“On the Road to Sustainable Pavement Management: a Life Cycle Assessment Framework for Pavement Maintenance and Rehabilitation Facing Uncertainty”

Andrea Vargas Farias*; Joao Santos; Andreas Hartmann Engineeringandtechnology|CivilEngineeringandManagement|ConstructionManagementandEngineering| UniversityofTwente,Netherlands

Introduction

• Road pavements go through numerous maintenance and rehabilitation (M&R) cycles over their lifetime, each of which generate significant environmental impacts due to production, construction, use and end-of-life.

• Life-cycle assessment (LCA) allows us to account for the impacts of M&R cycles throughout their entire life-cycle but faces important challenges related to the suitability of the underlying LCA framework for M&R, and the lack of consideration of uncertainties in the analysis.

Research questions

• How can the environmental performance of road pavement M&R be assessed under uncertainty?

1. What are the LCA considerations that should be included in the assessment of the environmental impacts of the M&R of road pavements?

2. What are the primary sources of uncertainty in the LCA calculation of the environmental impacts of the M&R of road pavements and how can they be handled?

M&R measures and cases

• 75 different life extending (LEM) and major (MM) M&R applied to the main Dutch road network.

• Four different M&R asphalt overlay cases:

1. Surface layer addition,

2. Surface layer replacement,

3. Surface layer replacement + binder layer addition

4. Surface and binder layer replacement.

Design of LCA framework for M&R

• Five general life-cycle phases for M&R (Figure2) with different applicability for each M&R case.

• Incorporation of pavement-vehicle interaction effects to the use module to account for the extra fuel consumption due to an increase in pavement rolling resistance over time.

Uncertainty analysis

• Design of an uncertainty analysis methodology (Figure3):

• Characterization and propagation of the uncertainty of multiple input parameters and different methodological choices to the LCA results.

• Performance of a global sensitivity analysis to identify the inputs with the largest contributions to the uncertainty in the results.

Organizing project-transcending collaborations in infrastructure

Societalchallenges;Innovation;Programmaticcollaboration;Ecosystems;InfrastructureManagement; Public-privatecollaboration

Lynn Vosman* & Leentje Volker | University of Twente, Netherlands

Fleur Deken | VU Amsterdam

Introduction

Programmatic collaboration in infrastructure is a promising approach to increase the efficiency of project practices, to stimulate innovation and to contribute to overarching sustainable development goals such as circularity and urban resilience In this approach, individual assets are clustered under long-term, performance-based programmes These programmes are executed by one or several contractors and other suppliers for a period of time that transcends the single-project duration. Another step towards more efficient contribution to the major societal challenges ahead is the development of infrastructure ecosystems. Since no single organization is able to tackle these challenges alone, the formation of strategic collaborations in networks is necessary. Ecosystems are heterogeneous networks of actors centred around a value proposition, where the essence lays in the exploration of actor’s complementary values and potential contributions Every actor involved contributes a ‘piece of the puzzle’ in pursuing the shared value proposition This research investigates the concept of programmatic collaboration and ecosystems in the infrastructure sector

Research approach

The aim of this research is to increase scientific and practical knowledge on the transition from a project-based way of working towards programmatic collaboration in project-transcending networks. It is inspired by ecosystems thinking, and is based on a qualitative and engaged scholarly approach, conducted by a strategic research partnership between the University of Twente and the Vrije Universiteit Amsterdam in the Netherlands. The central questions are: how do we align and co-ordinate the interests of actors in infrastructure, and how does working in long-term programmes impact existing (industrial) structures, routines, and roles? The expected results will contribute to the insight we have in how networks of actors in the infrastructure sector can be re-arranged in a way that transcends individual projects And also, the findings will help understand the challenges these interorganisational, public-private networks face in the transition to ecosystems that will deliver reliable services to public infrastructure.

Engaged scholarship

The research team consists of ir Lynn Vosman (UT), Prof. Dr ir Leentje Volker (UT) and Dr ir Fleur Deken (VU Amsterdam). The research is funded by six public client organizations from the Dutch Infrastructure Sector (see below), and planned for 5 years from the beginning of 2021.