1. Durable Roads NPRA Agency Research Program
Leif Bakløkk
Program Manager
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2. Increased service life and reduced annual cost
The goals of Durable Roads project are:
Increased service life and reduced annual cost
Measures we have been working with:
Ensure good workmanship in paving of asphalt surfacings
Improve material utilization and methods for production/ paving of asphalt pavements.
Introduce better methods for condition data collection and quality control.
Improve design and rehabilitation
Introduce improved requirements and specification in contracts.
Develop new manuals and guidelines
Development of knowledge by supporting PhD studies etc.
Improve knowledge on road construction:
Improved teaching material
Textbook in road technology
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3. Improvements/results from Durable Roads:
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4. Workmanship – Tack coat
Asphalt surfacing
Workmanship – Tack coat
Tack coat
Ensures good bond
Have introduced new requirements for quantity of tack coat
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5. Workmanship - Joints Asphalt surfacing
Good joints
Ensure long service life
Have introduced new requirements for voids in joints and use of restraining wheel during compaction
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6. Workmanship – Homogeneity
Asphalt surfacing
Workmanship – Homogeneity
Thermal camera
Ensures better quality
Bonus for uniform temperature during paving (IR – scanning)
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7. Workmanship - Homogeneity
Asphalt surfacing
Workmanship - Homogeneity
Laser scanner
Developed new tool for control
Variation of surface texture provides an indicator for homogeneity
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8. Introduced stricter requirements for material quality
Base and sub-base layers
Introduced stricter requirements for material quality
Aggregates
More robust requirements
New requirements for sub-base (unsorted stone no longer allowed) and improvements in frost protection design. This is implemented in the new pavement design manual, N200.
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9. New requirements for compaction of granular layers
Base and sub-base layers
New requirements for compaction of granular layers
Important part of the work
Often underestimated
New requirements in N200:
Use of GPS
Map based documentation
Stiffness/strength on the top layer
Guideline developed
Intelligent compaction is tested
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10. Wider, more robust roads
Geometric design
Wider, more robust roads
Cost/benefit analysis
Increased shoulder width
Preliminary calculations show that wider shoulders and better confinement of the pavement structure are beneficial for narrow low-trafficked roads
This is based on:
Bearing capacity at pavement edge
Rutting
Traffic safety benefits
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11. Guideline for rehabilitation
Rehabilitation/maintenance measures
Guideline for rehabilitation
New handbook
Divided into three main parts
Part A: Planning and design
Part B: Rehabilitation methods/ measures
Part C: Examples
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12. Knowledge dissemination is very important
Contribution to teaching
Knowledge dissemination is very important
Lack of students who choose road technology subjects has led to too few well-qualified personnel at all levels in the sector.
There is also too little capacity for research and development of teaching materials at colleges and universities
The need for good teaching materials is great at different places:
Inside NPRA
In the construction sector
In colleges and universities
In the technical/vocational education
Textbook in road technology
Important measure
The textbook is intended for engineering colleges but can be used for many other purposes in the NPRA and by others.
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13. Current program status
The work is in its final phase , 2015 will be the year for reporting and implementation.
Work yet to be finalized:
Completing part reports
Cost/benefit analysis of wider roads
Textbook in road technology
Final report
Implementation and transfer of results to the right persons in the organization
Publishing and dissemination
Final seminar at the technology conference 2015 (21 – 24 September)
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14. vegvesen.no/varigeveger
More information, reports, guidelines etc can be found at:
vegvesen.no/varigeveger
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15. Current Agency Research Programs
Norwegian Public Roads Administration
Current Agency Research Programs
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