1 / 43

Dan Zollinger Marcello Sanchez Texas A&M University

FAA Airport Pavement Working Group Meeting April 24-26, 2012. Climatic Effects in Airfield Pavement Design and Construction. Dan Zollinger Marcello Sanchez Texas A&M University. Typical Pavement Section. Slab Curling and Warping. Cracking and Delamination. Delamination and Sounding.

leena
Download Presentation

Dan Zollinger Marcello Sanchez Texas A&M University

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. FAA Airport Pavement Working Group Meeting April 24-26, 2012 Climatic Effects in Airfield Pavement Design and Construction Dan Zollinger Marcello Sanchez Texas A&M University

  2. Typical Pavement Section

  3. Slab Curling and Warping

  4. Cracking and Delamination

  5. Delamination and Sounding

  6. Ultra-Sonic Testing <40% Delaminated ~70% Delaminated

  7. Summary: Delamination

  8. Slab Cracking

  9. Temperature-Cracking

  10. Moisture-Based Maturity

  11. Monitoring: Lab Cure Monitoring: Field Cure

  12. Field Monitoring

  13. Compound Ranking

  14. Where is the Innovation in Curing Technology? • Equipment Automation? • Rate of application • Pressure/rate of travel • Bar height • Specification & Evaluation? • Monitor application amount • Monitor quality • New Methods and Materials? • Contractor Incentive?

  15. Slab Curling and Warping

  16. Slab Curling Temperature Gradient Ro Slab Top Tavg Night Day Slab Bottom

  17. σnet= σ-ft

  18. Application Control

  19. Findings Assessment Causes Mitigation PE’s > 0.2 lbs/ft2/h EI’s > 0.800 • Dry and windy weather conditions • Surface wetting behind the paver • Quality of the cure • Compound • Time of placing • Original slab dimensions • Curing quality needs to improve • Potential for problems still exist however • Improved management strategy

  20. CODE_BRIGHT Computational Code • Coupled analysis in porous media • Interaction with the atmosphere (Olivella, 1995;Guimarães, 2002; Sánchez, 2004) • Finite element in space • 1D, 2D and 3D elements • Monolithic coupling • Full Newton-Raphson • Finite difference in time • Implicit time discretisation scheme • Automatic time advance • Mass conservative approach for mass • balance equations • User-friendly pre/post processing of data

  21. THM behavior in porous medium phases Saturated Medium Unsaturated Medium

  22. Solid Liquid Gas Coupled THM Formulation • Balance equations (Olivella, 1994; Guimarães, 2002; Sánchez, 2004) • Mass balance of water (Pl ) • Mass balance of air (Pg) • Internal energy balance ( T ) • Momentum balance ( u)

  23. Constitutive equations and equilibrium restrictions Establish the link between dependent and state variables

  24. Heater 0.019 m (0.75”) 0.1429 m (6”– 0.75”/2) 0.1334 m (6”– 0.75”) 0.1429 m (6”– 0.75”/2) - 29 Pipes @ 6” (0.1524 m) on each row - Total Pipes: 3-row  29-column = 87 P-401 HMA 0.127 m (5 in.) 1 2 0.5144 m (20.25 in.) Concrete slab (12 in) + Insulation (0.25 in) + Concrete base (8 in) 3 2 3 2 1 4 5 Concrete (2.625 in.) 0.0667 m 1 Dense Grade Aggregate 0.1524 m (6 in.) Pipe (0.75 in.) 0.019 m 2 (0,0) Concrete (2.25 in.) 0.0572 m 3 Insulator (0.25 in.) 0.0064 m 4 Subgrade 1.0 m (39.37 in) Concrete (8.0 in.) 0.2032 m 5 4.572 m (180 in.) (15 ft.)

  25. Case 5. Temperature 0.5days

  26. Case 5. RH 1.5 days

  27. Case 5. 3D effects

  28. Formation of Horizontal Delamination Direction of Paving Tensile Stress Evaporation 80~90% rh Stress Distribution Delamination Moisture Distribution ~98% rh Delaminations are more severe in the direction of paving

  29. Case 1 vs Case 2 (Temperature) Case 1 Case 2

  30. Case 1 vs Case 2 (RH) Case 1 Case 2

  31. Where are the Tools? • Paving construction requires curing management • Variable weather conditions • Methods of construction change • Not all curing compounds/methods are created equal • Paving/Slab configurations • Length and width of drag/LT devices • Slab lengths • Subbase types and thicknesses

More Related