HiMA and EME

tellenbosch

Kim Jenkins

SAT SeminarAustralian Delegation 6th September 2011

Principle of HiMA

• A building block in providing Perpetual Pavement = Long lasting road = Revêtements durables = Duurzame verhardingen

• M Thomson (2004) Perpetual? “It’s a hell of a long time”

.Perpetual Pavements

Under ESALUnder ESAL

Limit Bending to < 65(Monismith, Von Quintus, Nunn,Thompson)

Limit Bending to < 65(Monismith, Von Quintus, Nunn,Thompson)

Limit Vertical Compression to < 200(Monismith, Nunn)Limit Vertical Compression to < 200(Monismith, Nunn)

Thick HMA(> 8”)

Base (as required)Base (as required)

Subgrade

Perpetual pavements: is there a strain limit below which there is no fatigue???

Log N

Log ε60με?Endurance limit

Lower layer:Fatigue, higher bitumen contentSufficiently low strain level

No

fat

igu

e?

EME: Enrobe a Module Eleve

• EME has the following specific properties:– Increased stiffness– Increased resistance against fatigue– Increased resistance against permanent

deformation

• EME is used in base layers

Applications EME

• Special heavy loaded lanes• Bridge decks• Industry areas• Airport pavements• Perpetual pavements

• Important: check the low temperature cracking

EME

• The properties are achieved by:– Hard bitumen: special production process,

special crudes (no polymers added)– Higher bitumen content– Optimised grain distribution– Low voids content

• Mix design according French norm NF P 98-140

Sabita HiMA T2 project

Phase IVDrafting of guidelines and specs

Phase IIIValidation through APT,LTPP and lab study

Phase IIPreliminary mix and structural design guidelines

Phase IFeasibility study

CSIR

Flexural stiffness (Bending test) EU

  RM 0/20 C RM 0/14 C

  Complex Modulus At 10 Hz [MPa]

Complex Modulus at 10 HZ [MPa]

Temperature

-10 C0 C

10 C15 C20 C30 C40 C

5 

228002100017200150001280088004500

3.9 

280002310017200141001110059002600

Comparison of HMA Moduli

© CSIR 2006 www.csir.co.za

1

10

100

1000

10000

100000

0.00001 0.001 0.1 10 1000 100000

Dy

na

mic

Mo

du

lus

(M

Pa

)

Reduced frequency (Hz)

BTB Mix

Coarse/SBS

Medium/SBS

HiMA

CSIR

© CSIR 2006 www.csir.co.za

Permanent deformation (RSST-CH)

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

4.5%

5.0%

0 5 000 10 000 15 000 20 000 25 000 30 000

Perm

anen

t str

ain

[%]

Load repetitions

BTB 1 55°C Coarse AE2 55°C Medium AE2 55°CHiMA 55°C Medium 60/70 55°C BRASO 55°C

CSIR

Fatigue results (10 °C 25 Hz)

10

100

1000

10000

1000 10000 100000 1000000 10000000 100000000

ST

RA

IN (M

icro

str

ain

)

Number of load cycles

Strain-fatigue relationship at test temperatures at 70% initial stiffness reduction

Mix 1 (BTB)

Mix 3

Mix 4 (HiMA)

All at 10 Degrees C

CSIR

© CSIR 2006 www.csir.co.za

French mix design – to SAParameter Requirement Result SA equivalent test

Workability(Gyratory compactor)

Max 6% voids after 100 gyrations

5.7 % Gyratory

Durability(Duriez test)

Retained strength: >0.7

0.9 Modified Lottmann

Rutting(Wheel tracker)

Rut depth after 30 000 cycles <7.5 mm

5.2 mm RSST-CH, Wheel tracking

Beam dynamic modulus

15 °C-10 Hz:>14 GPa

17 GPa Beam or cylinder dynamic modulus

Fatigue(Prism)

με for 106 fatigue life: >130

90 με Beam fatigue

CSIR

Gyratory study

Specification Superpave FrenchGyratory angle 1.25 0.82Pressure 600kPa 600kPaRate 30 gyrations/min 30 gyrations/min

CSIR

0.00.51.01.52.02.53.03.54.04.55.05.56.06.57.0

0 50 100 150 200 250 300

Air v

oids

[%]

Number of gyrations

F Sample1F Sample2F Sample3F sample4F sample5S Sample1S sample2S sample3S Sample4S Sample5French

SUPERPAVE

CSIR

0.82°

1.25°

Guideline

Select components

Formulate design grading

Select binder content

Compact gyratory specimens

Workability criteria met?

Durability criteria met?

Dynamic modulus criteria met?

Compact slab

Rut resistance criteria met?

Fatigue criteria met?

Implement!

YesNo

Yes

No

Yes

Yes

Yes

No

No

No

CSIR

Test sites in UK for high trafficked areas (>80 MESA)

Changes after the surveys

• Based on the survey the following changes were made for construction:– Temperatures: paver out temperature

>140 ºC .Compaction completed before the temperature falls below 120 ºC

– Air voids < 6%, air voids 100 mm from any unsupported edge < 8%

EN 13924: 2006. Hard Paving grade

EN 13924:2006. Hard paving grade

Binder propertiesTest

Ref

20/30Modified

20/30

(2011)

10/20

(2011)15/25 Spec

Penetration (10-1mm) 25 29 23 22 15-25

Softening Point (oC) 62.8 64.4 57.2 62.2 55-71

Viscosity @ 60oC (Pa.s) 2713 1318 832 2375 >550

RTFOT:

Softening Point (oC) 69.2 68.2 61.6 67.6≥ Orig.

(Min +2)

(Retained Penetration

(10-1mm))

% of Original

(19)

69

(20)

69

(18)

78

(16)

72.7 ≥ 55

© CSIR 2006 www.csir.co.za

Property Test Method Performance requirements

HiMA base

course

HiMA binder course

Class 1 Class 2 Class 1 Class 2 Class 3

Workability Gyratory

compactor, air

voids after 100

gyrations

ASTM

D6926

≤ 6.3% ≤ 3.8 % 3.2 to 6.3 % for D = 10,

2.5 to 5.7 % for D = 14

Moisture

sensitivity

Modified

Lottman

ASTM

D4867

Refer

Table

10

Refer

Table

10

Refer

Table

10

Refer

Table

10

Refer

Table

10

Permanent

deformation

RSST-CH,

55°C, 30 000

reps

AASHTO

320

≤ 1.7%

strain

≤ 1.7%

strain

≤ 2.3%

strain

≤ 1.7%

strain

≤ 1.1%

strain

Dynamic

modulus

Dynamic

modulus test at

10 Hz, 15°C

AASHTO

TP 62

≥ 14

GPa

≥ 14

GPa

≥ 9 GPa ≥ 14

GPa

≥ 14

GPa

Fatigue Beam fatigue

test at 10 Hz,

10°C, to 70%

stiffness

reduction

AASHTO

T 321

≥ 330

με for

10 E6

reps

≥ 430

με for

10 E6

reps

≥ 360

με for

10 E6

reps

≥ 330

με for

10 E6

reps

≥ 330

με for

10 E6

reps

Conclusions

• HiMA is recognised as having potential for application in SA

• EU tests adapted for SA• Special grade of binder needed• Mix design procedure & guide in place• APT and LTPP still required• Field adaptations in SA still needed

Way forward in SA

• Validate improved mix design,• Perform APT and LTPP,• Finalize mix design and structural design

guidelines

Get it right!!!!....orYou’ll have to dig deep to

escape your potholes

Thank you!