Investigation into Temperature Effect on AASHTO Back Calculated Subgrade Resilient Modulus

Over the past 25 years, Alberta Transportation (AT) has collected successive datasets of Falling Weight Deflectometer (FWD) deflection data over their 21,000 km (almost entirely flexible) highway network. A study was conducted to investigate the variation in back calculated subgrade modulus between two or more test dates in different collection years using AT’s FWD inventory data. Presently, AT uses the AASHTO 1993 method for the design of flexible pavement rehabilitation. The AASHTO 1993 design method only applies a temperature correction to the FWD central deflection, which is not directly used for estimated subgrade support strength, and therefore does not account for subgrade strength variation as a function of temperature at the time of testing. This paper presents a subgrade modulus temperature correction model developed from the FWD inventory data. The model was able to reduce the variation of subgrade modulus by a statistically and practically significant amount. If implemented, the model can be incorporated into the pavement rehabilitation design method to either minimize the risk of an under-designed pavement from using a higher than typical back calculated subgrade modulus, or minimize the risk (added costs) of over-design from using lower than typical back calculated subgrade modulus.

• Corporate Authors:

  Canadian Technical Asphalt Association

  ,   United States 
• Authors:
  • Reggin, A
  • PALSAT, B
  • Riessner, M
  • Juhasz, M
• Conference:
  • Proceedings of the Sixth-Second Annual Conference of the Canadian Technical Asphalt Association (CTAA): Halifax, Nova Scotia
• Publication Date: 2017

Language

• English

Media Info

• Media Type: Print
• Pagination: pp. 401-421.
• Monograph Title: Proceedings of the Sixth-Second Annual Conference of the Canadian Technical Asphalt Association (CTAA): Halifax, Nova Scotia

Subject/Index Terms

• TRT Terms: Conferences; Deflectographs; Flexible pavements; Information processing; Mathematical models; Modulus of elasticity; Pavement design; Subgrade (Pavements); Temperature; Values in measurement
• Uncontrolled Terms: Correction (Mathematics)
• Geographic Terms: Canada
• ITRD Terms: 8018: Canada; 8525: Conference; 6430: Correction; 8655: Data processing; 6187: Deflectograph; 2944: Flexible pavement; 6473: Mathematical model; 5919: Modulus of elasticity; 3055: Pavement design; 2950: Subgrade; 6722: Temperature
• Subject Areas: Highways; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 01668517
• Record Type: Publication
• Source Agency: Transportation Association of Canada (TAC)
• Files: ITRD, TAC
• Created Date: May 3 2018 3:19PM