Development of Finite Element Models to study Pavement Widening

Abstract

Sustainability has become a paramount concern in modern research, aligning with global efforts to reduce carbon emissions and embrace circular economy principles. The mentioned imperative extends to the field of pavement engineering, where the widening of existing pavements, a common practice to accommodate increasing traffic demands, necessitates sustainable solutions. The current thesis addresses the pressing need for pavement engineering practices that align with ambitious sustainability goals while ensuring structural integrity and performance.

Drawing upon the context of countries like the Netherlands, striving for zero carbon emissions and full circularity by 2030, the research explores avenues for sustainable pavement widening. This involves optimizing designs to minimize material usage, reduce emissions, incorporate recyclable materials, and extend the lifespan of road infrastructure. The challenges posed by non-uniform settlements and stress concentrations at widening joints are investigated, highlighting the importance of accurate material modelling and interface characterization.

Motivated by the need for sustainable pavement solutions, the research aims to guide decision-making in pavement design towards environmental sustainability while meeting functional requirements. The scope encompasses FEM models, EVP behaviour of asphalt surfaces, base layer variations, interface modelling, and comparative analyses between 2D and 3D models.

The current study undertakes a thorough examination of the implications of pavement widening on stress concentrations, material behaviour, and interface modelling, aiming for development of more sustainable and resilient pavement designs. Employing a comprehensive research framework encompassing theoretical modelling and numerical simulations, the study seeks to elucidate the issues inherent in widened pavement structures.

The main thesis objective is the development of an elasto-visco-plastic (EVP) material model, to capture the time-dependent behaviour exhibited by asphalt surfaces under varying loading conditions. Using the Finite Element Method (FEM), the developed material model serves as a foundational pillar for subsequent investigations, facilitating an examination of stress distribution patterns within widened pavement structures.

The Research provides a detailed framework for conducting the study on pavement widenings. It begins with the delineation of study parameters, including cross-sectional geometry, material properties, and simulation techniques. The development and validation of the EVP material model are elaborated, along with the implementation of finite element method (FEM) simulations to analyse stress distributions. Parametric analyses are conducted to investigate the effects of load variations, base layer characteristics, and interface modelling on widened pavement performance. The methodology also includes the utilization of cohesive zone modelling for interface characterization, enabling a more detailed representation of pavement layer interfaces.

The identification of critical stress concentrations emerges as a focal point of inquiry, necessitating a crucial to understand the interplay between load variations, base layer thickness, and material stiffness. Through various numerical analyses, the study seeks to unravel the intricate web of factors influencing stress propagation within widened pavement structures. Moreover, the implications of reduced recessing length and base layers in new pavement designs are subjected to meticulous scrutiny, shedding light on potential trade-offs between structural integrity and resource optimization.


Overall, the current thesis contributes to advancing pavement engineering practices, promoting sustainable transportation infrastructure, and supporting global sustainability goals. Through rigorous analysis and modelling, the research seeks to enhance the understanding of critical factors influencing widened pavement performance, paving the way for safer, more efficient, and environmentally conscious road networks.