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AAPA training

Bitumen & Binders

Bitumen – What is it?

Bitumen Production

Atmospheric  Dis�lla�on  at  300–350oC  

Vacuum  dis�lla�on  producing  bitumen  and  /  or  short  residue.  

Short  residue  air  blown  or  mixed  with  harder/so�er  grades  to  make  bitumen  

Bitumen – how does it behave? Stiffness is time and temperature dependent

Stiff at:

  High loading rates

  Low temperature

Soft at:

  Slow loading rates

  High temperatures

Bitumen – how does it behave? Thermoplastic

–  Inert solid at low temperatures> 25oC

–  Liquid at temperatures +100oC

Bitumen – why we use it? Waterproofing

The glue in asphalt and sprayed seals

Adhesive

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Bitumen – where we use it

  Roofing   Paints   Electrical insulation   Paving

– Asphalt – Spray sealing

Bituminous Binders Supply (2014)

Shell  Townsville  

Darwin  

Shell  Port  Botany  Caltex  Port  Botany    

Shell  Geelong  

Shell  Birkenhead  

SAMI  Fremantle  BP  Kwinana  

Bitumen  Singapore  

Estimated 800k tonnes annual bitumen usage

NSW  185Kt  -­‐  QLD  320Kt  –  VIC  160  Kt  -­‐SA  55Kt  –  WA  60Kt  –  NT  5Kt  –  TAS  15Kt  

Shell  Pinkenba    BP  Bris  Import  SAMI  Bris  Import  

BP  import  

SAMI  Geelong  Import  

BP  Import  

Import  Terminals  Hot  Bitumen  

Refinery  

Bitumen  Plant  

Shell Broome

Shell Port Hedland

(both  import)

Sealing

Asphalt

Binders for roads CUTBACK  BITUMEN  

• Priming  • Primersealing  • Sealing  • Cold  mix  

POLYMER  MODIFIED  BINDERS  (PMBS)  

• Sealing  • Asphalt  • Crack  filling  

BITUMINOUS  EMULSION  

• Priming  • Primersealing  • Sealing  • Cold  mix  • Crack  filling  

Bitumen

Multi-grade Bitumens

Produced as a result of a change to the manufacturing process resulting in

  Reduced temperature susceptibility

  Increased rut resistance

  Superior adhesion

  Improved fatigue performance

Mulitgrade

Visc

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Temperature

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Cutback Bitumen   Bitumen + cutter

–  Kerosene, flash point of 40 - 45C –  High Flash Cutter flash point of 60 - 65C

  Manufacture of –  Primes

(45 – 55% cutter)

–  Primerbinders (10 – 20% cutter)

–  Cold mixes

Temporarily reduce the viscosity allowing more time to apply aggregate Quantity of cutter depends on:

§  Ambient air temperature §  Traffic volume §  Type and size of aggregate used.

Can reduce risk of aggregate loss in cooler weather.

Cutback Bitumen

Polymer Modified Binders

  Bitumen (C170 or C320) + Polymer   Elastomers

  STYRENE-BUTADIENE-STYRENE (SBS)   POLYBUTADIENE (PBD)   CRUMB RUBBER

  Plastomers   ETHYLENE VINYL ACETATE (EVA)

Polymer Modified Binders Improved performance and longer life   Flexibility

  Adhesion

  Cohesion

  Stiffness

Polymer Modified Binders

Austroads PMB Specification

Specification Framework for Polymer Modified Binders and Multigrade Bitumens (AGPT/T190)

http://www.austroads.com.au/pavements

Spray Sealing Grades

AGPT/T190  

S  -­‐  Sealing  Binder  E  -­‐  Elastomer  R  -­‐  Crumb  Rubber  

Test method Minimum testing frequency(1)

! Class S10E S15E(2) S20E S25E S35E S45R(3)

Binder property

AGPT/T111 Each batch Viscosity at 165 °C (Pa.s) max.(4) 0.55 0.55 0.55 0.8 0.55 4.5(4)

AGPT/T122 Each batch Torsional recovery at 25 °C, 30 s (%) 22–50 32–62 45–74 54–85 16–32 25–55

AGPT/T131 Each batch Softening point (°C) ! 48–64 55–75 62–88 82–100 48–56 55–65

AGPT/T142 Weekly Rubber content by analysis (%) min.(5) NA(6) NA NA NA NA 10

AGPT/T121 3-monthly(7) Consistency at 60 °C (Pa.s) min.(8) 250 700 700 5000 300 1000

AGPT/T121 3-monthly(7) Consistency 6% at 60 °C (Pa.s)(8)(9) TBR(10) TBR TBR TBR TBR TBR

AGPT/T121 3-monthly Elastic recovery at 60 °C, 100 s (%) min.(8) NA NA NA 85 NA 25

AGPT/T121 3-monthly(7) Stiffness at 15 °C (kPa) max. 140 140 140 95 180 180

AGPT/T132 3-monthly Compression limit at 70 °C, 2 kg (mm) min. NA NA NA NA NA 0.2

AGPT/T108 3-monthly Segregation (%) max. ! 8 8 8 8 8 8

AGPT/T112 Annually Flash point (°C) min. ! 250 250 250 250 250 250

AGPT/T103 Annually Loss on heating (% mass) max. 0.6 0.6 0.6 0.6 0.6 0.6

!

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Field Produced Crumb Rubber

S15RF  S  -­‐  Sealing  Binder   15  -­‐  %  Rubber  

RF  –  Rubber  Field  Blended  

Asphalt Grades

A  -­‐  Asphalt  Binder    E  –  Elastomer    P  -­‐  Plastomer  

Torsional Recovery Test Bituminous Binder Selection   Sprayed Sealing

–  Bitumen –  Cutback Bitumen –  Bitumen Emulsions –  Polymer Modified Binders

  Asphalt –  Bitumen –  Bitumen Emulsions –  Polymer Modified Binders

  Maintenance –  Cutback (cold mix) –  Polymer Modified Binders (crack filling) –  Bitumen Emulsions (patching)

Binder Selection - Sprayed Sealing Selection of the binder includes assessment of

Nature of treatment

Aggregate properties

Pavement Condition

Environmental factors

Cutback Primes & Primerbinders

Used for new works – granular, timber, concrete Grades produced fall into three main categories:

–  Australian Standard 2157 Grades –  Proprietary Grades –  Field Produced Grades

Always prime or primerseal a new surface

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Cutback Primers Selection based on:   Surface finish   Material type   Density

Aim for:   Absorption   Matte dark brown

At least 72 hours to cure

Cutback Primerbinders

  Primerbinders used in temporary seals where there were difficulties using primers – Building road under traffic – Cant wait for prime to cure – Cold and damp weather conditions.

  Cutback primerbinders 3 – 6 months to cure.

Cutback Primes & Primerbinders Generic  Grade   AS  2157  Grade     Viscosity  Range  

 (Pa.s  @  60°C)  

Prime  

Light   AMC  00   0.008  –  0.016  

Medium   AMC  0   0.025  –  0.050  

Heavy   AMC  1   0.060  –  0.120  

Primerbinder  

Medium   AMC  4   2.0  –  4.0  

Heavy   AMC  5   5.5  –  11.0  

Unmodified Binders- Sprayed Sealing

The most common bitumen used in spray sealing is Class 170.   Relatively straight roads   Low stress environments   Low to medium traffic levels   No or isolated minor cracking

Most common application areas are:

Polymer Modified Binders for Spray Sealing

HSS  (high  stress  seals)  XSS  (extreme  stress  seals)  

Improving  aggregate  reten�on;  Improving  shear  resistance;  Minimising  bleeding;    

SAM  (strain  allevia�ng  membranes)  SAMI  (strain  allevia�ng  membrane  interlayers)  

Minimising  or  delaying  reflec�ve  cracking;  Improving  water-­‐proofing.      

Binder Selection - Asphalt

The major purposes of binder in asphalt are:   Glue the aggregate particles together   Provide pavement flexibility   Provide design waterproofing qualities

These features can be easily compromised if the bitumen or aggregate is excessively hot during the production of hot mix asphalt.

The temperature of the mix will help to determine how easily the mix will be spread and compacted.

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Binder Selection - Asphalt

  Stiffness of the binder is a major contributor to the stiffness of the asphalt.

  Must determine its optimum content in the asphalt mix.

  Part of the mix design, required aggregate grading and binder content are determined

Polymer Modified Bitumen and Multigrade

PMBs in asphalt can provide;   improved crack control;   rutting and shoving resistance;   fatigue resistance;   aggregate retention ;   resistance to high traffic stresses.

Multigrade in asphalt can provide   rutting and shoving resistance;

Polymer Modified Bitumen for Asphalt

PMBs and Multigrade are used to enhance performance properties of mainly surface courses Overall asphalt performance is affected by the properties of the total mix, not by any one component.

Using a PMB will NOT overcome the deficiencies of poor pavement or mix design or the use of sub standard aggregate or filler.

Importance of binders

0

4

8

12

0 500 1000 1500 2000 2500 3000

Load Repitions, cycles

Deformation (mm), 55°C

C170

C320

C600

PMB

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Crack & Joint Filling

  Pavement cracking allows a path for the entry of moisture.   Treatment will stop or slow down the rate of deterioration and improve the effectiveness of subsequent surfacing treatments.

Crack & Joint Filling

Pavement cracking can be broadly separated into two major types;   Traffic induced by vehicles passing over the pavement;   Environment induced due to temperature variations of the pavement or moisture variations in the sub base material.

Binder Selection - Crack & Joint Filling

Emulsions  

§  CRS  type  used.    §  Can  be  applied  in  damp  condi�ons  §  Small  cracks  less  than  2mm  wide  §  Grit  off  to  prevent  pick  up  

Binder Selection - Crack & Joint Filling

Hot  applied  PMBs  §  Proprietary  products  § Used  in  over-­‐banding  or  rou�ng  and  filling  treatments.    

§  Suitable  for  cracks,  about  5  -­‐  15mm  

§  Cracks  visibly  moving  (0.5  –  1mm  of  movement),  may  need  to  use  in  conjunc�on  with  a  geotex�le