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), 493-524.. Retrieved from, https://search-proquest com.contentproxy.phoenix.edu/docview/896481505?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, https://static.tti.tamu.edu/tti.tamu.edu/documents/0-6607-2.pdf McGennis, R., Kennedy, T., & Machemehl, R. (1984). Stripping and moisture damage in asphalt mixtures. Texas State Department of Highways and Public Transportation. Retrieved from, Https://library.ctr.utexas.edu/digitized/texasarchive/phase2/253-1-ctr.pdf Pavement. (2012). What is inside this section? Retrieved from, http://www.pavementinteractive.org/category/pavement/ 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), 133-147. doi:10.1080/10298436.2014.925622 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, https://www.divaportal.org/smash/get/diva2:796833/SUMMARY01.pdf 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-BDV30-977-06-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/10.14311/EE.2016.247 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, http://onlinepubs.trb.org/onlinepubs/conf/reports/moisture/03_top3.pdf Test Procedure for OVERLAY TEST (2017). TxDOT Designation: Tex-248-F. Retrieved from, file:///C:/Users/libraryws06/Downloads/bit248.pdf Veeragavan, Ram. (2016). An Investigation of the Performance of Hot Mix Asphalt (HMA) Binder Course Materials with High Percentage of Reclaimed Asphalt Pavement (RAP) and Rejuvenators. Worcester Polytechnic Institute. Retrieved from, https://web.wpi.edu/Pubs/ETD/Available/etd-042816- 163006/unrestricted/rveeraragavan.pdf 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), 505-517. Retrieved from https://search-proquest- com.contentproxy.phoenix.edu/docview/1690628580?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-02-042. Retrieved from, https://www.fhwa.dot.gov/research/publications/technical/ 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 (ENG1711781). 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.