SAT WORKSHOP

Performance Grading Specifications

for Bituminous Binders

Background to PG Binder Specs

Kim Jenkins

tellenbosch

SAT Workshops

March 2016

Superpave Grading System

PG 64-22

PerformanceGrade

Average 7-daymax pavement

design temp

Min pavementdesign temp

Snapshot SA Binder Classification

40/50 60/70 80/100 150/200

X PG64-16 PG58-22 X

PG64-16 PG58-22 PG58-22 X

PG64-16 PG64-22 PG58-16 PG52-22

PG70-22 PG64-16 PG58-22 PG52-22

6 grades – could be reduced to 4 with only one LT

(2005)

Bitumen Characterization Methods in USA

• 1930s , Pen Grading

• 1960s, Viscosity Grading

• 1993 – PG grading

• 2004- PG (Plus) – more complex

• 2011- MP19 – DRC ( MSCR )

• 2014 – M332 – MSCR

• Emperical / Index

Testing- Pen – Vis.

• Rheological Testing in

LVE range (PG)

• Damage / Non-linear

Testing

Next Steps (2014 + ): Damage Resistance Characterization

• Advanced Tests (LAS, ABCD, SENB, Tg etc)

Bitumen Characterization Methods in USA

• 1930s , Pen Grading

• 1960s, Viscosity Grading

• 1993 – PG grading

• 2004- PG (Plus) – more complex

• 2011- MP19 – DRC ( MSCR )

• 2014 – M332 – MSCR

• Emperical / Index

Testing- Pen – Vis.

• Rheological Testing in

LVE range (PG)

• Damage / Non-linear

Testing

Next Steps (2014 + ): Damage Resistance Characterization

• Advanced Tests (to be explained)

South Africa

Up to 2016

Superpave Binder Specifications

Implemented in 1996-1998 M

odul

us

S=300MPa

G*sinδ=5 MPa

G*/sinδ=.001,.0022 MPaTemperature

Tmin Tavg Tmax

RTFO

PAV-aged

η= 3.0 pa-s

Unaged

135 C

Bitumen

Rheology !

Performance Graded Binders for South Africa

Stellenbosch – South Africa , June 13, 2014

www.uwmarc.org

Advanced Performance Grading:

Taking into Account Non-linearity and Damage

• Linear VE is not sufficient

(NCHRP Report 459)

• Bitumen damage resistance

is very important

• Modified binders are best

at damage resistance

Strainεf

σf

PG- LVE

Non-Linear / Damage

Performance Graded Binders for South Africa

Stellenbosch – South Africa , June 13, 2014

www.uwmarc.org

Resolution 1The conference charges Sabita to convene an

international binder expert group meeting in

2015, to process the PG concepts developed

at CAPSA 15, for the purpose of formulating a

PG specification for trial implementation by

SANRAL

(CAPSA, August 2015)

Performance Graded Binders for South Africa

Stellenbosch – South Africa , June 13, 2014

www.uwmarc.org

The Franschoek Declaration 16 Oct ‘15

Challenges

• Long Term Ageing of Binder for SA X none

• PAV equivalency to field ageing

• Seals vs Asphalt

• Binder blind

• No binder grades

• LT damage in SA?

What has been achieved so far?

• Courses (ACBT@SUN) [5]

• Workshops @SUN, Sabita, SANRAL [6]

• RPF Working Group Meetings [15]

• Position Papers & STAR [5+]

• Expert Consultation:– Martin van de Ven, Hussain Bahia

– Geoff, Rowe, John D’Angelo

– Louis Francken, Gert van Gooswillegen, Simon Watkins, Andre Stawiarski, Bob Klutz, Mike Southern, and others

Key questions

• What are we aiming to achieve with PG specs?

• What is the benefit to industry?

• An entirely fundamental, theoretical

specification is unlikely... Healthy dose of

empiricism?

• Implementable protocols for Specs?

– Product “fitness for purpose”

– Site QC

Joining the curve

at an elevated

level!

Thank you!