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Development of comprehensive deflection parameters to evaluate the structural capacity of flexible pavements at the network level


Pavement deflection has been used widely as a nondestructive technique to evaluate the structural capacity of pavements at both network and project levels. Current devices include Falling Weight Deflectometer (FWD) and the Deflectograph, which can record the deflection bowl shape. Utilizing these devices, a load is applied on the pavement surface and deflections at several lateral locations are recorded. Various transportation agencies use several evaluation methods to evaluate the integrity of the pavement layers. Most of these up-to-date developed indices are exclusively based on either central deflections or one deflection point along FWD deflection bowl. However, no standardized method is available that utilizes the full FWD deflection bowl.

This study aims to introduce new comprehensive pavement layer deflection and deflection bowl area parameters that are based on the entire FWD deflection bowl rather than one single deflection point and to relate the developed parameters to the field measured distress data. Required data for the study were extracted from the Long-Term Pavement Performance (LTPP) database.

Thirty-five different pavement sections in the State of Texas were utilized in the study. Four comprehensive deflection parameters were developed. In addition, a scale was developed that may be utilized for the overall pavement structural condition evaluation. The developed parameters as well as the scale were found to be well correlated to field performance of considered pavement sections. The newly developed parameters can also be easily implemented in pavement management databases (PMS) that would help state department of transportation (DOTs) in making more informed decisions about the most suitable maintenance strategy.

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  1. G. R. Rada, S. Nazarian, J. Daleiden, T. Yu, Moving pavement deflection testing devices: State-of-the-technology and best uses, Paper ICMPA082, 8th International Conference on Managing Pavement Assets, Chile, 2011.

    Google Scholar 

  2. P. N. Schmalzer, Long-term pavement performance program manual for falling weight deflectometer measurements. No. FHWA-HRT-06-132. Federal Highway Administration. Office of Infrastructure Research and Development, United States, 2006.

    Google Scholar 

  3. R. Haas, W. R. Hudson, J. P. Zaniewski, Modern pavement management, Krieger Press, Malamar, Florida, 1994.

    Google Scholar 

  4. T. Scullion, Incorporating a Structural Strength Index into the Texas Pavement Evaluation System, Research Report 409 — 3F, Texas Transportation Institute, 1988.

    Google Scholar 

  5. D. S. Gedafa, M. Hossain, R. Miller, T. Van, Estimation of remaining service life of flexible pavements from surface deflections, J. Transp. Eng. 136 (4) (2010) 342–352.

    Article  Google Scholar 

  6. O. Elbagalati, M. A. Elseifi, K. Gaspard, Z. Zhang, Prediction of In-Service Pavement Structural-Capacity Based on Traffic-Speed Deflection Measurements, J. Transp. Eng. 142 (11) (2016) 04016058.

    Article  Google Scholar 

  7. M. Saleh, Simplified Approach for Structural Capacity Evaluation of Flexible Pavements at the Network Level, Inter. J. Pave. Eng. 17 (5) (2016) 440–448.

    Article  Google Scholar 

  8. M. Saleh, Utilisation of the Deflectograph Data to Evaluate Pavement Structural Condition of the Highway Network, Road Mater. Pave. Des. 17 (1) (2016) 136–152.

    Article  Google Scholar 

  9. M. Saleh, A mechanistic empirical approach for the evaluation of the structural capacity and remaining service life of flexible pavements at the network level, Canad. J. Civ. Eng. 43 (8) (2016) 749–758.

    Article  Google Scholar 

  10. E. Horak, S. Emery, Falling Weight Deflectometer Bowl Parameters as Analysis Tool for Pavement Structural Evaluations, Proceedings, 22nd Australian Road Research Board (ARRB) International conference, Brisbane, Australia, 2006.

    Google Scholar 

  11. H. Yin, Simulation of flexible pavement response to FWD loads: A mechanistic approach, Inter. J. Pave. Res. Technol. 5 (4) (2012) 257–66.

    MathSciNet  Google Scholar 

  12. J. S. Miller, W. Y. Bellinger, Distress Identification Manual for the LongTerm Pavement Performance Program. FHWA-HRT-13-092, USDOT, 2014.

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The authors pay due credit and gratefully thanks US Department of Transportation (USDOT) and the Transportation Consortium of South-Central States (Tran-SET) for funding this research study.

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Correspondence to Mena I. Souliman.

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Peer review under responsibility of Chinese Society of Pavement Engineering.

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Loganathan, K., Isied, M.M., Coca, A.M. et al. Development of comprehensive deflection parameters to evaluate the structural capacity of flexible pavements at the network level. Int. J. Pavement Res. Technol. 12, 347–355 (2019).

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  • Flexible pavement sections
  • Deflection
  • Deflection bowl
  • FWD