Nebraska Projects - RMACESNebraska Projects Addressing the Top Ten RAP Issues Robert C. Rea, P.E ... that limit RAP • Target 3% Air Voids at 7-65-100 Gyrations • VMA is an issue

Nebraska ProjectsAddressing the Top Ten RAP Issues

Robert C. Rea, P.EAssistant Materials and Research Engineer

Nebraska Department of RoadsFebruary 22, 2012

Thursday, April 19, 2012

TOP TEN REASONS RAP IS NOT OPTIMIZED



1. Owner/Specifier limits use of RAP or says ‘I want the new stuff, not the used stuff ’




2. Stigma of lesser quality, need to Engineer




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’4. Design not optimizing mill and fill strategies or ‘Road Mining’




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’4. Design not optimizing mill and fill strategies or ‘Road Mining’5. RAP not made available or charges too much for it




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’4. Design not optimizing mill and fill strategies or ‘Road Mining’5. RAP not made available or charges too much for it6. Required binder bumps/reductions when higher amounts are used




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’4. Design not optimizing mill and fill strategies or ‘Road Mining’5. RAP not made available or charges too much for it6. Required binder bumps/reductions when higher amounts are used7. Restrictive in the specification, i.e. dust/asphalt maximum




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’4. Design not optimizing mill and fill strategies or ‘Road Mining’5. RAP not made available or charges too much for it6. Required binder bumps/reductions when higher amounts are used7. Restrictive in the specification, i.e. dust/asphalt maximum8. Limits RAP #200 amounts and rejects the RAP




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’4. Design not optimizing mill and fill strategies or ‘Road Mining’5. RAP not made available or charges too much for it6. Required binder bumps/reductions when higher amounts are used7. Restrictive in the specification, i.e. dust/asphalt maximum8. Limits RAP #200 amounts and rejects the RAP9. Restrictive Voids and VMA and other properties that limit RAP




2. Stigma of lesser quality, need to Engineer 3. Plant says ‘Can’t Run it’4. Design not optimizing mill and fill strategies or ‘Road Mining’5. RAP not made available or charges too much for it6. Required binder bumps/reductions when higher amounts are used7. Restrictive in the specification, i.e. dust/asphalt maximum8. Limits RAP #200 amounts and rejects the RAP9. Restrictive Voids and VMA and other properties that limit RAP10. Too much hassle, one more thing to Manage and Design for










10. Too much hassle, one more thing to manage and design for

• True• Must manage equally as any different aggregate• Its affects to the mix properties are critical as it is 40 – 50 %



• True• Must manage equally as any different aggregate• Its affects to the mix properties are critical as it is 40 – 50 %• Stockpile and manage different RAP in different piles



• True• Must manage equally as any different aggregate• Its affects to the mix properties are critical as it is 40 – 50 %• Stockpile and manage different RAP in different piles• Gradations and Binder contents need to be tested



• True• Must manage equally as any different aggregate• Its affects to the mix properties are critical as it is 40 – 50 %• Stockpile and manage different RAP in different piles• Gradations and Binder contents need to be tested• Plant and Loader personnel are key to the Management of

the materials































9. Restrictive Voids and VMA and other properties that limit RAP



• Target 3% Air Voids at 7-65-100 Gyrations• VMA is an issue when using ignition oven Gsb









Virgin

RAP Ignition Oven

Burn off asphalt

RAP Agg.

Virgin Agg.











8. Limits RAP #200 amounts and rejects the RAP



• Some Agencies wanted to do this



• Some Agencies wanted to do this• Test the final Product and make the QC/QA do the work• Many plants meter the dust and even drop some if needed



















7. Restrictive in the specification, i.e. dust/asphalt maximum


7. Restrictive in the specification, i.e. dust/asphalt maximum

• Use Newest Dust/Binder Recommendations of 0.6 to 1.6, used to be 0.6 to 1.2

• Another increase with the use of 1% Lime


7. Restrictive in the specification, i.e. dust/asphalt


7. Restrictive in the specification, i.e. dust/asphalt

d/a 0.6 to 1.6, increased to 0.7 to 1.7 with 1% Lime










6. Required binder bumps/reductions when higher amounts are used

• Used to Require this• Costs about $ 50 more per liquid ton• Again puts a restriction when perfectly good mix can use

more RAP


6. Required binder bumps/reductions when higher amounts are used

• Used to Require this• Costs about $ 50 more per liquid ton• Again puts a restriction when perfectly good mix can use

more RAP• This is always covered when using PG XX-34 Grades

across the board










5. RAP not made available or charges too much for it

• YES, RAP IS WORTH A LOT !• Some wanted way too much, and priced out its use



• YES, RAP IS WORTH A LOT !• Some wanted way too much, and priced out its use• Don’t forget, hauling, stockpiling, handling etc.



• YES, RAP IS WORTH A LOT !• Some wanted way too much, and priced out its use• Don’t forget, hauling, stockpiling, handling etc.• It’s full potential is realized when made available ;



• YES, RAP IS WORTH A LOT !• Some wanted way too much, and priced out its use• Don’t forget, hauling, stockpiling, handling etc.• It’s full potential is realized when made available ;• From the project



• YES, RAP IS WORTH A LOT !• Some wanted way too much, and priced out its use• Don’t forget, hauling, stockpiling, handling etc.• It’s full potential is realized when made available ;• From the project• Stockpiles stated in the Special Provisions• The unit prices are typically 20 to 25% lower










4. Design not optimizing mill and fill strategies or ‘Road Mining’

• Generate it from the project whenever possible• Milling provides not only the valuable RAP ;• It is on site, minimal haul



• Generate it from the project whenever possible• Milling provides not only the valuable RAP ;• It is on site, minimal haul• It can be tested and properties evaluated prior too



• Generate it from the project whenever possible• Milling provides not only the valuable RAP ;• It is on site, minimal haul• It can be tested and properties evaluated prior too• Provides better texture for overlay to bond



• Generate it from the project whenever possible• Milling provides not only the valuable RAP ;• It is on site, minimal haul• It can be tested and properties evaluated prior too• Provides better texture for overlay to bond• Removes surface irregularities• Can correct the profile



• Removes unwanted hot pour from surface• Provides fresh pulverized millings• Generally makes millings more uniform



• Removes unwanted hot pour from surface• Provides fresh pulverized millings• Generally makes millings more uniform• Reduces grade raise, for any guardrail, curb and gutter,

matching into structures, elevation issues etc.






ROAD MINING !

Existing Original Base Pavement

Existing Asphalt

Subgrade


ROAD MINING !


Subgrade


ROAD MINING !


Subgrade


ROAD MINING !


Subgrade

Every inch of millings of existing pavement, 24 foot wide, contains

$30,000 to $40,000 of Oil and Aggregate










3. Plant says ‘Can’t Run it’

• Need RAP feed system/collar• Grizzly and screening deck• Baghouse and plant need to be checked and see its

capabilities




capabilities• Something new to some, unknowns




capabilities• Something new to some, unknowns • Something different• All of our plants typically run between 40 & 50%



























• Low temperature binder grades, such as XX-34• Soft base to rejuvenate the aged and oxidized binders• Use Polymer modified as much as you can, polymer loading



• Low temperature binder grades, such as XX-34• Soft base to rejuvenate the aged and oxidized binders• Use Polymer modified as much as you can, polymer loading• Much better compaction, not beating the heck out of the mat

and not fracturing aggregate• More dense



• No interconnected voids• Better Joint Density and Compaction• More resistant to water damage and aging due to such a

dense matrix



• No interconnected voids• Better Joint Density and Compaction• More resistant to water damage and aging due to such a

dense matrix• Compaction at laydown is much better, even with the

polymer modified• SPR is the industries favorite mix to lay


VirginRAP

Polymer

2.25%

VirginRAP

Polymer

2.25%1.25%

VirginRAP

Polymer

2.25%1.25%2.25%1.25%2.25%1.25%2.25% 2.50%


90%

10%Conventional (PG 64-‐28)

VirginRAP

Polymer

2.25%

VirginRAP

Polymer

2.25%1.25%

VirginRAP

Polymer

2.25%1.25%2.25%1.25%2.25%1.25%2.25% 2.50%


90%


VirginRAP

Polymer

2.25%

50%

50%

High Recycle Conventional (PG 64-‐28)

VirginRAP

Polymer

2.25%1.25%

VirginRAP

Polymer

2.25%1.25%2.25%1.25%2.25%1.25%2.25% 2.50%


90%


VirginRAP

Polymer

2.25%

50%

50%

High Recycle Conventional (PG 64-‐28)

VirginRAP

Polymer

2.25%1.25%

50%

High Recycle Polymer Loading (PG 64-‐34)

VirginRAP

Polymer

2.25%1.25%2.25%1.25%2.25%1.25%2.25% 2.50%










1. Owner/Specifyer limits use of RAP or says ‘I want the new stuff, not the used stuff ’



Whether it is made from…….



New Aluminum




New Aluminum Recycled Aluminum




New Aluminum Recycled Aluminum

You can’t taste the difference




Thank You!


Documents

Nebraska Projects - RMACESNebraska Projects Addressing the Top Ten RAP Issues Robert C. Rea, P.E ... that limit RAP • Target 3% Air Voids at 7-65-100 Gyrations • VMA is an issue