a quantitative method for determining - rmaces · a quantitative method for determining by scott...

A Quantitative Method for Determining

by Scott Shuler

and Anthony Lord

Rocky Mountain Asphalt Conference and Equipment Show

2nd Annual Asphalt Research Symposium

Sunday, March 28, 2010

Acknowledgements


Acknowledgements

National Cooperative Highway Research Program


Acknowledgements

National Cooperative Highway Research Program

Project 14-17 “Manual for Emulsion-Based Chip Seals for Pavement Preservation”


What Are Chip Seals?


Aggregate Design


Aggregate

• Spread Rate

Design


Aggregate

• Spread Rate– One Stone Thick

Design


Aggregate

• Spread Rate– One Stone Thick

–Or…..

Design


Design


Getting it One Stone ThickDesign


Getting it One Stone Thick• Follow A Design Method

– South Africa/Australia/New Zealand• Flakiness Index < 25%• ALD/Gradation - One-Sized• Traffic• Texture• Embedment

Design




– Asphalt Institute/McLeod/Hanson• Asphalt Rates Too Low, Aggregate Rates Too High

Design




– Asphalt Institute/McLeod/Hanson• Asphalt Rates Too Low, Aggregate Rates Too High

– Texas/Kearby/Gallaway/Epps• Asphalt Rates Too Low, Aggregate Rates Too Low

Design


Design Gets Us So Far, Then ‘Art’ Kicks in….. Right?



• Turning Traffic Loose– Touchy Feely?– Science ?

• Surface Texture




• Surface Texture– Touchy Feely?– Measure It?





• Surface Resistance– Ball Penetration






• Emulsion Correct on Job?






• Emulsion Correct on Job?– Measure It


Question


Question

• Can a Lab Test be Used to Predict Emulsion or Residue Strength in the Field?


Question

• Can a Lab Test be Used to Predict Emulsion or Residue Strength in the Field?

• If it Could, Maybe Judgment Could be Improved


Chips at One-Stone Thickness


“Pin-Art” Holds ChipsThe ‘Grabber’


Template = 40% Embedment


A Pneumatic Roller Would be an Improvement


NCHRP 14-17“Traffic Simulator”


The Experiment


• AGGREGATES: – Basalt, Alluvial, Granite, Limestone

The Experiment



• EMULSIONS: – RS-2, RS-2P, CRS-2, CRS-2P

The Experiment




• EMULSION CURE: – 40%, 80%

The Experiment




• EMULSION CURE: – 40%, 80%

• AGGREGATE MOISTURE: – Dry, SSD

The Experiment


Experiment Design• Yiklm = µ + Ai + Wk + Ml + AWik + AMil + WMkl + AWMikl + eiklm

• • Where,• Yijklm = Chip Loss, %

• µ = mean loss, %

• Ai = effect of aggregate i on mean

• Wk = effect of water removed (40, 80%) k on mean

• Ml = effect of aggregate moisture l on mean (dry,SSD)

• AWik, etc. = effect of interactions on mean

• eiklm = random error


Aggregates


Aggregates

4.75 8.06.3 9.5

Sieve Size, mm

Pas

sing

, %


Aggregates


AggregatesLS GR BS AL

BSG 2.615 2.612 2.773 2.566Median Size, in 0.252 0.315 0.277 0.277ALD, in 0.170 0.265 0.218 0.222Design Coverage, psy

16.48 26.11 22.95 21.73


Emulsions


EmulsionsRS-2P RS-2 CRS-2 CRS-2P

SF, 50C 108 96 78 119Residue, % 65 68 68 68Pen, 25C, 100g 115 95 125 85Ductility, 25C 100+ 100+ 100+ 100+


Dry Chips - 40% Moisture Loss

Chi

p Lo

ss, %


Dry Chips - 80% Moisture Loss

Chi

p Lo

ss, %


SSD Chips - 40% Moisture Loss

Chi

p Lo

ss, %


SSD Chips - 80% Moisture Loss

Chi

p Lo

ss, %


ANOVA


αααα

Source RS-2 RS-2P CRS-2 CRS-2P

ANOVA


αααα


ANOVA

Aggr <0.0001 <0.0001 0.3887 0.0049


αααα


ANOVA

Aggr <0.0001 <0.0001 0.3887 0.0049Moist 0.0169 0.0220 0.1597 0.0003


αααα


ANOVA

Aggr <0.0001 <0.0001 0.3887 0.0049Moist 0.0169 0.0220 0.1597 0.0003Cure <0.0001 <0.0001 <0.0001 <0.0001


αααα


ANOVA

Aggr <0.0001 <0.0001 0.3887 0.0049Moist 0.0169 0.0220 0.1597 0.0003Cure <0.0001 <0.0001 <0.0001 <0.0001A x M 0.2468 0.3618 0.0994 0.7574


αααα


ANOVA


A x C 0.0001 0.0020 0.3927 0.0005


αααα


ANOVA


A x C 0.0001 0.0020 0.3927 0.0005M x C 0.5425 0.0136 0.9999 0.9546


αααα


ANOVA


A x C 0.0001 0.0020 0.3927 0.0005M x C 0.5425 0.0136 0.9999 0.9546A x M x C 0.1064 0.2088 0.8805 0.0114


Newman-Keuls Multiple Comparison



RS-2RS-2

Allv A

Grn B

LS B

Bas C



RS-2RS-2

Allv A

Grn B

LS B

Bas C

RS-2PRS-2P

Allv A

Grn A

Bas A

LS B



RS-2RS-2

Allv A

Grn B

LS B

Bas C

RS-2PRS-2P

Allv A

Grn A

Bas A

LS B

CRS-2CRS-2

LS A

Grn A

Bas A

Allv A



RS-2RS-2

Allv A

Grn B

LS B

Bas C

RS-2PRS-2P

Allv A

Grn A

Bas A

LS B

CRS-2CRS-2

LS A

Grn A

Bas A

Allv A

CRS-2PCRS-2P

Grn A

Allv AB

Bas AB

LS B


OK, So the Lab Test Works,But What About in the Field?


Arches, NP


Frederick, CO


Forks, WA


Arches, NP

Moisture Loss, %


Frederick, CO


Forks, WA

Moisture Loss, %Sunday, March 28, 2010

Chip LossField Site Aggregates - Lab Sweep Test Results

Moisture Loss, %


Conclusions


Conclusions

• This chip seal performance test may provide a means for comparing strength of aggregate/emulsion combinations under various curing conditions.


Conclusions


Conclusions

• The amount of water remaining in the chip seal emulsion has a large effect on chip retention.


Conclusions


Conclusions

• Significantly higher chip loss was

measured for test specimens

fabricated with dry aggregates

compared with saturated surface

dry aggregates.


Conclusions


Conclusions

• No significant differences in chip loss could be measured either at 40 or 80 percent cure when cationic emulsions were compared with anionic emulsions on either calcareous or siliceous aggregates.


Conclusions


Conclusions

• This Preliminary Data Suggests the New Sweep Test May be Used to Predict “Time to Traffic” for Fresh Chip Seals.


Questions ?


Thank You !


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