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Analysis on Relationship between FWD Back-calculated Modulus and Dynamic Modulus of Asphalt Layers for Existing Asphalt Pavements

공용중인 아스팔트 포장의 아스팔트층 동탄성계수와 FWD 역산 탄성계수의 상관관계 분석

  • Received : 2015.08.12
  • Accepted : 2015.10.01
  • Published : 2015.10.15

Abstract

PURPOSES: The objective of this study is to analyze the relationship between the FWD back-calculated modulus and dynamic modulus of asphalt layers for existing asphalt pavements. METHODS: To evaluate the dynamic modulus of the asphalt mixture in the existing and new asphalt layers, the uniaxial direct tension test was conducted on small asphalt specimens obtained from the existing asphalt-covered pavements. A dynamic modulus master curve was estimated by using the uniaxial direct tension test for each asphalt layer. The falling weight deflectometer (FWD) testing was conducted on the test sections, and the modulus values of pavement layers were back-calculated using the genetic algorithm and the finite element method based back-calculation program. The relationship between measured and back-calculated asphalt layer moduli was examined in this study. The normalized dynamic modulus was adopted to predict the stiffness characteristics of asphalt layers more accurately. RESULTS: From this study, we can conclude that there is no close relationship between dynamic modulus of first layer and back-calculated asphalt modulus. The dynamic moduli of second and third asphalt layers have some relation with asphalt stiffness. Test results also showed that the normalized dynamic modulus of the asphalt mixture is closely related to the FWD back-calculated modulus with 0.73 of R square value. CONCLUSIONS: The back-calculated modulus of asphalt layer can be used as an indicator of the stiffness characteristics of asphalt layers in the asphalt-covered pavements.

Keywords

References

  1. Kutay, M. E., N. H. Gibson, J. Youtcheff, and R. Dongre. (2009) Use of Small Samples to Predict Fatigue Lives of Field Cores:Newly Developed Formulation Based on Viscoelastic Continuum Damage Theory. Transportation Research Record:Journal of the Transportation Research Board, No. 2127, National Research Council, Washington, D.C., pp. 90-97.
  2. NHI.(1994) NHI Course No. 137, "Pavement Deflection Analysis - Participant Workbook", FHWA-HI-94-021, FHWA, U.S. Department of Transportation.
  3. Park H.J. and Y. R. Kim (2013), "Investigation into Top-Down Cracking of Asphalt Pavements in North Carolina", Transportation Research Record 2368, National Research Council, Washington D.C., PP.45-55.
  4. Park, H.M., Kim, Y.R. and Park, S.W (2005) "Assessment of pavement layer condition with use of multiload-level falling weight deflectometer deflections", In Transportation Research Record 1905, TRB, National Research Council, Washington D.C., pp. 107-116.
  5. Park, S. W., H. M. Park, and J. J. Hwang (2007), "Development of a Backcalculation Method for Estimating Pavement Layer Modulus Using the Genetic Algorithm", Korean Society of Civil Engineers, Vol 27, pp.441-447.
  6. Son, J. C., S. K. Rhee, D. S. An, and H. M. Park (2006), "Development of the Structural Condition Evaluation Technique for Asphalt Pavements Using Falling Weight Deflectometer Deflections", International Journal of Highway Engineering, Korean Society of Road Engineers, Vol 8/3 , pp.1-19.
  7. Ullidtz, P. and Coetzee, N.F. (1995) "Analytical Procedures in Nondestructive Testing Pavement Evaluation", In Transportation Research Record 1482, TRB, National Research Council, Washington D.C., pp. 61-66.