1. A comparison between different methodologies used to screen asphalt mixtures when exposed to moisture related distress
Fiona Coomey
Introduction/Background
Results
Discussion
MIST
Hamburg
Mix ID
Design AV %
Traffic Level PG
500
3500
# of passes
Rutting Depth (mm)
SIP
SPWEA440E 4
58-28 
0.9
0.83
14405
6.19
12060
SPWEC440E
1.01
0.91
20000
6.34
18988
SPWEB430E 3
58-28
0.99
0.84
6.75
18995
SPWEB450E 5
0.82
9.83
16797
SPWED430I
58-34
1.3
1.36
11.25
15171
SPWEB440E
58-34 
0.78
0.81
19720
12.5
13962
SPWED440E
1.18
1.26
9916
7319
SPWEB340C
0.87
0.55
• Stripping occurs when there is a loss of adhesion between the asphalt and the aggregate surface.
The cause of the loss of adhesion can be traced back to the moisture in mixes, poor compactions, inadequately dried or dirty aggregate, poor drainage or poor aggregate or asphalt chemistry.
• The loss in adhesion between the aggregate and binder is accelerated by traffic and freeze-thaw cycles.
Objectives:
• To compare two different methods that are commonly used by agencies to screen mixtures for potential moisture related distress issues in the field. 
To evaluate how the two methods rank the 8 different mixtures.
Using the Stripping induction point (SIP) data and the Tensile strength ratio (TSR) data, a comparison is made between two tests
There is a correlation between stripping and water content in the aggregates for both tests
Samples were plotted according to rut depth in mm
All samples were tested with the same temperature and pressure margins
While there is a relationship between the presence of water and the amount of stripping, the two tests rank the mixtures differently
Here are two examples:
Holleran,G., Holleran,I., Jayalath, C. (2012). Overlay Testing and Surface Mixes. AAPA
15th International Conference Brisbane Australia. Retrieved from, file:///C:/Users/libraryws06/Downloads/D2S2-02D-Holleran-Overlay-testing-and-surface-mixes%20(1)%20(1).pdf
Kassem, E., Masad, E., Lytton, R., & Chowdhury, A. (2011). Influence of air voids on
mechanical properties of asphalt mixtures. Road Materials and Pavement Design, 12(3), Retrieved from, com.contentproxy.phoenix.edu/docview/ ?accountid=35812
Lubinda F., Walubita, Abu N., Faruk, Koohi, Y., Rong,l., Scullion, T., & Lytton, R. (2012).
Search for a Test for Fracture Potential of Asphalt Mixes (2012). Texas Department of Transportation and the Federal Highway Administration. Texas A&M Transportation institute. Retrieved from,
McGennis, R., Kennedy, T., & Machemehl, R. (1984). Stripping and moisture damage in
asphalt mixtures. Texas State Department of Highways and Public Transportation. Retrieved from,
Pavement. (2012). What is inside this section? Retrieved from,
Ryo, N., Veeraragavan, A., & Krishnan, J. M. (2016). Influence of confinement pressure
and air voids on the repeated creep and recovery of asphalt concrete mixtures. International Journal Of Pavement Engineering, 17(2), doi: /
Salour, F. (2015). Moisture Influence on Structural Behaviour of Pavements Field and
Laboratory Investigations. Royal Institute of Technology School of Architecture and the Built Environment Department of Transport Science Division of Highway and Railway Engineering. Retrieved from,
Sheng, B. (2016). Evaluation of Florida Asphalt Mixes for Crack Resistance Properties using
the Laboratory Overlay Test Procedure. Florida State University. Retrieved from, file:///C:/Users/libraryws06/Downloads/FDOT-BDV rpt.pdfSofia, A., Fredy, F., & Reyes, A. (2016). Moisture damage analysis through the TSR and
MIST test using water conditioning asphalt. Javeriana University. doi: dx.doi.org/ /EE
Solaimanian, M., Harvey, J., & Maghsoud. (n.d.). Test Methods to Predict Moisture
Sensitivity of Hot-Mix Asphalt Pavements. PaveTex Engineering and Testing VIVEK TANDON University of Texas at El Paso. Retrieved from,
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file:///C:/Users/libraryws06/Downloads/bit248.pdf
Veeragavan, Ram. (2016). An Investigation of the Performance of Hot Mix Asphalt
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Wang, H., Wang, Z., Blight, R. J., & Sheehy, E. C. (2015). Derivation of pay adjustment
for in- place air void of asphalt pavement from life-cycle cost analysis. Road Materials and Pavement Design, 16(3), Retrieved from
com.contentproxy.phoenix.edu/docview/ ?accountid=35812
Mix ID
MIST
SIP
500
3500
SPWEA440E
LowMIST3500
LowMIST500
High SIP
SPWED440E
HighMIST3500
HighMIST500
Low SIP
Methods
The MIST test reproduces three factors:
Stress
Pressure
High temperatures,
TSR is a measure of water sensitivity
TSR is expressed as a percentage
The HWTT uses a steel wheel with weight that rolls over the sample in a heated water.
The HWTT test assesses SIP:
SIP is the point where the creep slope and the stripping slope intercept
SIP is used to evaluate moisture damage potential
The rut depth is measured:
every 20, 50, 100 or 200 passes.
20,000 passes can take around 6.5 Hours
Data from the Moisture Induced Sensitivity Test (MIST) was compared to the Hamburg Wheel-Tracking Test (HWTT)
Conclusion/Summary
The MIST test and the HWTT test were compared to assess their relationship to moisture related distress issues in the field. 
Each test assesses moisture related distress, but the two tests rank the mixtures differently
Literature Cited
Federal Highway Administration Research and Technology. (2000). U. S. Department of Transportation. Publication Number: FHWA-RD Retrieved from,
Htet, Y. (2015). An Assessment of Moisture Induced Damage in Asphalt Pavements. Worcester Polytechnic Institute. Retrieved from, file:///C:/Users/fiona/Desktop/ASPHALT/htet.pdf
InstroTek, Inc. (2016). MIST: Operation Guide. Raleigh, NC: Innovators in Instrumentation Technology
*Other references available upon request
Acknowledgements –This research was supported with funding from the National Science Foundation’s Research Experience for Teachers in Engineering Grant (ENG ).
Thank you to Katie Haslett, Dr. Dave, and Dr. Daniel for sharing your extensive Civil Engineering knowledge.
Special thanks to Steve Hale and Allison Wasiewski in the UNH Leitzel Center for the opportunity to participate and for your support.