Reuse of RAP in asphalt pavements. RAP = Recycled Asphalt Pavement also called millings or grindings from:

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1 PASS Recycle/RAP Applications Definition RAP = Recycled Asphalt Pavement also called millings or grindings from: bump grinding of hot mix pavements millings from mill and fill operations large chunks of pavements from riprap operations Recycling Reuse of RAP in asphalt pavements 1

2 Benefits of Recycling Reuses and Conserves Non-renewable Natural Resources Preserves the Environment and Reduces Land Filling Conserves Energy/Reduces Truck Traffic Reduces User Delays During Construction Improves Pavement and Structural Section Physical Properties Reuse of Some of Our Best Aggregates, Which are Already In Place Cost Savings Over Traditional Methods (State Agencies 10 to 15%) (Industry and Local Agencies 25% to 50%) Western Emulsions Experience On-grade use of RAP materials Cold Central Plant Recycling (CCPR) Cold-In-Place Recycling (CIR) Yavapai County Experience RAP millings were used for base unbound and compacted with water, or Bound with SS, ERA s, CSS, CMS With mixed performance 2

3 PASS Recycle/RAP Performance PASS = asphalt, rejuvenating agent, specially developed polymer The low temperature flexibility of the PASS Recycle rejuvenating binder, combined with it s polymer network, enable PASS Recycle emulsion to bind RAP millings (grindings) together within a mix and to all compacted surfaces. PASS Recycle rejuvenates the aged, oxidized asphalt in the RAP but eliminates the slickness of rejuvenating oils such as ERA s Table Mixed PASS Recycle/RAP Yavapai County AZ Wexford Rd Lab Mix Data Table 1. PASS/RAP Mix % 1:1 Sample Ht. BSG Rice SG % Voids Corr. Flow PASS ID Stability 5 C Dry D Avg % Ret. Stability Soaked A B Avg E Dry F Avg Soaked G H Avg J Dry K Avg Soaked I L Avg

4 PASS Recycle/RAP Mix Yavapai County AZ -3/4 RAP, screened on 1 1/2 sieve, no new material added 2-3% pre-mix water added to mixing table PASS Recycle/RAP Mix Yavapai County AZ 6% PASS Recycle (1:1), or 3% PASS Recycle concentrate, was added to prewet the millings in the mix table PASS Recycle /RAP Stockpile Yavapai County AZ Table mix was stockpiled with bucket loader and stored for 1-4 days after mixing 4

5 PASS Recycle/RAP New Road Construction - Wexford Rd, Wilhoit AZ PASS Recycle/RAP mix was hauled by truck (approx. 25 miles) to Wilhoit where it was paver laid on a compacted RAP base (5-6 ) Burmed RAP millings for shoulders had been fogged with PASS Recycle PASS Recycle/RAP New Road Construction - Wexford Rd, Wilhoit AZ No problems with paver laying PASS Recycle/RAP New Road Construction - Wexford Rd, Wilhoit AZ 2 Steel wheel rollers 2 passes in vibratory mode, 2 passes static established as optimum rolling pattern. Rubber tire roller was used to iron out imperfections for several days following laydown. 5

6 PASS Recycle/RAP New Road Construction - Wexford Rd, Wilhoit AZ 1 Day after placement and compaction Wexford Rd open to traffic during construction New mat open to traffic 2-3 hours after rolling PASS Recycle/RAP New Road Construction - Wexford Rd, Wilhoit AZ 30 days after placement, no surface treatment No raveling Yavapai County fog sealed road with PASS QB after 6 weeks; chip sealed road after 4 months PASS Recycle/RAP New Road Construction - Ponderosa Park AZ 6

7 PASS Recycle/RAP New Road Construction - Ponderosa Park AZ PASS Recycle/RAP New Road Construction - Ponderosa Park AZ Uncompacted mat-4 Compacted mat-3 PASS Recycle/RAP New Road Construction Prescott Valley AZ Residential Street 7

8 Blade Laid RAP Millings with PASS Recycle Least Sophisticated Yavapai County Almost 10,000 tons of screened millings were pugmill mixed with PASS Recycle (1:1) at 7% and stockpiled for paver laydown over several weeks. PASS Recycle/RAP-CCPR 8

9 Yavapai County PASS Recycle/RAP RAP Feed Hoppers Conveyors from pugmill to stockpile Twin shaft pugmill Processed Millings 7% PASS Recycle (1:1) PASS Recycle/RAP Mix Laydown PASS Recycle/RAP Uncompacted Mat 9

10 PASS Recycle/RAP Rolling and Compaction PASS Recycle/RAP New Road Construction Prescott Valley AZ Residential Street Chip sealed 3 mos. After paving PASS Recycle for Cold-In-Place Recycling - CIR 10

11 PASS Recycle for Cold-In-Place Recycling SR892 - White Pines County, NV PASS Recycle CIR Mix Properties Core specimens were mixed at ambient temperature Core specimens were compacted at ambient temperature using a Gyratory Compactor (30 Gyrations) Core specimens were cured at 60ºC for 48 hours Preconditioned core specimens were vacuum saturated (55-75%), subjected to one freeze thaw cycle, soaked at 25ºC for 23 hours and 1 hour at 40ºC Emulsion, w% of PASS Recycle Density, lbs/ft Maximum Theoretical Specific Gravity Dry Specimen Bulk Specific Gravity Air Voids, % Stability, 40ºC, Inch-Pounds Preconditioned Specimens Bulk Specific Gravity Air Voids, % Vacuum Saturation, % Retained Stability, 40ºC, Inch-Pounds Retained Strength, % PASS Recycle - CIR Existing Pavement multiple chip seals over cold mix. Asphalt rich. 11

12 PASS Recycle - CIR CIR addresses cracking PASS Recycle contains both a rejuvenator and a polymer modifier to ensure excellent coating, adhesion and long term performance. PASS Recycle - CIR 1.5% PASS Recycle Milled out 3, replaced 2.5 Widened and recrowned road PASS Recycle - CIR 100% Coating of RAP millings 12

13 PASS Recycle - CIR $$$ PASS Recycle/RAP - 40% to 60% of the cost of hotmix. SR892 CIR even with asphalt price spike, cost was 90% of the contract bid price of CMS-2S with lime, using a solventless system. Both the paving season and pavement service life were extended using PASS Recycle. NDOT has specified 3 projects for spring 2006 Tips for Successful Recycling and Reclamation Analyze Existing Structure & Conditions Understand Causes for Distress Analyze Profile of Road Consider any Drainage or Base Problems Select Best Materials & Methods Use Engineered Approach 13

14 Questions?? 14