Prediction Analysis of CTB Asphalt Pavement Moduli Based on FWD Deflection Data

Abstract

Layers moduli are very crucial parameters for pavement design and evaluation with a mechanistic-empirical method. Falling Weight Deflectometer (FWD), as a nondestructive testing technology, is an effective tool to determine asphalt pavement layer moduli. The objective of this study was to establish a method to predict structural layer moduli of cement treated base (CTB) asphalt pavements by using FWD deflection basin parameter (DBP) indicators. Firstly, a general dynamic finite element model of CTB asphalt pavements was established and a synthetic database of dynamic DBP indicators corresponding with material properties of structural layers was generated. Secondly, the relationship between DBP indicators and structural layer moduli was discussed by the related coefficient, then the optimal regression function was established to predict structural layer moduli. Finally, the presented method was applied to predict structural layer moduli of the existing CTB asphalt pavement of Shanghai A11 Expressway and its validity was verified by the fitting degree between the measured deflection basin and the theoretical deflection basin. The research results provide a technology supports to popularize FWD testing technology applied in evaluating structural performance of CTB asphalt pavements.