Challenges and future solutions in Road Engineering. Leif Jørgen Bakløkk Norwegian Public Roads Administration

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1 Challenges and future solutions in Road Engineering Leif Jørgen Bakløkk Norwegian Public Roads Administration Via Nordica 2012

2 Content 1. Conditions and challenges today 2. Development trends Generally and in Road Engineering 3. Future solutions

3 The rehablitation challenge Much of today s road network was constructed many years ago and need rehabilitation. Rebuilding these roads to satisfy our current requirements is a big challenge. Solutions that are not optimal neither technically nor economically are often chosen for budgetary reasons.

4 Empirical basis for the structural design system The Norwegian pavement design is empirical and mainly based on the results from: AASHO Road Test Vormsund road test Both of these tests were performed in the 1960s and only little changes have been made in the design system since then. The system has performed well, but today it has limitations

5 Effective production methods Big construction machines make the work go fast and effectively Little time to adjust when unexpected conditions occur Little time to conduct appropriate quality control Little time for consolidation settlements to occur during construction phase This demands the use of robust construction materials that suit today s construction methods

6 Lack of competent professionals Many experienced professionals have left or are going to retire soon. Few young people take education in this area We have a big challenge to attract competent professionals in this area

7 Climate change More rainfall with increased effect of water and moist climate More freeze-thaw cycles in some areas Increased erosion, landslides and avalanches Roads must be built at raised elevations relative to rivers and lakes

8 More focus on the environment Warm Mix Asphalt (WMA) Recycling (less consumption of natural resources) LCA/LCC Carbon footprint Low noise pavements Rolling resistance

9 Greater demand from users Increased demand for better condition and accessibility of the road network Need/demand to use larger axle loads and tire pressures (to save fuel) Less possibility to work on the roads (Traffic disruption) Supply of road capacity has not kept pace with the rising demand for road transport (ref.: Adnan Rahman)

10 Contracts and the economy are decisive Today we see a strong focus on economy and completion time. Less emphasis is often put on the quality of workmanship. Good contracts demand good documentation and guidelines. The system of internal control is not working satisfactorily and should be followed up with client control in addition.

11 Equipement for condtion measurement and monitoring 1. Pavement condition Rutting and evenness Texture Friction Damage, cracking etc. Acoustic properties 2. Structural layers and condition Layer thicknesses Deflection/stiffness Condition and variations 3. Photo and video monitoring Pavement Roadside Now there is almost unlimited possibilities to collect data/info. The challenge is to utilize the data in a good way.

12 Development of the computer systems is going fast More measurement systems are being integrated into the same vehicle and measured at the same time Data collection speed and storage capacity increases Measurement is being conducted at traffic speed Positioning accuracy improves

13 Compaction Control CCC and GPS The use of Continuous Compaction Control and GPS is a major advance. Intelligent compaction The compaction work is being improved much with the use of Intelligent compaction where the amplitude is adjusted to the stiffness of the layer being compacted.

14 Thermal camera Thermal camera is becoming a useful tool to improve production control and obtain good homogeneity in asphalt paving. Can be used both by the contractor (to guide/correct the production) and by the road owners (quality control or as a basis for bonus).

15 Future - Equipment The development focuses on better software with automatic interpretation and analysis of data as well as better presentation of the results. Big possibilities lie in here. The control equipment will be used both for guiding the production and for quality control. Non-destructive and fast control methods will dominate in the future The development will also be marked by the integration of the control equipment into the production equipment (such as Continuous Compaction Control and thermal camera)

16 Future Performance based properties and contracts Future development will go in the direction of more utilization of performance based properties instead of detail specifications that are mostly in use today. This will also lead to simpler quality control of the work. There will also be more use of performance based contracts, bonus contracts etc. In my opinion this will contribute to more focus on good workmanship and better quality of road construction.

17 Future Performance Prediction Models Prediction and documentation of the performance of the roads will become more and more important in the future. This is related to both budgetary and technical needs: To calculate effect of performance measures, material choice etc. To make good long-term plans To calculate budget needs To document the long-term effect of investments or savings. To calculate effect of changes in loading, for example increased axle load. Reliable performance models are often the most critical part of such analyses

18 Future Analytical design systems The use analytical design systems is increasing and will continue to increase in the future Advances in material characterization and modeling and an increase in computational capacity makes it possible to apply mechanistic models in pavement structural design. Analytical design systems coupled with performance prediction models will allow better optimization of structural design and material choice Future design systems must be suited for both design of new roads and rehabilitation/strengthening Future systems must be able to easily take into account data from condition measurement equipment etc.

19 Future Robust design to enable building of durable roads Ticker road foundations and more frost protection than what we have today (costly, time consuming and difficult to change this later) Choice of materials that suit modern production methods Materials and production methods that have least possible effects on the environment (for example Warm Mix Asphalt) Updating the design systems in relation to future traffic and climatic loading.

20 Thank you for your attention!