block 6 sp 14
TRANSCRIPT
![Page 1: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/1.jpg)
Asphalt Binder Modified Binders 1
Modified Asphalt Binders
Senior/GraduateHMA Course
![Page 2: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/2.jpg)
Asphalt Binder Modified Binders 2
Why are Modifiers Used?• Mitigate both traffic- and environmentally
induced HMA pavement distresses– Rutting resistance
•Stiffer asphalt binders at warm temps– Thermal cracking
•Inhibit crack propagation– Internal elastic network (polymers)–Crack pinning (solid particles)
![Page 3: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/3.jpg)
Asphalt Binder Modified Binders 3
Types of Modifiers• Polymers
– Plastomers– Elastomers
• Fillers– Gilsonite– Mineral fillers– Misc.
![Page 4: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/4.jpg)
Asphalt Binder Modified Binders 4
Polymers• Plastomers
– Quick early strength but with little ability to strain without brittle failure
– Any strain tends to be permanent•Little elastic behavior
![Page 5: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/5.jpg)
Asphalt Binder Modified Binders 5
Plastomer Product Examples
Trade Manufacturer Type ChemistryNameNovophalt Novophalt Copolymer LDPE
Elvax DuPont Copolymer EVA
Polybuilt Exxon Copolymer EMA or EVA
Starflex Carraux Copolymer EVA
![Page 6: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/6.jpg)
Asphalt Binder Modified Binders 6
Polymers• Elastomer
– Resist permanent deformation by an ability to stretch and recover shape once load is removed
– Only contribute to tensile strength when stretched
![Page 7: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/7.jpg)
Asphalt Binder Modified Binders 7
Elastomer Examples
• Natural Rubber• Synthetic Rubber
– Styrene-Butadiene Rubber (SBR)•Random block
• Thermoplastic Rubbers– Styrene-Butadiene-Styrene (SBS)
•Triblock copolymer that form network
![Page 8: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/8.jpg)
Asphalt Binder Modified Binders 8
Elastomer Product Examples
Trade Manufacturer Type ChemistryNameDownright DOW Random SBR
Copolymer
Kraton Shell Block SBSCopolymer
Styrelf Koch Block BlendedCopolymer
Vector Exxon Block SBSCopolymer
![Page 9: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/9.jpg)
Asphalt Binder Modified Binders 9
Common Polymer Terms
Straight Chain or Linear
Radial
Polymer with Branches
Crosslinked
![Page 10: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/10.jpg)
Asphalt Binder Modified Binders 10
SBS Polymers in Asphalt Binders
Step 1
Step 2
Step 3
Polymer Polymer in hot AC
Polymer in cool AC
StyreneButadiene
![Page 11: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/11.jpg)
Asphalt Binder Modified Binders 11
Traditional Testing for Modified Asphalt Binders
• Vacuum viscosity– Asphalt Institute tubes
• Ductility– Elastic recovery
• Softening Point– Increases with polymer concentration
• Toughness and Tenacity• Separation
![Page 12: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/12.jpg)
Asphalt Binder Modified Binders 12
TEM Microphotographs
2% Linear SBS 4% Linear SBS
White area = Asphalt Binder and Black area = polymer
500 nm 500 nm
![Page 13: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/13.jpg)
Asphalt Binder Modified Binders 13
TEM Microphotographs
6% Linear SBS 10% Linear SBS
500 nm1 m
White area = Asphalt and Black area = polymer
![Page 14: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/14.jpg)
Asphalt Binder Modified Binders 14
TEM MicrophotographsWhite area = Asphalt Binder and Black area = polymer
4% Radial SBS
![Page 15: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/15.jpg)
Asphalt Binder Modified Binders 15
NCHRP Report 459
Characterization of Modified Asphalt Binders in Superpave Mix Design
![Page 16: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/16.jpg)
Asphalt Binder Modified Binders 16
Topics Covered
• Storage stability of modified asphalt binders• Shear-rate dependency of viscosity• Strain dependency of rheological response• Effect of mechanical working• Loading-rate dependency and time-temp
equivalency
![Page 17: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/17.jpg)
Asphalt Binder Modified Binders 17
Modified Asphalt Binders• Simple asphalt binders
– Do not violate assumptions of Superpave rheological tests
• Complex asphalt binders– Behavior (characteristics) violate one
or more assumptions
![Page 18: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/18.jpg)
Asphalt Binder Modified Binders 18
Simple Asphalt Binders
• <2% by vol of additives retained on No. 200 sieve– PAT with toluene
• Stable for 2 or more days at mix/compact temps– LAST
• Reasonably linear over range of stress and strain• Insensitive to cyclic damage during testing
![Page 19: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/19.jpg)
Asphalt Binder Modified Binders 19
Particulate Additive Test (PAT)
![Page 20: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/20.jpg)
Asphalt Binder Modified Binders 20
Laboratory Asphalt Stability Test(LAST)
![Page 21: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/21.jpg)
Asphalt Binder Modified Binders 21
Other Topics• Researchers addressed
– Effect of traffic volume– New procedures for low temperature
cracking prediction models
![Page 22: Block 6 SP 14](https://reader036.vdocuments.site/reader036/viewer/2022062709/558e471a1a28ab51268b4704/html5/thumbnails/22.jpg)
Asphalt Binder Modified Binders 22
QUESTIONS?