12/11/2013 1 Improving Sustainability of Asphalt Mixtures Using High Binder Mixtures Using High Binder Replacement and Alternative Binders Hasan Ozer Imad L. Al-Qadi, and David L. Lippert Illinois Bituminous Paving Conference, 2013 Asphalt Mixtures & Sustainability High-performance and durable mixes to reduce frequency of maintenance and rehabilitation frequency of maintenance and rehabilitation treatments and provide smooth riding surface SMA, Open-graded asphalt mixture, fatigue resistant lower binder mixtures Lower environmental footprint with replacement of virgin constituents (aggregate and binder) with recycled materials industrial by products with recycled materials, industrial by-products, and non-petroleum products Warm-mix asphalt technology RAP, RAS, RCA, steel slag, etc. Bio-binder alternatives
Transcript
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Improving Sustainability of Asphalt Mixtures Using High BinderMixtures Using High Binder
Replacement and Alternative Binders
Hasan OzerImad L. Al-Qadi, and David L. LippertQ , pp
Illinois Bituminous Paving Conference, 2013
Asphalt Mixtures & Sustainability
High-performance and durable mixes to reduce frequency of maintenance and rehabilitationfrequency of maintenance and rehabilitation treatments and provide smooth riding surface SMA, Open-graded asphalt mixture, fatigue resistant
lower binder mixtures
Lower environmental footprint with replacement of virgin constituents (aggregate and binder) with recycled materials industrial by productswith recycled materials, industrial by-products, and non-petroleum products Warm-mix asphalt technology
RAP, RAS, RCA, steel slag, etc.
Bio-binder alternatives
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Why Binder Replacement?
Economic and environmental impact of asphalt binder in the production of asphalt mixesbinder in the production of asphalt mixes
0 15
0.2
0.25
0.3
0.35
40
50
60
70
80
gy (MBTU
)
ton CO2 EQ)
Material Production per ton of a Surface HMA Mix
GWP per ton
Energy per ton
0
0.05
0.1
0.15
0
10
20
30
Aggregate RAP Binder
Energ
GWP (t
5-6% of mix design by weight BUT > 90% of energy and GWP of total materials impact
Asphalt Binder Replacement Pathways RAP & RAS
Crushing, screening,
Direct
Biomass Fuels
fractionation Direct replacement of asphalt binder
Chemicals
Fertilizers
Paving Binder
Bio Refineries
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What are the Questions?
Does the alternative binder or replacement meet current binder specifications?current binder specifications? Predictable and comparable coating behavior
Predictable and comparable flow characteristics
Predictable and comparable mechanical properties
Predictable and comparable aging characteristics
Predictable and comparable adhesive properties
High ABR* Mixes
Mix Type %ABR %RAP %RAS Slag RCA
IL 19 mm N50 50 42 4IL-19 mm N50 50 42 4 - -
IL-19 mm N50 60 42 6 - -
IL-9.5 mm N70 25 29 - - -
IL-9.5 mm N70 38 30 6 - -
IL-9.5 mm N70 50 30 5 - -
IL-12.5 mm N80 (SMA) 25 8 5 - -
Part of the ongoing ICT R27-128, Performance of High Asphalt Binder Replacement Mixes Using RAP & RAS
IL-12.5 mm N80 (SMA) 50 10 8 - -
IL-9.5 mm TR Joliet 38 30 - 70 -
IL-9.5 mm TR-K5 60 53 5 15 27
IL-9.5 mm TR-Sandeno 57 52 5 15 30
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Complex Modulus Testing (AASHTO TP62-03)
Complex modulus testing were conducted for all lab compacted mixes to evaluate:all lab compacted mixes to evaluate: Stiffness of the mixes with changing ABR
Test Temperature
(°C)
Test Frequency (Hz)
Mixes
-10 0.1, 0.5,1,5, 10,25
All Lab Compacted
Mixes
4 0.1, 0.5,1,5, 10,25
21 0.1, 0.5,1,5, 10,25
38 0.1, 0.5,1,5, 10,25
540.1, 0.5,1,5, 10,25
Modulus of High ABR Mixes
As ABR increases, increase in modulus with slow loading 1000
10000
N80-25% ABR
N80-50% ABR gand high temperatures
1
10
100
1000
1.00E-10 1.00E-06 1.00E-02 1.00E+02 1.00E+06
Lo
g (
E*
(ks
i))
Log Reduced Frequency (Hz)
N80 50% ABR
10
100
1000
10000
og
(E
* (k
si))
N50-50% ABR
N50-60% ABR
10000N70-25% ABRN70 38% ABR
1
10
1.00E-10 1.00E-05 1.00E+00 1.00E+05
Lo
Log Reduced Frequency (Hz)
1
10
100
1000
1.00E-10 1.00E-05 1.00E+00 1.00E+05
Lo
g (
E*
(ksi
))
Log Reduced Frequency (Hz)
N70-38% ABRN70-50% ABR
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Fracture Tests for High ABR Mixes
Two types of fracture tests are conducted to find cracking resistance of high ABR mixesfind cracking resistance of high ABR mixes
Semi-circular bending (SCB) and disc compact tension (DCT) tests are conducted at low and intermediate temperatures
Low Temperature Fracture Results
SCB tests conducted at -12°C for high ABR mixes in addition to some virgin mixesmixes in addition to some virgin mixes
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DCT Fracture Test Results
DCT tests are also conducted at -12°C for some mixesmixes
Push-pull Fatigue Test
The main purpose is to characterize damage in asphalt concrete withdamage in asphalt concrete with repeated load applications
Cyclic displacements generate uniaxial tension and compression in the specimen
Tests are usually conducted at temperatures from 10 to 20°C andtemperatures from 10 to 20 C and various strain levels (200 and 300 microstrains so far)
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Fatigue Results
50% reduction in modulusin modulus value is used as failure criteria
N80 mixes (25% and 50% ABR) appear to form the upper and lower boundary of fatigue failure
Fatigue Curves
Preliminary fatigue datafatigue data shows an decreasing fatigue life with ABR increase
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Sustainability Assessment of Asphalt Mixes
Life-cycle assessment of high ABR mixes for material and production stage illustratesmaterial and production stage illustrates reduction in energy consumption and CO2
emissions
N70
N80 N50TR
RAP Mixes
N80 N50
Sustainability Analysis of ABR Mixes
Reduction in energyenergy consumption is 2-12% with increasing contents of RAP, RAS, and other recycledother recycled materials
Savings in GHG emissions are within 1-5%
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Fuel and Binder Substitutes
Renewable fuels include liquid and gaseous fuels and electricity derived from biomassfuels and electricity derived from biomass feedstocks
Biomass is a term used to describe any material of recent biological origin referring to: Corn, sugar cane, cellusoic biomass (switchgrass,
mischantus) use in ethanol production
Soybean use in diesel production Soybean use in diesel production
Forestry materials and agricultural residue in diesel production – Biobinder applications
Animal derives waste, municipal solid waste, algae use in diesel production – Biobinder applications
Major Conversion MethodsLignin
Molecular
Smaller molecular chains
Fragmentation(thermo-chemical, chemical methods)
Further
Macromolecules in Biomass
Ethanol, BiodieselBiofuel, BiogasBiobinder, etc.
processing, treatment and separation
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Feasibility Study for Bio-Binder*
Objective is to initially evaluate bio-binder samples separated from bio-crudes obtainedsamples separated from bio crudes obtained through one of thermo-chemical processes (hydro-thermal liquefaction*)
Bio-binder samples from different sources of feedstock are obtained including swine manureand algae
Preliminary testing program includes complex modulus (DSR), MSCR, and viscosity
Chemical and molecular characterization is planned
* Partnering with Professors Yuanhui Zhang and Lance Schideman and Environment-Enhancing Energy Lab
Conversion efficiency – ratio of the amount of fuel energy produced to the amount of fossil
Issues with Bio-Fuels and Bio-Binders
fuel energy produced to the amount of fossil fuel required in the production (i.e. corn has very low efficiency)
Land conversion – we don’t want utilize farming fields for energy production
Performance – predictable and comparable coating, flow, mechanical, and aging characteristics
Illinois Center for TransportationIllinois Center for Transportation
www.ict.illinois.edu
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Testing Program for High ABR Mixes
Low Temperature + Fatigue Cracking
-40°C -20°C 20°C 40°C
Low Temperature Cracking
Fatigue Cracking/ Service Temperature
Permanent Deformation
Low in-service temperatures
Intermediate in-service temperatures
High Temperatures
Temperature and Rate Dependency
Fracture experiments were conducted at a sweep of temperatures and loading ratessweep of temperatures and loading rates
-12°C
0°C
10°CFrom more ductile to brittle fracture failure as temperature decreases
25°C
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Temperature and Rate Dependency
Fracture energy change withchange with loading rate is sensitive to ABR
Fracture energy Fracture energy changes with temperature
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Impact of ABR
A clear linear trend in the reduction of energy and GHG emissions with increasing ABRand GHG emissions with increasing ABR
Definition of Biomass
Biomass is a term used to describe any material of recent biological origin referring toof recent biological origin referring to Energy crops grown specifically to be used as fuel
(fast growing trees, switchgrass, algae)
Agricultural residue or by-products (straw, sugarcane fiber, corn stover)
Forestry by-products (logging residue)
Animal derived waste or municipal waste Animal derived waste or municipal waste
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Illini Algae Project Visit the website for further reading:
![3. Energycushman/books/Numbers/Chap3-Energy.pdffollowing 4 weeks [17, page 118]. The volume to mass ratio is 2 cubic yards per short ton (= 1.7 m3 per metric ton). Typical temperatures](https://static.documents.pub/doc/80x56/5b0983f47f8b9a3d018dce54/3-cushmanbooksnumberschap3-energypdffollowing-4-weeks-17-page-118-the-volume.jpg)
