Economic Evaluation of Long-Life Pavements
Description
Phase I of the study analysed the prospects for the development of an
economic basis of longer-life wearing-courses for heavily-trafficked
roads. A number of promising pavement materials were identified warranting
further investigation. Phase II of the project coordinated testing by
national testing laboratories to assess the durability of the wearing
courses. This involved small-scale testing (laboratory testing and
accelerated load testing) of the most promising pavement materials.
The proposed Phase III will coordinate full scale field trials of
epoxy asphalts and high cementitious materials on heavily trafficked
roads.
Tasks completed in Phase II
- Design and Laboratory Testing
Technical properties tested include: strength, stiffness,
water-tightness, bond strength, compatibility, workability,
resistance to shear and dynamic actions, resistance to stone
polishing, resistance to heat impact, release of dangerous
substances, aggregate properties, freeze-thaw durability,
fire resistance, capacity to bridge cracks, retention of
those characteristics after exposure to chemicals,
weathering, light, etc. Wearing courses were tested under
loading that might reflect possible future changes in policy
or demand - such as in mass limits or traffic mix. This
allowed comparisons with the performance of typical materials
used today.
- Environmental Tests
Working environment testing addressed: leaching from and wear
of the pavements surfaces during the service life, noise reduction
potential, capacity for recycling, potential for using by-products
like plastic and rubber waste.
- Accelerated Load Testing and Construction Technology
and Methods
After the laboratory testing, a limited number of the more
promised materials were subjected to medium- and large-scale
accelerated load testing, e.g. in smaller wheel tracking
devices and/or full-scale outdoor test track facilities. Before,
during and after testing the specimens/slabs for the larger
scale, devices were tested with regard to functional properties
like friction, evenness, wear, noise properties, degree of
cracking, bond to substrate, etc.
For application on longer road sections new construction
equipment and methods were developed in order to secure a low
price and satisfactory quality. Surface preparation, time
required for construction, weather restrictions, curing
conditions and hardening period before trafficking were
therefore also assessed.
- Evaluation of Results and Policy-Related Questions
Results compared with expectations and outcomes detailed in Phase I.
Results evaluated on technical grounds as well as in terms of the
impacts of possible future changes in road operating environments.
- Results
The results are presented for policy-makers in an
executive summary.
A full report will be published in 2008.
- Participants
Phase 2 of the project was undertaken by national laboratories
between 2004 and 2007 under the chairmanship of Jorgen Christensen
(Denmark).
The following countries participated in the study:
Australia, Austria, Belgium, Canada, Denmark, Finland, France,
Greece, Italy, Japan, New Zealand, Romania, Russia, Serbia and
Montenegro, Sweden, Switzerland, United Kingdom, United States.
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