A Finite Element Model for Rutting Prediction of Flexible Pavement with Cementitiously-Stabilized Base/Subbase

摘要

Cementitiously-stabilized materials (e.g., cement stabilized base/subbase, lime/fly ash stabilizedsubgrade, etc.) are widely used in roadway pavement by many state agencies. It is also a costefficientand environmental-friendly way to recycle industrial by-products. In the currentMechanistic-Empirical Pavement Design Guide (MEPDG) developed under NCHRP project 1-37A, cementitiously-stabilized layers are assumed to have no contribution to the total permanentdeformation of the pavement. Such an assumption may lead to an inadequate base thicknessdesign, especially when using a thin asphalt concrete (AC) layer or pavements subjective to aheavy traffic loading. In this study, a unified permanent deformation model developed forvarious pavement materials was used to simulate the permanent deformation behavior of thecementitiously-stabilized materials in flexible pavement. The proposed model was implementedinto the ABAQUS program through a UMAT subroutine. The finite element model wascalibrated by analyzing the permanent deformation results from six APT sections. A shift factorof 1.13 was obtained to account for the condition differences between laboratory permanentdeformation test and the field. The finite element model and the calibrated shift factor were thenused to predict the rut depths of two selected low volume roads. Good agreement was foundbetween the predicted and measured data.