Strategies for Smooth Pavements
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Examples of how new technologies and strategies are assisting contractors in building smoother pavements for the demanding public. Presented by Don Matthews, PRS, at the 2017 CalAPA Fall Asphalt Pavement Conference in Sacramento.
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Strategies for Smooth Pavements
- 1. Strategies for Smooth Pavements Don Matthews, PE Pavement Recycling Systems, Inc. Fall Asphalt Pavement Conference and Equipment Expo October 26, 2017
- 2. Antonymy of the Smoothness of a Roadway Construction Practices DesignStrategy Poor Best AppropriatePoor Really Bad Bad So So Great Hitting Here is What All of Us Owe the Tax Payers of California
- 3. Goals for Today’s Presentation Review Smoothness Terminology Review Issues on Projects for Smoothness Brief Overview of 2D and 3D Technology Come to the Only Logical Solution to Obtain Smoothness
- 4. Disclaimer This Presentation is for Educational Purposes Only The Goal is to Improve All Aspects of Smoothness Its Should Not Be Used in the Preparation or Defense of Any Claim or Dispute Without The Written Consent of the Author and CalAPA
- 5. Terminology Overview - International Roughness Index (IRI) IRI is a smoothness value obtained by processing a profile through the ProVAL computer program (algorithm) It is based on a golden car (representing 70% of vehicles) It analyzes roughness inputs in a single wheel path
- 6. ProVAL ©Copyright the U. of Michigan
- 7. Areas of Localized Roughness (ALR) ALRs are individual roughness locations (caused by bumps or dips) where the IRI of the existing surface exceeds a specified IRI level. It is expressed by peak IRI value
- 8. 528’ One Wheel Path Only Mean Roughness Index (MRI) MRI is the average of the IRIs from the left and right wheel paths over a 0.1 mile (528) section of a lane
- 9. Definitions –MRI 0.1 mile 0.1 mile ETW RWP = Right Wheel Path LWP = Left Wheel Path ETW Direction of Travel RWP LWP Ave. IRI = 58 in/mi Ave. IRI = 62 in/mi Direction of Travel MRI = 60 in/mi Ave. IRI = 64 in/mi Ave. IRI = 60 in/mi MRI = 62 in/mi
- 10. Terminology - This is NOT a Grinder This is a: • Cold Planer • Mill • Cold Mill It typically has conical carbide tipped cutting tools (teeth) Therefore prohibited by specification for final surfaces It can have diamond tipped tools. A few have flat teeth Its head height can change continuously based on a referencing system or automatic machine guidance
- 11. Micro Mill vs Standard Cold Planer Micro Milled Surface Standard Milled Surface Micro Milling Drum Standard Milling Drum Smooth surfaces can be obtained with a standard cold planer A micro mill finer tool pattern provides: • Less raveling of exposed aggregate from traffic • Smaller ridges and valleys for less cover needed • Better surface control for smaller removals • Less surface impact due to teeth wear
- 12. In All Cold Planing Best Practices Must Be Followed: Transitions into and out of cuts must be smooth The milled surface must be cleaned well The drum must not be stopped while still in the cut The mill’s mechanical systems must be maintained The cutting tools and blocks must be maintained and/or replaced as needed
- 13. Appropriate Continuous Speeds Must be Maintained Do not out run the pattern – The texture changes as speed increases. Don’t overrun averaging system It may not be about production!!
- 14. Terminology - This is a Diamond Grinder Gives a smooth finish surface. Good for final surface corrections Is a “rigid” frame planer equipped with diamond tipped blades Head height is set and fixed to the position of the front and rear wheels
- 15. Diamond Grinding or Cold Planing Corrections Can Only Do So Much Can only go deeper or wider Can’t fix a pavement or subgrade
- 16. WORKING CRACKS – Respond Dynamically to Vehicles, Including Inertial Profiler Working – Not correctible by grinding or cold planing Non Working – Likely correctible by grinding or cold planing
- 17. Definitions of Opportunities and Referencing Existing Surface (200 MRI) Opportunity 1 (Improvement to 90 MRI) Opportunity 2 (Improvement to 60 MRI) Must Be Variable Depth
- 18. Existing Surface MRI (in/mi) New Surface MRI (in/mi) 300 120 200 90 150 75 120 65 90 60 60 45 *Based Upon One Smoothness Opportunity Using Best Paving Practices Reasonable Expected Improvement Values For Each Smoothness Opportunity* So if you want to a achieve a smoothness level but the existing is too rough for the design strategy, you need to add a smoothness opportunity
- 19. Existing Pavement Surface Aggregate Base/Subgrade Cold Planing (Mill and Fill) “Smoothness Opportunities” in HMA HMA Overlay Existing Pavement Surface Aggregate Base/Subgrade Pre-pave Corrections Filled HMA HMA Overlay Existing Pavement Surface Aggregate Base/Subgrade Cold In-place Recycling With Overlay CIR
- 20. Pre-Pave Corrections (Pre-Pave Grinding) Existing Asphalt Surface Prior to Overlay or Pavement Preservation Seal Existing Pavement Surface Aggregate Base/Subgrade Pre-Pave Correction Should be a Smoothness Opportunity HMA Overlay But is it?
- 21. +/- Existing Pavement Surface Entire roadway corrected 100% to no ALR > than 180 in/mi Pre Pave Correction With Overlay Example Requires 0.15’ HMA overlay
- 22. +/- Existing Pavement SurfaceHMA Overlay Referencing system not using pre pave corrections – Using rougher shoulder and not corrected pavement Pre pave corrections provide little opportunity to improve to smoothness Pre Pave Correction With Overlay Ex. Cont.
- 23. May Need to Set Up Referencing System Differently
- 24. +/- Existing Pavement SurfaceHMA Overlay Variable Width Paving Variable width paving causes a change to the head of material against the screed Difficult to produce a level, smooth pavement surface if the head of material fluctuates against the screed
- 25. Constant Head of Material Half auger level Constant resistance Constant depth Increased Head of Material Increased height Resistance increased Depth increases Decreased Head of Material Decreased height Resistance decreased Depth decreases Head of Material in Front of the Screed Screed will change its height (relative position) due to the resistance from the head of material in the auger chamber
- 26. +/- Existing Pavement Surface Cold Planing as an Opportunity Is Cold Planing a Smoothness Opportunity? Maybe
- 27. Variable Depth Cold Planing Must be Used Constant depth will transfer the roughness to the bottom of the cold planed surface Good averaging systems should be used when cold planing the existing surface Variable Depth 2D Averaging - Sufficient for the Majority of Applications if an Effective Correction Strategy is Designed
- 28. For 2D Averaging, Referencing Is Important! Here? Where Do We Run the Reference Averaging System While Cold Planing? Here? Need to Find Smoothest Referencing Surface Available
- 29. +/- Existing Pavement Surface Cold Planing Could be an Opportunity But not if the paver does not use it for 2D referencing Paver 2D referencing needs to be on cold planed surface if smoother Must also consider matching constraints
- 30. Matching Constraints and Challenges with Smoothness Existing Pavement Surface Aggregate Base/Subgrade Filled HMA How do you run a matching shoe on a 120 in/mi MRI shoulder? But pave a 60 in/mi MRI just 3 feet over? Not likely Need to allow variable depth paving with a good referencing surface
- 31. Pre Milling Post Milling MRI (in/mi) MRI (in/mi) Change in MRI % Change 127 96 31.2 25% 120 98 21.6 18% 74 77 -2.4 -3% 95 94 1.5 2% 83 145 -61.9 -75% 96 101 -4.8 -5% 77 99 -22.7 -29% 88 114 -26.7 -31% 80 128 -48.1 -60% 78 118 -40.0 -52% 86 88 -2.1 -2% 64 112 -47.7 -74% 65 104 -39.0 -60% 90 123 -33.5 -37% 63 91 -27.8 -44% 72 97 -25.1 -35% 101 96 5.0 5% 79 110 -30.4 -38% 61 140 -78.8 -129% 61 113 -51.5 -84% 70 91 -21.2 -30% 71 105 -33.3 -47% 123 130 -7.0 -6% 72 125 -53.0 -74% 81 75 5.3 7% 77 107 -30.3 -40% 98 106 -8.2 -8% Highway Project 4” Mill Depth Made Worse in Many Cases In Some Instances Cold Planing May Not Improve Smoothness
- 32. If delamination occurs, the cut depth must be increased Paving over a delaminated surface can result in differential compaction A delaminated surface will also provide a rough reference line for the paver Delamination
- 33. For 2D, Referencing Has a Major Impact on Smoothness The longer and smoother the reference, the smoother the pavement . And Please! – Once a good reference line is set, trust the equipment! Manual adjustment = ALR Variable depth thin cut ski runs for a cold planer or paver can be made if necessary
- 34. Example Project of True Partnering Fog Line Existing Pavement Surface Cold Plane Originally Proposed Strategy No Place for Referencing for Cold Planer or Paver Centerline Variable Width Uneven Shoulder Filled HMA Uneven Fills
- 35. Example Project (Cont.) Fog Line Existing Pavement Surface Cold Plane Partnered Constructed Strategy Cut Ski Run for Paver Referencing Centerline Shoulder Filled Separately Filled HMA Even Width Fill
- 36. Existing Pavement Surface Aggregate Base/Subgrade Cold In-place Recycling (CIR) With Overlay HMA Overlay Smoothness Opportunity? CIR Smoothness Opportunity?
- 37. +/- Existing Pavement SurfaceCIR Contractor Spent Weeks of Corrections in Wheel Path Old Specification - CIR Required 75 in/mi MRI But Paver did Not use Corrected Surface for 2D referencing HMA Overlay Guesss What?
- 38. CIR as a Smoothness Opportunity? CIR tends to make a smooth surface rougher and rough surface smoother CIR smoothness is influenced by a variety of things: • Many different varying previous overlays • Multiple maintenance surface seals • Variations in distresses • Environmental conditions • Air temperature • Pavement temperature
- 39. Its More About Using Best Paving Practices Regardless of the existing roadway’s roughness, using best practices can result in smoothness of the CIR of about 90 in/mi MRI (New Spec) A 60 in/mi MRI should then be attainable on the HMA overlay
- 40. CIR Section with Test Project of one mile at end of project NB lane No ProVAL SAM analysis Micro milled with averaging system – Took 4.5 hours Corrected average MRI of 95.6 in/mi to 70.7 in/mi Corrected 7 areas of ALR over 180 in/mi to no areas of ALR over 180 in/mi SB lane ProVAL SAM system followed completely using a diamond grinder – Stopped after 8 hours Corrected Average MRI of 93.9 in/mi to 84.7 in/mi Tried to correct 3 areas of ALR over 180 in/mi but still had 3 areas of ALR over 180 in/mi when stopped Correct CIR With a Micro Mill and Not Diamond Grinder
- 41. Consistency - Head of Material on Screed Besides Referencing Consistency = Best Paving Practices Consistency - Paving Speed Consistency - Mix Temperature
- 42. Check Your Crew Against a Reasonable Expectation Metric • Mark Collection Start of Your IP Run Before Paving • Determine MRI of the Existing Before Paving • Determine MRI After Paving • Compare Each 0.1 mile Section To the Below:
- 43. If You Are Not Meeting Expectations CalAPA’s ½ Day Training Class PAVEMENT SMOOTHNESS ESSENTIALS -- NEW SPECIFICATIONS, TECHNOLOGY & BEST PRACTICES Consider Training
- 44. 3D Control - Total Station Machine Control The Preferred Choice When Required to Cut to Specific Grades at Specific Elevations
- 45. Oakland Airport With 6 Automatic Machined Controlled Mills Working Simultaneously
- 46. Hit Multiple Precise Grade Changes
- 47. But 6 Mills Require
- 48. Approx. 600’ Approx. 600’ Approx. 600’Approx. 600’ Limited to 1,200’ Spacing and Leap Frogging of Guns
- 49. Traffic control is typically required to take existing surface readings to build model With one set of existing surface readings models can be made for control of the cold planer and multiple paving lifts Total Station Modeling
- 50. An Alternative 3D Solution for Rehab Projects Uses GPS to Position Horizontally with Scanned Surface for Vertical Road Surface Can use LiDAR Relative Surface Scanning
- 51. Can also use laser Relative Surface Scanning
- 52. Machine Control is Based Upon Relative Depth and Not Elevation Approx. 2 Miles No Need to Leap Frog Base Station Approx. 2 Miles Traffic control is not required to take readings to build model Model cannot be used for multiple lifts. A new model is required for paving or if surface has changed at all Subject to GPS quality issues
- 53. Conclusion – How To Get A Smooth Road Agency + Contractor - Use Best Construction Practices Agency - Incorporate A Design Strategy Appropriate for Existing Roadway Conditions Contractor Together The Only Way to Get The Best Roadways!
Hinweis der Redaktion
- No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride. Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer. Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents. Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
- No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride. Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer. Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents. Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
- No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride. Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer. Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents. Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
- No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride. Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer. Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents. Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
- No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride. Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer. Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents. Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
- No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride. Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer. Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents. Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.
- No matter how well a pavement is designed and built, no matter how long that pavement lasts, the users of the roadway will call it good or bad primarily based on the smoothness (or comfortability) of the ride. Numerous studies by the Federal Highway Administration, National Cooperative Highway Research Program (NCHRP), and National Asphalt Pavement Association (NAPA) have looked at the affect of smoothness on pavement life. There studies have found a common thread: Pavement built smoother tend to last longer. One reason as to why they last longer could be attributed to the effect of dynamic loading. Rougher pavements result in more dynamic loading, subjecting pavements to much heavier loads than they were designed for. Thus, wearing them out faster. There is evidence from limited studies of smoothness progression over time shows that pavements built smoother will stay smoother longer. There are a lot of design and construction factors that influence smoothness; but when designed and constructed properly, smoother roads tend to stay smoother longer. Rough roads can result in a loss of vehicle control, a reduction in a person’s ability to perform motor tasks, driver fatigue, and an increased frequency of lost load accidents. Smoother roads help save both the user and owner-agency money. Studies suggest that pavements built smoother initially, require less maintenance over the life of the pavement. Additionally studies have shown that smoother pavements decrease both fuel consumption and vehicle maintenance for users.