A mechanistic–empirical model for base-reinforced flexible pavements

TLDR

The model builds on traditional components of an existing unreinforced mechanistic–empirical pavement model developed under NCHRP Project 1‑37A. The study proposes a mechanistic–empirical model for geosynthetic base‑reinforced flexible pavements and describes its components with an emphasis on predicting permanent deformation. It integrates a finite‑element response model, material models for asphalt concrete, unbound aggregate base, subgrade, and damage models for fatigue cracking and permanent deformation, and adds reinforcement‑specific elements such as structural reinforcement models, reinforcement–aggregate shear interaction, lateral confinement effects, and a modified permanent deformation damage model for the reinforcement influence zone. Comparison with test sections shows favourable agreement comparable to unreinforced models and a substantial improvement over earlier reinforced pavement models.

Abstract

A mechanistic–empirical model for geosynthetic base-reinforced flexible pavements is proposed. The model uses traditional components of an existing unreinforced mechanistic–empirical model developed in the USA through NCHRP Project 1-37A. These components include a finite element response model, material models for the asphalt concrete, unbound aggregate base and subgrade and damage models for asphalt concrete fatigue cracking and permanent deformation in the pavement cross-section layers. New components for the reinforcement are introduced and include structural elements for the reinforcement, a material model for the reinforcement, a model for reinforcement–aggregate shear interaction, additional response modelling steps that account for the influence of the reinforcement on lateral confinement of the base aggregate during construction and subsequent traffic loading, and a modified permanent deformation damage model used for aggregate within the influence zone of the reinforcement. This paper describes the basic components of the model with a focus on the ability of the model to predict permanent deformation, which is compared to results from test sections. This comparison shows favourable agreement that is on the level seen with existing unreinforced mechanistic–empirical models and a large improvement over previously proposed models for reinforced pavements.