HVS Testing at ERDC – Last Five Years J. Kent Newman, PhD Larry Lynch, PhD Geotechnical and Structures Laboratory Engineer Research and Development Center

Outline Introduction HVS Studies Summary APB Mission and History HVS-A Selected projects from last five years Summary

Introduction APB Mission Performs research and development studies for the purpose of developing new and improved methods for the design, construction, evaluation, rehabilitation, and maintenance of structural systems for pavements, rails, and other transportation facilities in support of DOD and USACE. Serves a Tri-Service (Army, Navy, and Air Force) lead for research and development for airfields and pavements by providing technology to support DOD doctrine of global force projection. Responsible for developing models for improved performance prediction; identification of deterioration rates, failure modes, mechanisms, and establishing performance criteria for transportation systems.

History of Corps Airfields and Pavements Research Introduction History of Corps Airfields and Pavements Research HVS-A Testing AAF Evaluation program Railroad program RCC, RMP pavements Polymer-Modified Asphalts Design and construction criteria for B-29 C-5A, B-747 criteria Vietnam Unsurfaced criteria 1940 1950 1960 1970 1980 1990 2000 2010 Heavy-load (B-52) pavements Landing mats Fuel and blast resistant pavements Airfield evaluations Nondestructive testing procedures PCI Bomb-damage repair FRC pavements Layered-elastic design 3-D finite element modeling Advanced materials characterization Rapid Airfield Construction CBR design Improvement Rapid Airfield Repair AM-X Mat Program

Introduction HVS-A Acquired 1998 Purchased to primarily conduct full-scale high traffic testing of airfield pavements Max load 100,000lbs Range of Wheels C-17 single and dual Dual to gauge multiple wheel interactions B-52 Dual C-130 Single F-15 Single Truck Super Single Standard Dual

Last Five Years - HVS Studies Flexible Pavements B-52, C-130, C-17, F-15, Truck Traffic Marginal Bases for Asphalt Revision of CBR Design Geosynthetics Concrete Pavements F-15, C-17 Traffic Rapid Repair – PUR Foams Stabilized Surfaces C-130 Traffic Fiber-Cement Polymer-Cement C-17 Traffic Dust control

Marginal Bases for Asphalts C-17 F-15E Aircraft Weight 586,000 lbs 81,000 lbs Wheel Load 44,930 lbs 35,235 lbs Gross Gear Load 269,560 lbs 35,235 lbs Tire Pressure 142 psi 325 psi Single-Wheel Load Trapezoidal Distributed Traffic Pattern 40’ traffic; 4’ wander width Failure criteria 2” of rutting At selected traffic intervals, the surface will be inspected for distress, permanent deformation will be measured, and falling weight deflectometers tests will be performed. The failure criterion for asphalt concrete pavements is typically based upon 1-in. of permanent deformation or rutting. Each item will be trafficked with about 10,000 passes of the HVS. Upon completion of traffic tests, a forensic investigation will be conducted to determine the failure mechanisms and influence on overall pavement performance.

Marginal Bases for Asphalts Base Course Type Measured Coverage's to Failure Predicted Coverage's to Failure (1” AC Rutting) PCASE CBR LEEP GW (1) 650 560 2300 GM 700 668 1947 SM 450 16 1224 (1) Data obtained from the “Minimum Asphalt Thickness Project ” At selected traffic intervals, the surface will be inspected for distress, permanent deformation will be measured, and falling weight deflectometers tests will be performed. The failure criterion for asphalt concrete pavements is typically based upon 1-in. of permanent deformation or rutting. Each item will be trafficked with about 10,000 passes of the HVS. Upon completion of traffic tests, a forensic investigation will be conducted to determine the failure mechanisms and influence on overall pavement performance.

Revision of CBR Equation Move to a a more mechanistic CBR design Stress-based using Frolich’s approach Eliminates need for α and ESWL ITEM2, ETC ITEM1 5’ 5’ TRAFFIC LANE 1 : F15E TIRE 5’ TRAFFIC LANE 2 : C17 DUAL TIRES 40’ 10’ 5’ 5’ TRAFFIC LANE 3 : C17 SINGLE TIRE 5’ ACTUAL HVS 40’ TRAVEL 5’ 5’ 5’ LENGTH OF EACH ITEM=50’

Tensar Geosynthetics 10,000 lb load Dual Truck Tires at 80 psi NOT TO SCALE 2” 57.5’ 3 CBR CH Subgrade 2” AC 8 CBR 12” 24” Geogrid Where Applicable Structural Number = 1.6 Structural Number = 2.4 80-100 CBR Crushed Stone 6” 30” 10,000 lb load Dual Truck Tires at 80 psi 32 in. Wander Width Failure Criteria: 1” Rut Depth

Concrete Rapid Repair – PUR Foams Basic Concept Remove Ruptured Soil without Compaction Backfill with HD Polyurethane Foam Cover with Rapid Set® Concrete Cap

Rapid Repair – PUR Foams Heavy Vehicle Simulator (HVS) Trafficking Method Traffic repairs with HVS after caps are fully cured Observe repairs at regular intervals to chronicle pavement distresses Loads Configuration: Tandem axles with dual tires Axle loads: 10,000 pounds per axle Traffic up to 50,000 passes or failure Failure Criteria Repair exhibiting cracking or spalling with roughness >1in Crack or Spall widening enough to allow foreign object insertion Section of slab breaking and able to be pried loose

Rapid Repair – PUR Foams ALL craters at Vicksburg and Port Hueneme surpassed the single axle pass limit without distresses causing failure Crater 3 50,000 Passes Virtually no distresses The worst damage observed ~ 1 in Damages are limited to minor hairline cracks Crater 4 50,000 passes Virtually no distresses

Conclusions – Rapid Repair Polyurethane foam and Rapid Set Concrete performed well in conjunction as a Rapid Crater Repair Technique Crater repairs able to withstand in excess of 50,000 single axle passes (1 year of light duty road) Little training required (4 hrs) 4 hr complete repair time (Site prep until ready to traffic) Foam materials must be between 65oF and 85oF (heated or cooled storage necessary) for acceptable foam performance

Stabilized Surfaces C-130 Wheel load 30,000 lb 750 Passes One Day Cure Apron 1 Fiber/Cement Polymer/Cement No Cracks, ½” Rut Cracked at Edge of Wheel Path, 3” rut Unmodified Soil – 6” rut

Dust Control Studies C-17 Wheel Load 38,000 lbs, 142 psi Channelized Traffic Comparing dust on stabilized surfaces Polymer Emulsion Synthetic Oils Heavy Applications vs. Reapplications Gravimetric and Optical Data

Dust Control Studies Conclusions Polymer emulsion best for stabilized surfaces High app rate best when possible Synthetic oils best for unmodified soils Softened cement-stabilized surface Optical data from Hazdust monitors provide real time dust levels Maybe subject to overranging with fine soils

Conclusion HVS very useful for wide-range of studies Durable Multifunctional Adaptable

Questions?