Sustainable Pavement Preservation Strategies to extend the life of Local Roads

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1 Sustainable Pavement Preservation Strategies to extend the life of Local Roads Ross Ioakim, Sector Lead Local Government and Airports 1 Presentation Outline Challenges facing Councils Issues impacting local roads Pavement Preservation Strategies Treatment Life Cycle comparison Summary 1

2 Challenges facing Councils Ageing infrastructure creating backlog Constrained budgets, recurrent and capital works Pressure to maintain/increase service standards Climate change and carbon reduction Local Roads Local and low volume roads account for approx 80% of the total length of sealed roads in Australia Local communities in metropolitan and regional centres expect smoother roads following the continued growth of new subdivisions surfaced with asphalt since the late 1970 s Ageing local road networks are placing an ongoing strain on Councils budgets and a sustainable Road Asset Management strategy is required to maximise pavement life on constrained budgets 2

3 Impact of environmental factors on local roads A sustainable pavement preservation strategy is required to extend the pavement life of local roads from the effects of weathering due to environmental factors Typical condition of asphalt surface, age 15+ years Surface ravelling evident from 5 to 6 years Pavement Life Cycle with treatment strategies Pavement condition Good Fair Poor Very poor Rehabilitation Preservation Pavement Life 3

4 Local road surface treatment options Asphalt overlays < 40mm Microsurfacing Spray seals Rejuvenation - Aspen Surface Preservation Liquid Road & MasterSeal Designed to preserve and protect surfacing and prolong pavement life Do not address defects resulting from structurally deficient pavements Comparison of surface treatment options Treatment Price Range Life Asphalt $ $20.00/m yrs Microsurfacing $ $10.00/m yrs Spray seal $ $7.00/m yrs Liquid Road $ $4.00/m yrs Aspen - Rejuvenation < $2.00/m yrs 4

5 Environmental and Social benefits Microsurfacing, Liquid Road and Aspen - engineered treatments utilising emulsion technologies Cold applied No fuming Low odour No VOC Reduced Carbon footprint Provide safer working environment Pavement Life Cycle with treatment strategies Early Intervention treatments applied every 4-7 yrs Pavement condition Good Fair Poor Very poor Preservation Rehabilitation Pavement Life 5

6 Early intervention treatment options Rejuvenation Surface preservation MasterSeal PM Early intervention treatment options Engineered to extend surface life of local roads by: Sealing the surface against the intrusion of air and water Preserving and protecting the binder that has hardened through oxidation and weathering Eliminating the loss of aggregate from seals and fines from asphalt and Microsurfacing Sealing fine cracking and replacing fines, lost through weathering and oxidation Do not address structural issues, they prevent them 6

7 Early adopters of rejuvenation treatments NSW Tweed Shire Cncl Newcastle Cncl Penrith Cncl QLD Thuringowa now part of Townsville Cncl Gold Coast Cncl SA Mitcham Cncl Prospect Cncl Optimum time to apply: Surface Age < 8 years Raveling initial onset of loss of fines Cracking none to minor Rejuvenation demonstrated long term performance Tweed Shire Council Banora Point Pavements constructed from late 1970 s to early 1980 s Initial treatment by YR8, then every 6 to 8 years Several rejuvenation treatments to date Current surface age >35 years Total maintenance costs to date < $10.00/m 2 7

8 8/1/2014 Rejuvenation demonstrated long term performance Newcastle Council adjoining roads, Wallsend Claymore Cl, Initially surfaced in 1995 No treatments Boambee Cl, Surfaced in 1992, Three treatments to date Rejuvenation performance of treated vs untreated Townsville City Council Waterview Dr Bushland Beach Thuringowa Council, Aspen trigger was age = 8 years Aspen treatment circa 2008 due for next treatment Treated Untreated Untreated Treated 8

9 Surface Preservation treatment Engineered product comprising polymers, fibres and fine aggregate that restores texture, surface matrix and seals cracks < 2-3 mm Optimum time to apply; Surface Age > 12 years Asphalt - moderate to severe ravelling Seals - first sign of stone loss Pavement profile good Minor environmental cracking Application rate 1.0 to 1.5 l/m 2 Liquid Road before and after treatment Spray Seal and AC surface 9

10 8/1/2014 Liquid Road after 5 years Local Road, Blacktown Cncl LHS not treated, RHS after 5 years traffic has worn Liquid Road from top of aggregate but voids still filled Liquid Road treated vs untreated Treated Untreated Sharp St, Geelong Liquid Road applied Feb % reduction in permeability 10

11 Determine application rate and treatment option Sand Patch tests to determine surface texture and optimum application rate Process and Application Inspection and testing of pavements for suitability Pre treatment including minor pavement repair and cracksealing (note cracksealing can be applied post treatment) Traffic management including resident notification Highly mobile crew plus traffic control Weather and temperature dependant - from end September to April/May (sth of Brisbane) and from May to Sept (nth of Brisbane) Preferred hours of spraying from 9.00am to 5.00pm 11

12 8/1/2014 Microsurfacing surface preservation treatment Salisbury Council SA Microsurfacing surface preservation treatment An ambient temp, paver applied bituminous surfacing that is manufactured onsite at the point of application comprising of; dense graded aggregate blends, max size either 5mm or 7mm polymer modified bitumen emulsion 12

13 Microsurfacing SFT Suspended Fibre Technology EACH INGREDIENT HELD IN SEPARATE MIXING IN PUG COMPARTMENT ADDED TO PUG MILL IN CALIBRATED MILL RATIOS ACCORDING TO MIX DESIGN MIXED MATERIAL LAID FROM PAVING BOX AGGREGATE FILLER EMULSION WATER DIRECTION OF TRAVEL PUG MILL PAVING BOX MIXTURE BROWN/ HOMOGENOUS MIXTURE BLACK Mixing Time <1 min Workable Life 2-3 min Curing Time Traffic in Maximum One Hour Microsurfacing SFT Suspended Fibre Technology Microsurfacing SFT has been developed to provide a thin surfacing with enhanced properties flexibility modulus 13

14 Microsurfacing applications Local roads Shared Paths Major Highways and Freeways Airfields Concrete pavements Microsurfacing for local roads No loss of curb reveal or impact on existing drainage Provides a smooth safer surface Durable impervious surface Excellent skid resistance Restores pavement profile and shape Aesthetically similar to an asphalt finish 14

15 Microsurfacing SFT for shape correction & rut filling Specialised paving screed application Effective method for correcting pavement shape Provides minimal tie in points to existing pavement and no interference with existing drainage Enables only ruts to be filled Edges do not fret and ravel Rut filling with seal Rut filling with asphalt Microsurfacing SFT for shape correction & rut filling Utilised extensively by state road authorities throughout Australia to improve pavement shape and cross fall Benefit pavement life extension, improved ride resulting in less accidents 15

16 Microsurfacing SFT for stripped seals Fills voids and provides uniform surface texture Prevent further aggregate loss Minimal risk of bleeding or incorrect binder application Protects and extends existing pavement life Life Cycle cost comparisons to achieve > 35 years life of asphalt roads Rejuvenation - initial Aspen treatment at YR8 with subsequent treatments every 6 years = $12.00/m 2 Preservation initial Liquid Road treatment at YR12 with subsequent treatments every 6 years = $12.50/m 2 Spray Seal initial treatment at YR12 followed by rejuvenation treatment every 6 years = $14.00/m 2 Microsurfacing initial treatment at YR12 followed by rejuvenation treatment ever 6 years = $16.00/m 2 Asphalt - edge plane & 25mm AC resheet at YR20 and YR40 = $40.00/m 2 16

17 Sustainable Pavement Preservation Strategies Collaborative relationships with Council and PMS Consultant provides opportunities to; Develop and implement effective Pavement Preservation strategies to maximise asset life at lowest life cycle cost Apply timely Pavement Preservation treatments to maintain surfacing in good condition and extend life > 35 years Maintain a greater % of road network annually 17