkably similar to those facing engineers today.
Sharing our knowledge
John Oliver of ARRB outlined some major issues facing the sprayed sealing community. These included:
- ever increasing traffic volumes and axle loadings
- the loss of experienced sealing practitioners resulting in a worldwide shortage
- peak oil, and thus peak bitumen and its future availability, price and quality
- greenhouse gas minimisation measures and their effect on the construction industry.
These issues are a major challenge which road construction agencies and industry must address. One solution is to cooperate, both within each country and internationally, by sharing knowledge and making maximum use of the expertise that remains.
ARRB Achievement Award
An ARRB Achievement Award was presented to Walter Holtrop in recognition of his
- contribution to sprayed seal technology over the past 40 years
- involvement in research and development
- dedication to training and professional development.
Technical sessions
The first session, on national practice, featured presenters from Australia, New Zealand, South Africa and the United Kingdom. It provided a good background for the remainder of the conference which had sessions covering:
- Sealing practice
- Selection and treatment
- Materials and equipment
- Contract and legal
- Design
- Testing.
Conference workshop
A workshop was held on the last day to look at issues which had been identified during the conference. The most important are shown below:
Technical issues
- Withstanding horizontal (shear) and vertical loading
- Changing traffic compositions
- Pavement structure, surface preparation and embedment
- Operational effects in delivering design
- Extending the sealing ‘season’
- Underperforming primes and primerseals
- Binder choice vs climate and risk assessment.
Knowledge sharing
- Skills shortage in both public and private sectors
- Promotion of the industry as a career
- Glossary – international variations in sealing terminology can lead to misunderstandings
- Staff secondment – public/ private
- More ‘best practice’ forums
- Training courses
- Using the procurement process to encourage training.
Global issues
- Sealing industry response to emissions/ total energy audits
- Life cycle analysis vs alternatives
- Critical resources – e.g. water usage/recycling
- Reduced tolerance of failures
- Extended life from existing assets
- Bitumen alternatives/ bitumen extenders
- Increased demand for sprayed seals to reduce material wastage in maintaining unsealed roads and surface motorways as asphalt increases in cost
- Reseal intervention points / network optimisation.
Addressing the issues
The workshop also considered how these matters might be addressed. Sustainability, in the face of environmental challenges, was seen as a good descriptor of the most important issues facing road agencies and the construction industry.
- How can the sprayed sealing industry contribute to sustainability?
- Global alliance with sprayed sealing community
- Global strategic model
- Funding?
- Resources?
- Develop topics and prioritise issues globally
- Mechanism needed for international cooperation among principal sealing countries (Australia, South Africa and New Zealand) and others
- Austroads a possibility – it already covers Australia and New Zealand, and correspondence arrangements with South Africa should be developed
- Establish a knowledge exchange hub as an ARRB project
- Utilise existing forums such as PIARC, TREx, etc.
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