Evaluation of Subbase using the Superpave Gyratory Compactor Mike Panko Kevin McGarvey Casey Hurt Cameron Corini Gregg Stevenson Dr. Beena Sukumaran Dr. Yusuf Mehta Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Background Continuous loading from airplane wheels create ruts in pavement Bigger and heavier planes with complex gear configurations make rut prevention more difficult FAA believes rutting is caused by densification of subbase Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

NAPTF – Rutting Behavior North wheel track of CC3 flexible pavements at 19,500 passes Picture courtesy of NAPTF Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Interface profile measurements in the LFC2 posttraffic trench Field Compaction Interface profile measurements in the LFC2 posttraffic trench Courtesy of Garg and Hayhoe Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Outline Background and Objectives Results from testing on P-154 DGA Field to lab Comparison Conclusions Future Work Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Research Approach SGC Compare Compaction Curves Nuclear Density Gauge Field Compaction Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Variables Angle Pressure # of Gyrations Gyratory Compactor Variables Angle Pressure # of Gyrations Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Shearing Action Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Gyratory Compactor and Soil Parameters Angle Used: 1.25° Pressure Used: 600, 800, 1000 kPa # of Gyrations: 400 Gyrations Water Content Ranges:1-2%, 2-3%, 3-4%, 4-5%, 5-6% Sample Size: 3000 grams Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 P-154 Results Determined OMC using Modified Proctor Compared SuperPave Gyratory Compactor Results to Modified Proctor Determined Compaction Energy using a Pressure Distribution Analyzer Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Compaction Properties of P-154 Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Comparison of SGC and Construction Compaction Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 MDD Placement in P-154 Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

P-154 Comparison of Field and SGC Compaction Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Compaction Energy Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Shear Work Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Vertical Work wv = vertical work (in-lb) P = Pressure (600 kPa ~ 87 psi) A = Cross Sectional Area (28.27 in2) ∆h = change in height of sample (in) Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Compaction Energy per Gyration Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 DGA Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Compaction Properties of DGA Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 MDD Placement in DGA Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

DGA Comparison of Field and SGC Compaction Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Comparison of Energy per Gyration Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 SGC vs. Proctor Tests Energy input from Proctor tests come from impact hammer. The SGC can achieve higher densities than the impact hammer alone. The energy input from the SGC comes from the vertical load applied, and the shearing caused by the gyratory movement, resulting in a higher energy. Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Conclusions The SGC looks promising in evaluating compaction characteristics of unbound material during construction. The results from the SGC appear comparable to the deflection in the field for P-154 and DGA but needs further evaluation. Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Future Work Continue SGC testing at different moisture contents. Obtain better field data for P-154, DGA and P- 209 for comparison with SGC tests. Compare SGC compaction energy to field compaction energy. Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010 Acknowledgements FAA Grant #05-G-016 Dr. Gordon Hayhoe, FAA Several FAA personnel for materials and assistance with the database SRA International personnel for data access and assistance with the database Sukumaran et al. FAA Tech Transfer Conference, April 21, 2010

Questions ?

Comparison of Water Content at Top and Bottom of Sample Date Test Gyrations Pressure (kPa) % Water Added by weight Moisture Content % (Top) Content % (Bottom) Avg. (%) Difference 2/1/2008 1 400 1000 6.0 5.462 5.941 5.70 8.40 2 5.446 5.969 5.71 9.16 3 5.173 6.011 5.59 14.97 4 5.507 5.905 6.97 2/26/2008 500 5.183 6.090 5.64 16.09 5.167 6.041 5.60 15.58 2/28/2008 5.0 3.989 4.241 4.11 6.11 4.177 4.388 4.28 4.93 2/29/2008 4.093 4.368 4.23 6.50 4.351 4.603 4.48 5.63 4.485 4.630 4.56 3.20