Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30517
Backcalculation of HMA Stiffness Based On Finite Element Model

Authors: Md Rashadul Islam, Umme Amina Mannan, Rafiqul A. Tarefder


Stiffness of Hot Mix Asphalt (HMA) in flexible pavement is largely dependent of temperature, mode of testing and age of pavement. Accurate measurement of HMA stiffness is thus quite challenging. This study determines HMA stiffness based on Finite Element Model (FEM) and validates the results using field data. As a first step, stiffnesses of different layers of a pavement section on Interstate 40 (I-40) in New Mexico were determined by Falling Weight Deflectometer (FWD) test. Pavement temperature was not measured at that time due to lack of temperature probe. Secondly, a FE model is developed in ABAQUS. Stiffness of the base, subbase and subgrade were taken from the FWD test output obtained from the first step. As HMA stiffness largely varies with temperature it was assigned trial and error approach. Thirdly, horizontal strain and vertical stress at the bottom of the HMA and temperature at different depths of the pavement were measured with installed sensors on the whole day on December 25th, 2012. Fourthly, outputs of FEM were correlated with measured stress-strain responses. After a number of trials a relationship was developed between the trial stiffness of HMA and measured mid-depth HMA temperature. At last, the obtained relationship between stiffness and temperature is verified by further FWD test when pavement temperature was recorded. A promising agreement between them is observed. Therefore, conclusion can be drawn that linear elastic FEM can accurately predict the stiffness and the structural response of flexible pavement.

Keywords: Field Instrumentation, finite element model, asphalt pavement, falling weight deflectometer test, horizontal strain, temperature probes

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1956


[1] AASHTO, Mechanistic-Empirical Pavement Design Guide, A manual of Practice, AASHTO. July 2008, Interim Edition, American Association of State Highway and Transportation Officials, Washington D. C.
[2] UddinW., and Garza S., 2010. “3D-FE Simulation Study of Structural Response Analysis for Pavement-subgrade Systems Subjected to Dynamic Loads. Pavements and Materials: Testing and Modeling in Multiple Length Scales”. ASCE, pp. 170-181.
[3] Wang J., 2001. “Three Dimensional Finite Element Analysis of Flexible Pavements”. M.S. Thesis, University of Maine, Maine, USA.
[4] Drumm E.C. and Meier R., 2003. “LTPP data analysis: Daily and seasonal variations in in-situ material properties”. Final Report, submitted to National Cooperative Highway Research Program.
[5] Orr D. P., 2005. “Seasonal variations of in situ materials properties in New York State: FWD testing and data analysis to define seasonal variability”. CLRP Report No. 05-01, Submitted to, New York State Department of Transportation.
[6] Ovik J.M., Birgisson B., and Newcomb D.E., 2000. “Characterizing seasonal variations in pavement material properties for use in a mechanistic-empirical design procedure”. Report No. MN/RC-2000-35, Submitted to Minnesota Department of Transportation, St. Paul, Minnesota 55155.
[7] Schwartz C. and Carvalho R., 2007. “Evaluation of Mechanistic- Empirical Design Procedure”. Final Report, MDSHA Project No. SP0077B41, Maryland.
[8] Islam M. R., Ahmed M. U., and Tarefder R. A., 2013. “Validation of the Backcalculated Stiffness of a Pavement Section in I-40 New Mexico”, 2nd International Conference for Sustainable Design, Engineering and Construction, ASCE, pp. 527-533.