Delmar Salomon Pavement Preservation Systems, LLC

Pavement Performance Prediction Symposium Laramie  WyomingLaramie, Wyoming

July 15, 2010 

P iPresentation

• OverviewETG E l i t k f• ETG Emulsion task force

• Traditional Emulsified asphalt testsCurrent Specifications• Current Specifications

• Examples of flow properties of emulsified asphalt• Future tests• Future tests • Viscosity,and residue recovery new developments• Summaryy

Direction of emulsion industry

Seeking performance standards Evaluating  fast, automated, residue recovery 

d   li bl     ll  l ifi d  h lprocedures applicable to all emulsified asphalts Tests residue on  DSRE l i   l i     f  i   i i Evaluating alternative ways of measuring viscosity

Emulsion task force formed to accelerate  and transition to some form of rheological test and transition to some form of rheological test and preliminary performance standards

Emulsified Asphalt DefinitionEmulsified Asphalt Definition

When asphalt is milled into microscopic particlesWhen asphalt is milled into microscopic particlesand dispersed in water with an emulsifier,it becomes an emulsified asphalt p

Asphalt Institute MS-19

Emulsified Asphalt compositionEmulsified Asphalt compositionEmulsified Asphalt compositionEmulsified Asphalt composition

water 30water 30--50%50%

solvent 0solvent 0--10%10%chemicals 0.2chemicals 0.2--2.5%2.5%

asphalt 40asphalt 40--70%70%

Rheological Properties of EmulsifiedRheological Properties of Emulsified Asphalt

Emulsion properties, such as stability, workability, breakingand curing, are associated with the rheological propertiesof the emulsified asphalt.p

Current specifications do not give a clear relationshipbetween the emulsion rheological properties and their fieldbetween the emulsion rheological properties and their fieldapplications.

Chip seal spraying application

What emulsion flow properties we need to understand this field application/practice???application/practice???

Breaking, setting and curing:Breaking, setting and curing:

Breaking/Setting: Breaking/Setting: Emulsion Emulsion is destabilized and is destabilized and no longer can be diluted in waterno longer can be diluted in water

Curing: Curing: Water Water and solvent is lost from the and solvent is lost from the system and the final properties of the residual system and the final properties of the residual asphalt are reachedasphalt are reachedasphalt are reachedasphalt are reached

Emulsified asphalt applications

Surface  treatments(functional)

Structural

Fog seal

Chi   l

Cold in place recycling (CIR)

Full depth reclamation Chip seal

Tack coat

Full depth reclamation (FDR)

Slurry Seal

Mi f iMicrosurfacing

Cape seal

Scrub seal

Traditional Tests Methods

High Float Emulsions anionicHigh Float Emulsions anionic emulsions  (ASTM D139)

PassFailFail

ASTM D7496AASHTO T-59

Penetrometer

ASTM D 5

St d d Di till ti Pi t (ASTM D6997)Standard Distillation Picture  (ASTM  D6997)

V Di till ti S h ti (ASTM D7403)Vacuum Distillation Schematic (ASTM D7403)

D ili f h l d El i RD ili f h l d El i RDuctility of asphalt and Elastic RecoveryDuctility of asphalt and Elastic Recovery

Emulsified Asphalt Traditional Tests and Emulsified Asphalt Traditional Tests and ifi tiifi tispecifications specifications

ASTM 977 emulsion specifications (covers 13 grades)p ( g ) D2397 emulsion specifications Cationic (7 grades) AASHTO M 316-99 “Polymer Modified Cationic y

Emulsified Asphalt (for CRS-2P and CRS-2L) TESTS: ASTM D-139 Float Test (for anionic high float

emulsion)ASTM D 113 D ili ASTM D 113 –Ductility

ASTM D 5 Penetration (AASHTO- T49)ASTM D 6084 El ti R ASTM D 6084- Elastic Recovery

Emulsified Asphalt Traditional TestsEmulsified Asphalt Traditional TestsEmulsified Asphalt Traditional TestsEmulsified Asphalt Traditional Tests ASTM D6997 Residue by Distillation (AASHTO-T59)

ASTM D 6934 R id b E ti (AASHTO T59) ASTM D 6934 Residue by Evaporation (AASHTO-T59) ASTM D 7403 Residue by low temperature vacuum

distillation ASTM D 7496 viscosity by Saybolt Furol viscometer

(AASHTO – T59) ASTM D 6930 storage and stability of emulsified asphalt ASTM D 6930 storage and stability of emulsified asphalt ASTM D 6933- Oversized particles (sieve test) (AASHTO-

T59 ASTM 6936 Demulsibility of emulsified asphalt

(AASHTO-T59)

ARIZONA Emulsion specs: use ofARIZONA Emulsion specs: use of rheological tests for residue

Residue will be obtained in accordance with therequirements of  Arizona Test Method 504 and shallconform to all the requirements of AASHTO M 320 for PG 64‐16, except that for CRS‐2 the dynamic shear(G*/Sin ∆) on the original residue shall be a minimum(G /Sin ∆) on the original residue shall be a minimumof 1.00 kPa and a maximum of 1.50 kPa (Table 1005‐3: section 1005 “Bituminous Materials”)

Emulsified Asphalt new/proposed Tests Emulsified Asphalt new/proposed Tests for selected emulsified asphalt for selected emulsified asphalt

titipropertiespropertiesASTM D 7497 practice residue by low temp evaporative

techniqueqDXXXX-YY Proposed practice developed at TXDOT (silicone mat 

with the emulsified asphalt into a 60ºC +/‐ 2ºC forced draft oven for 6 hours +/‐ 15 min)

ASTM D 7404 Residue by moistures analyzer (MAB) ASTM D 7226 viscosity by rotational Paddle viscometerS 6 y y Under review by Emulsion task force-ETG for

testing residue: ASTM D 7405- Multiple Stress Creep & RecoveryCreep & Recovery

ASTM D7229‐06 Superpave Gyratory Compactor for Cold Mix Asphalt: Determination of Bulk Density of CMA

Emulsified asphalt applications

Surface  treatments(functional)

Structural

Fog seal

Chi   l

Cold in place recycling (CIR)

Full depth reclamation Chip seal

Tack coat

Full depth reclamation (FDR)

Slurry Seal

Mi f iMicrosurfacing

Cape seal

Scrub seal

Significance of viscosity forSignificance of  viscosity foremulsified asphalt

The viscosity of emulsified asphalts characterizes their flow properties and affects their utility  at specified temperatures. An emulsified asphalt sprayability and p p p y yworkability is directly related  to their viscosity for many applications types. The material must be thin enough to be sprayed yet thick enough such that it will not flow from the p y y gcrown or grade of the road. For mixing grade emulsified asphalts the viscosity will affect its workability and resulting film thickness on the aggregate. Any test method g gg g yis useful to measure the apparent viscosity of emulsified asphalt at a temperature of 50°C (122°F) or another agreed‐upon temperature.  p p

Effect of constant shear at 50 RPM and 70 oC on emulsion viscosity

300

250 microstructure breakdown

200

Pa s

)

steady-state viscosity

breaking of emulsion

150

Visc

osity

(mP

50

100

V

0

50

0 20 40 60 80 100 120 140 160 180 2000 20 40 60 80 100 120 140 160 180 200

Time (minutes)

Effect of constant shear at 50 RPM and 50oC on emulsion viscosity

350.00

400.00

microstructure breakdown

250.00

300.00

Pa s

)

breaking of emulsion

150 00

200.00

cosi

ty (

m

steady-state viscosity

100.00

150.00

Visc

0.00

50.00

0 10 20 30 40 50 60 70 80 90 100 110 120

Time (minutes)

Summary of rate constants and relaxation times f d ff l f lfor different emulsions from a rotational viscometer

Emulsions K (min-1) R2 relaxation time (min)( ) ( )CRS-2R 0.131 0.99 8

CMS-2P 0.106 0.99 9

CRS-1P 0.090 0.99 11

CRS-2 0.082 0.99 12

CMS-2S 0.078 0.97 13

CRS-2P 0.059 0.99 17

HFRS-2* 0.031 0.99 32

HFRS-2P 0.025 0.99 40

Source: Salomon & Palasch “Kinetic Properties of Emulsified Asphalts, 2000

Rotational viscometer vs. Saybolt

600

700

R2 = 0.7968400

500

600

y (m

Pa

s)

100

200

300

Vis

cosi

ty

050 100 150 200 250 300 350

Saybolt Viscosity (Saybolt Furol second)

Malvern(rot Vis ) vs SayboltMalvern(rot.Vis.) vs. Saybolt

500

600

R2 = 0.7951

300

400

500

ty (m

Pa

s)

100

200

Vis

cosi

0100 150 200 250 300 350

Saybolt Viscosity (Saybolt Furol second)

Digital Paddle Viscometer vsDigital Paddle Viscometer vs. Saybolty

1200

R2 = 0.9034600

800

1000

ty (m

Pa

s)

200

400

Vis

cosi

00 50 100 150 200 250 300 350

Saybolt Viscosity (Sayvolt Furol second)

Linear Viscoelastic Regionf ti i l i (St S )for cationic emulsion (Stress Sweep) 

100

10

100Linear region: below 0.1

Pa CRS-2P

1

10

G*

(Pa) CRS-2

1 CSS-1Most stable

00.01 0.10 1.00 10.00 100.00

Stress (Pa)

Example of simulated sprayExample of simulated spray application

Time Sweep Test (3‐step test) Simulate asphalt emulsion spray application)

Time Sweep Test: 3‐step protocol Temperature at 30C with continuous shear 3 steps

S (S i h k) Th l b i d Step 1 (Storage in the tank): The sample was submittedto a shear rate of 0.1 s‐1 for 180 seconds.

Step 2 (Spraying and pumping): The shear rate was thenStep 2 (Spraying and pumping): The shear rate was thenincreased to 100 s‐1 for 180 seconds.

Step 3 (Setting): The shear rate was decreased to 0.1 s‐1. The viscosity versus time plot

Flow Behavior: storage,spraying,setting storage spraying setting

120%

140%

ty)

Step 1 Step 2 Step 3

CRS-2P

storage spraying setting

80%

100%

ity R

atio

ia

l visc

osit

CRS-2

20%

40%

60%

Visc

osi

% o

f ini

ti

CRS-2CMS 2

CMS-2

0%

20%

0 100 200 300 400 500 600 700

(% CMS-2CRS-2P

Time (s)

Residue RecoveryResidue RecoveryResidue Recovery Residue Recovery Evaporation of WaterEvaporation of Water

••Evaporation of water forces droplets Evaporation of water forces droplets together and eventual coalescencetogether and eventual coalescence

MOISTURE ANALYZER BALANCE

MAB (LOADED)

MAB l t DSRMAB sample to DSR

Future tests: directions forFuture tests: directions forindustry**   

High road temperature stiffness to prevent loss of aggregate in summer. This could be G*/sind or an MSCR test (use DSR)MSCR test (use DSR).

Aging simulation like PAV. This might include a smaller diameter pan to enable use of smaller samples of emulsion residue, but same depth as the standard PAV to not complicate the aging in comparison to standard PAV TTI PAV to not complicate the aging in comparison to standard PAV. TTI determined that PAV was like a year of roadway aging for chip seal binders.

Low temperature test with a maximum stiffness to  l   f   i   i  Thi   ld b    prevent loss of aggregate in winter. This could be a 

DSR at low temp or extrapolated to low temp.??

**Source: some DOT suggestions

Source: Emulsion Task Force-Gayle King

Revised Strawman SpecificationEmulsion Residue Recovery & Testing

Purpose Test Conditions ReportResidue Recovery Forced Draft Oven B) 6 hrs @60ºC, or

A) 24 hrs @ambient +  h   C

% Residue

24 hrs @60ºCTests on Residue from Forced Draft OvenHigh Temperature (Rutting/Bleeding)

DSR Th  (w/ offset TBD) JnrG* / sin δ(Rutting/Bleeding) G* / sin δ

Polymer Identifier(Elasticity/Durability)

Single Stress DSRCreep Recovery

TBD % Recoverable Strain

High Float Identifier  DSR – TBD Test to be High Float Identifier (Bleeding)

DSR non‐linearity

TBD Test to be developed

Tests on PAV after Forced Draft Oven ResidueLow Temperature   DSR freq sweep 10 & 20º C  G* p(Aged Brittleness)

q pModel low T Phase Angle

Sweep test on aged sample

TBD % mass loss

R bl Polymer Degradation(Before/After PAV)

Single Stress DSRCreep Recovery

TBD Recoverable Strain Ratio

Th = high pavement temp; DSR = dynamic shear rheometer; TBD –to be determined

Other Studies for consideration

Bitumen Bond Test (Hussain , Hanz, Miller)Fi ld  i i Field viscosity

DSR G*/sin δ@ climate  temperature Test still to be considered Test still to be considered

DSR single stress creep recovery Higher strain, longer loading, lower temp, higher stressg , g g, p, g

Long term aging Less severe PAV or Sweep test before & after aging

Albedo is the percentage of incoming radiation reflected off a surface  Albedo is the percentage of incoming radiation reflected off a surface. An albedo of 1 means that 100% of incoming radiation is reflected (no radiation is absorbed); an albedo of 0 means that 0% of incoming radiation is reflected (all radiation is absorbed).( )

Pavement Type Albedo h l ( ) 0 0Asphalt (new) 0.05

Asphalt (weathered) 0.06 – 0.15

Source:Lawrence Berkeley National Laboratory Report LBNL-48334, Berkeley, CA.

Summary: Priority items, first steps to standardizationstandardization

Residue Recoveryl h l l d f f f Preliminary rheological definition  of  a surface 

performance binder  values Adhesion  of binder to aggregates (test method??) Adhesion  of binder to aggregates (test method??) other on‐going fundamental research 

DSR  using 4 mm platesDSR  using 4 mm plates WRI ‐ Fundamental Properties Contract UW – Asphalt Research Consortium Contract

Publications and Resources Manual for Emulsion‐Based Chip Seals for Pavement Preservation‐

NCHRP #14‐7 (end:2‐13‐2009) Good Roads Cost Less: UTAH DOT Office of Research (2007) A h lt E l i  T h l  TRB Ci l  EC102   Asphalt Emulsion Technology, TRB Circular, EC102, August,2006

Asphalt Emulsion Technology, TRB Circular , EC‐122f h l l d d bReview of Asphalt Emulsion Residue Procedures, October, 2007

Basic Asphalt Emulsion Manual, AEMA &  Asphalt Institute (see www.aema.org )

www.pavementpreservationsystems.com for publications on emulsified asphalt