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Roads and Works Conference

Roads and Works Conference. Materials for Unsealed Roads – Developments in testing, additive/blending protocols and its place in Asset management . Rod Ellis. August 2012. Introduction. Local Government Research and Development Scheme 2009 -2012

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Roads and Works Conference

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  1. Roads and Works Conference Materials for Unsealed Roads – Developments in testing, additive/blending protocols and its place in Asset management Rod Ellis August 2012

  2. Introduction • Local Government Research and Development Scheme 2009 -2012 • Trialing new techniques for improving the composition of material used for unsealed roads

  3. Outcomes • Results of the 3 trial sites monitored over 3 years • Protocol in the assessment process and decision making for material selection • Monitoring forms and process • Whole of life considerations

  4. Purpose • To better understand what makes a good material for unsealed roads (before it is used) • To acknowledge the large volumes of material used in unsealed road construction and to attempt to become smarter by introducing some science to compliment practical experience • Acknowledge some Councils Works Managers will not have years of local experience so setting up a framework and knowledge base to assist good decisions in material selection and treatment is critical for future success

  5. Trial Process • Pit Material testing against ARRB specifications • Assess options to improved material properties • Blending • Additives • Adapting works practices • Examine Whole of Life benefits of various treatments • Setup and monitor trial sites • Recording findings and reporting

  6. Adelaide Hills Councils • Dolomite and Monarto Material • Polycom in sections • Monarto, slightly finer grading ,less loose material and wear

  7. Goyder • Drews Pit – 5 sections • Polycom, Lime, Import material, bag lime in sections, untreated • Imported material to PM specification - higher loose material and windrow development • Lime not effective for low PI material • Polycom seemed to work with the fines to reduce windrow development and loose material.

  8. Loxton Waikerie • Lowbank Road • Dustcheck use to reduce dust • No observable dust reduction • Less rutting, windrow generation and loose material where additive used

  9. Pit Material Key Learning 1 Local Government need to recognise the difference between commercial products for base course, sub base course and material from pits for sealed roads to those attributes which contribute to a good wearing surface for unsealed roads. Unsealed Road Sealed Road

  10. Key Learnings

  11. Where we want to get to

  12. Key Learning Key Learning 2 Improve raw material before using additives Clear specification for grading and plasticity Pit operators need to blend stone, gravel and fines in proportion to develop acceptable material

  13. The Thirds Rule 10mm 0.5mm

  14. Blending at the Pit

  15. Use of testing information More Clayey More Gravel

  16. Key Learning Key Learning 3 Properties in the pit will be different on the road. Select the right equipment to suit the material Test post compaction from the road to determine compliance to grading and Plasticity

  17. When to Grid Roll/Rock bust

  18. When to crush and raw feed composition

  19. Blending on the Road Bed

  20. Additives Key Learning 4 For Drews Pit material at Goyder in hindsight the use of lime was inappropriate, however lime/fly ash may be an alternative in future trials. Key Learning 5 Polycom needs fines in the material to work. Further monitoring is recommended for each Council to determine if there is longer term benefits. After 2 years of monitoring there are positive indicators.

  21. Monitoring The monitoring methodology used was deliberately made simple to allow Councils field staff. In all cases the field record sheets were designed to allow for a systematic and consistent approach to record keeping The visual assessment observed Dust, Corrugation, Potholes and Loose Material on a course rating of LOW, MEDIUM and HIGH. The site measurement assessment consisted of: depth of rutting depth (mm) window height (depth) mm loose material (kg/0.5m2) Corrugations (depth mm, spacing (m))

  22. Monitoring

  23. Monitoring Key Learning 6 Dust assessment discernment is very difficult visually. The extent of humidity at time of assessment i.e. overcast, clear or recent rain needs to be recorded. Key Learning 7 While visual assessment of loose material may not be discernible, the measurement of windrow height and loose material are more indicative. Key Learning 8 Trial sites should be left without maintenance grading interventions if possible to develop a longer term trend of deterioration. Several Councils undertook grading operation during the trial period.

  24. Typical results

  25. WHOLE OF LIFE

  26. WHOLE OF LIFE

  27. Protocol for Unsealed Road Performance

  28. Protocol for Unsealed Road Performance

  29. Application to the wider local government Promotion Roads Conference and SALGSOA groups Get other Councils involved Kingston and Kangaroo Island are planning trials Support Tonkin/ARRB through Rod Ellis and Bob Andrews Tools Grading Assessment Tools Material performance Charts WOL Spreadsheets Field Trial monitoring forms Reporting Framework

  30. Upskilling

  31. Relating to Asset Management 47700 km of sheeted roads over 45 rural Councils $1.1 Billion Dollar asset in sheeted roads across the state $51 Million dollar annual re-sheeting across the state $1.1 Million dollar average re-sheeting /rural Council

  32. Road Hierarchies Asset Life linked to service standards and associated costs example

  33. Life Extension Impact across the state example

  34. Life extension Hypothetically how can 4 year increase life be achieved example based on percentages in previous slide

  35. Benefit to Asset Management An Average 4 year life increase across network can result in $175,000/annum/Council less re sheeting (18% saving)

  36. Shift from this

  37. To this

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