AAPA 2012 Study Tour to Europe – High performance asphalt and binders – Part 2 v1 High performance asphalt and binders Part 2

AAPA 2012 Study Tour to Europe – High performance asphalt and binders – Part 2 v1

High performance asphalt and binders

Part 2


1. Long life pavementso Experience, design systems, use, durability & performance

2. High performance asphalt & binderso High modulus asphalt (EME, HiMA), modifiers

3. Sustainabilityo RAP/WMA, bitumen substitutes, carbon calculators & energy analysis

climate change impacts, societal concerns

4. Health & Safetyo Construction of road works, health considerations for bitumen

and asphalt products

5. Procurement Systemso Proprietary products (Avis Technique, HAPAS, etc.), “green” procurement,

REACH, responsible sourcing, PPP and contract models

www.aapa.asn.au

2012 Study Tour Key Topics 2012 Study Tour Key Topics


Topic 2: High performance asphalt & bindersTopic 2: High performance asphalt & bindersOverview of reasons•Bituminous binders key component in the performance and service life of bituminous surfacings & asphalt pavements•About 90% of the Australian all weather road network length is surfaced with sprayed seals about 50% of binder usage•Need to ensure optimum asphalt & seals performance in the field, and to promote best practices suitable to be adapted & adopted in Australia. Seeking details on:

o new developments and test methods in high performance asphalt and bituminous materials (e.g. HiMA /EME, PMB, Emulsion)

o actions taken by European and others (e.g. binder manufacturers, asphalt producers and researchers) to overcome field problems (e.g. climate change)

o correlation between laboratory test results and field trials

www.aapa.asn.au


Binder Specification and

PMB Testing

Khar Yean Khoo


European Specifications for Bituminous Binders

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Bitumen industry position report (2012)Bitumen industry position report (2012)

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BinderBinder standards standards1st generation:1st generation: harmonisation of national

existing standardso based on conventional test methods, completed

2nd generation:2nd generation: development of performance-related standardso project started in 2000, in progresso under responsibility of CEN TC 336 Bituminous

Binders.


European standard developmentEuropean standard development

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CEN TC336Bituminous

binders


CEN TC336Bituminous

bindersData Collection

new testsdata on binders

BiTVal Project

correlation with performancespecification recommendations

Task Groups

TG1 High service tempsTG2 Low service tempsTG3 Ageing- conditioning


First generation − bitumenFirst generation − bitumen

based on conventional test methods

R & B PENETRATION.


Framework Specification for PMB − EN Framework Specification for PMB − EN 14023 (mandatory)14023 (mandatory)

• penetration• softening point• cohesiono force-ductilityo tensile test at 5 Co Vialit pendulum (surface dressing)

• durability (RTFOT or RFT)o mass loss, retained pen, increase in S Pt

• flash point

After long discussion, eventually agreed on:


Framework Specification for PMB −Framework Specification for PMB − EN 14023 (EN 14023 (optional))

• Fraass breaking point

• elastic recovery

• plasticity range (S Pt – Fraass BP)

• storage stability (delta S Pt & pen)

• fundamental tests (to be reported)o DSR, BBR, deformation energy


Elastic recovery − not an Australian testElastic recovery − not an Australian test

• A bitumen test sample is stretched at a constant speed predetermined elongation (200 mm).

• The thread of bitumen thus produced is then cut in the middle to obtain two halves.

• After leaving for 30 min, the distance between the two ends of the threads is measured.


Future binder specificationsFuture binder specificationsIndustry task force concluded in 2012: Industry task force concluded in 2012:

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• a new specification is only required for rheologically complex materials such as:– PMBs

– hard paving grade bitumen

• rheologically simple bitumen meeting EN12591 does not require new specifications


Second Generation StandardsSecond Generation Standards

• first generation specs based on traditional empirical tests

• performance related specs required by Construction Products Directive

• performance related standards will cover a broader range of products and stimulate new development

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Note: binder adhesion will not be addressed. It is important but no easy test method exists or will be developed soon.Need to cover under asphalt properties

these are needed because: these are needed because:


SummarySummary• Europeans began development of performance

related specifications in 1995

• there was great diversity of test and specs among different countries

• first generation specs (1999 – 2005) concentrated on harmonisation and simple, traditional test methods − these are considered unsuitable for PMBs

• second generation specifications are required but need input from users

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PMB Testing

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PMB test methodsPMB test methods• no really new tests

• focus is on finding a PMB property related to asphalt rutting

• SHRP used Dynamic Shear Rheometer (DSR) parameter: G*/sin - but poor correlation

• Europeans - Zero Shear Viscosity (ZSV) using DSR

• then easier to obtain Low Shear Viscosity (LSV)

• latest is U.S. DSR parameter: non recoverable creep compliance (Jnr) − from the Multiple Stress Creep Recovery (MSCR) test


Concept of ZSV and LSVConcept of ZSV and LSV

Typical PMB viscosity behaviour in high service temperature (e.g. 60 C)

Typical bitumen viscosity behaviour in high service temperature (e.g. 60 C)

Log viscosity

Log shear rate

Zero shear viscosity

Low shear viscosity

Apparent viscosity

Low shear rate (e.g. 0.0001 s-1)

‘Imaginary zero’ shear rate

Source: ‘Austroads 2010, ‘Laboratory study on relationship between binder properties and asphalt rutting’, AP-T164/10

ZSV

LSV


Papers reviewedPapers reviewed• results from Argentinian and German papers

presented at the 5th Eurobitume & Eurasphalt Congress

• these relate asphalt laboratory wheel tracking with binder tests:o Zero Shear Viscosity ZSVo Low Shear Viscosity LSVo Multiple Stress Creep Recovery MCSR

• then will compare with Australian Consistency correlations


Argentinian LSV Argentinian LSV vs.vs. WT − paper 410 WT − paper 410• 3 asphalt typeso dense 20 mm (D-20)o micro 10 mm (M-10)o SMA 10 mm (SMA-10)

• 3 binder typeso conventional bitumen (C)o Multigrade (M)o SBS PMB (PM)

• Testingo Binders: DSR testing to get LSV at 60 Co Asphalt: Wheel tracking (rutting rate at 60 C shown)


R2 = 0.87


BP German study – paper 402BP German study – paper 402

• 5 normal paving grade (NPG)• 11 PMBso 7 < 4% additiveo 4 > 4% additive

• 2 low viscosity wax modified (NV)• 2 special bitumens (SP) – Multigrade (MG) and

Phosphoric acid modified

Binders

Asphalt 50 mm slabs of hot rolled asphalt (6.9% binder conten

t） Wheel tracked at 45 C and 60 C


German study RGerman study R22 values for three tests values for three tests

Property Binder condition

R2

Softening Point fresh 0.68ZSV fresh 0.49Jnr fresh 0.79

Jnr RTFOT aged 0.90


MSCR test conditions (for JMSCR test conditions (for Jnrnr))• load applied for 1 s, recover for 9 s

• further 10 creep/recovery cycles

• repeated for 4 stress levels (30, 100, 300, 1,000 Pa)

PMB

CRMB

Hv PMB


Wheel tracking rut rate Wheel tracking rut rate vvs. Js. Jnrnr of RTFOT of RTFOT aged bitumen at 45 aged bitumen at 45 C and 60 C and 60 C C

R2 = 0.90


Consistency (Oliver 1998)Consistency (Oliver 1998)

R2 = 0.89


Reciprocal plot (Urquhart 2010)Reciprocal plot (Urquhart 2010)


Consistency @ 5% strain (Choi 2010)Consistency @ 5% strain (Choi 2010)


ConclusionsConclusions• DSR parameters used to predict rut resistance:o Jnr from MCSR best (using aged binders)o LSV satisfacotry (reciprocal relationship)o ZSV poor in reported study

• Elastometer Consistency gave good prediction and will be improved byo using Consistency 5% or 6% (Choi & Urquhart)o reciprocal relationship (Urquhart)

• Consistency reciprocal plot is useful for developing specification limits


Thank YouThank You

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• Adhesion• Constancy / consistency of quality (ITT)• Long Term Ageing

Problems / challengesProblems / challenges

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Which test for which property?• TG1 – High Service Temperatures• TG2 – Low Service Temperatures• TG3 – Ageing-conditioning

TG’s

Challenges• Takes a lot of time• Moving forward (very slowly)• Good test methods are needed


TG1 HIGH SERVICE TEMP

Source: Egbert Beuving, AAPA 2012 study tour PowerPoint presentation


TG2 LOW SERVICE TEMP/CRACKING



TG3 AGEING-CONDITIONING



OTHER REQUIREMENTS



Consistency correlation: RConsistency correlation: R22 summary for 4 summary for 4 mix designsmix designs

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Consistency %

Choi 10mm Urquhart 10mm Urquhart 14mm Remtulla 10mm

5% 0.82 0.77 0.95 0.946% 0.80 0.82 0.96 0.937% 0.79 0.84 0.96 0.928% 0.78 0.87 0.97 0.929% 0.76 0.89 0.97 0.92

10% 0.76 0.90 0.97 0.9215% 0.72 0.93 0.98 0.9220% 0.70 0.95 0.98 0.9325% 0.69 0.96 0.98 0.9430% 0.67 0.96 0.99 0.9450% 0.65 0.96 0.99 0.9580% 0.63 0.96 0.99 0.95

100% 0.63 0.96 0.99 0.96


Consistency 6% correlation (Urquhart − Consistency 6% correlation (Urquhart − BSWG, Feb 2012)BSWG, Feb 2012)

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Choi 10 mm mix

Fitted curve: Wheel tracking = A / (Consistency 6%) + B

Urquhart 10 mm mix

AAPA 2012 Study Tour to Europe – High performance asphalt and binders – Part 2 v1 42

Remtulla 10 mm mix

Fitted curve: Wheel tracking = A / (Consistency 6%) + B

Urquhart 14 mm mix

Consistency 6% correlation (Urquhart − Consistency 6% correlation (Urquhart − BSWG, Feb 2012)BSWG, Feb 2012)

ElastometerElastometer

www.aapa.asn.au

a) 50/100 method: conventional Consistency b) 20/40 method: Underlying Viscosity (UV) over 20-40% strainc) Consistency at 5% strain

Documents

AAPA 2012 Study Tour to Europe – High performance asphalt and binders – Part 2 v1 High performance asphalt and binders Part 2