Overview of Pavement Life Cycle Assessment Use Phase Research at the MIT Concrete Sustainability Hub (original) (raw)
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Sustainability, 2020
Recycled and low-temperature materials are promising solutions to reduce the environmental burden deriving from hot mix asphalts. Despite this, there is lack of studies focusing on the assessment of the life-cycle impacts of these promising technologies. Consequently, this study deals with the life cycle assessment (LCA) of different classes of pavement technologies, based on the use of bituminous mixes (hot mix asphalt and warm mix asphalt) with recycled materials (reclaimed asphalt pavements, crumb rubber, and waste plastics), in the pursuit of assessing energy and environmental impacts. Analysis is developed based on the ISO 14040 series. Different scenarios of pavement production, construction, and maintenance are assessed and compared to a reference case involving the use of common paving materials. For all the considered scenarios, the influence of each life-cycle phase on the overall impacts is assessed to the purpose of identifying the phases and processes which produce the greatest impacts. Results show that material production involves the highest contribution (about 60-70%) in all the examined impact categories. Further, the combined use of warm mix asphalts and recycled materials in bituminous mixtures entails lower energy consumption and environmental impacts due to a reduction of virgin bitumen and aggregate consumption, which involves a decrease in the consumption of primary energy and raw materials, and reduced impacts for disposal. LCA results demonstrate that this methodology is able to help set up strategies for eco-design in the pavement sector.
Precast Concrete Pavements of High Albedo to Achieve the Net “Zero-Emissions” Commitments
Applied Sciences, 2022
Pavements store heat, which is subsequently released into the atmosphere, heating the surrounding air. Therefore, this process contributes to climate change and global warming. For this reason, the use of high-solar-reflectance (albedo) pavements is seen as one of the potential mitigation methods for climate change. Concrete pavements have a much higher albedo than asphalt due to their light gray color compared with black pavements. Accordingly, the widespread utilization of highly reflective concrete pavements will improve local climate change mitigation. Nevertheless, concrete albedo slightly decreases over time because of weathering. Albedo and solar reflectance index (SRI) measurements were taken on actual precast concrete pavements made with different mixes. The methodology applied for this project is based on the comparison between the asphalt and concrete pavements’ reflectivity. Conventional concrete mix designs can provide cool pavements with SRI higher than 29. Replacement...
Effect of Methodological Choices on Pavement Life-Cycle Assessment
The application of life-cycle assessment (LCA) in evaluating the environmental impact of pavement systems has increased over the past two decades. The ability to quantify environmental impact over the lifespan of a pavement gives valuable insight to stakeholders in the transportation industry when making decisions about pavement planning, design, construction, and management. As a methodology, LCA is governed by a set of rules and preferences that are uniquely decided in the goal and scope of each study. Some of these choices refer to general LCA methodological elements such as those pertaining to the system boundary, cut-off criteria, or data quality requirements. Other choices are specific to the product system, such as the treatment of traffic growth or asphalt binder allocation for pavement LCA. When conducting an LCA, it is important to understand how rules and choices affect the results of the study.
Transportation Research Part D: Transport and Environment, 2014
In order to assess sustainability of products and processes, different methodologies have been developed and used in the last years. In the road pavement construction area, most methodologies used for life cycle assessment (LCA) are essentially focused in the construction phase. The present paper analyses the importance of the use phase of a road in the LCA of different paving alternatives, namely by evaluating energy consumption and gaseous emissions throughout the road pavement's life. Therefore, a new LCA methodology for road pavements was developed, and the results of its application to a case study involving the construction of alternative pavement structures are discussed. The study intends to assess the influence of using more sustainable paving construction alternatives (asphalt recycling vs. conventional asphalt mixtures), and/or different surface course materials (which have a higher influence on the rolling resistance and, therefore, affect the performance during the use phase). The LCA results obtained for this case study showed that the reductions in energy consumption and gaseous emissions obtained during the use phase, for pavement alternatives with a lower rolling resistance surface course, are higher than the total amount of energy consumption and gas emissions produced during construction. It is therefore clear that some improvements in the characteristics of the surface course may have an effect over the road use phase that will rapidly balance the initial costs and gas emissions of those interventions. The LCA results obtained also showed that the sustainability of pavement construction may also be improved using recycled asphalt mixtures.
Comparison of Life-Cycle Assessment Tools for Road Pavement Infrastructure
Transportation Research Record: Journal of the Transportation Research Board
Road pavements have considerable environmental burdens associated with their initial construction, maintenance, and usage, which have led the pavement stakeholder community to join efforts to understand and mitigate these negative effects better. Life-cycle assessment (LCA) is a versatile methodology for quantifying the effect of decisions regarding the selection of resources and processes. However, there is a considerable variety of tools for conducting pavement LCA. This paper provides the pavement stakeholder community with insights into the potential differences in the life-cycle impact assessment results of a pavement by applying American and European LCA tools, namely, PaLATE Version 2.2, the Virginia Tech Transportation Institute–University of California asphalt pavement LCA model, GaBi, DuboCalc, and ECORCE-M, to a Spanish pavement reconstruction project. Construction and maintenance life-cycle stages were considered in the comparison. On the basis of the impact assessment m...
Life Cycle Environmental Assessment Using Athena Pavement LCA Tool: A Manitoba Case Study
2016
Environmental sustainability is one of the four strategic priorities of the Department of Manitoba Infrastructure. Life Cycle Assessment (LCA) is acknowledged as one of the most comprehensive ways to evaluate the environmental impacts of different strategies associated with a physical feature. The Athena Pavement LCA software for highways is a tool that can be used to assess the environmental impacts of materials production, construction, and maintenance & rehabilitation activities over a given life cycle period. The software is also capable of modeling pavement vehicle interactions (PVI) to assess the environmental impact of traffic use phases of a roadway due to pavement surface roughness and deflection. This paper presents comparisons of the environmental impacts of various alternative strategies for a concrete pavement to demonstrate the opportunity to optimize pavement performance and environmental impacts. The concrete pavement constructed in 2015 on Manitoba Provincial Truck Highway 75 (PTH 75) has been used as a case study. A matrix of alternative concrete mix, pavement design, and maintenance and rehabilitation strategies has been used to compare environmental impacts of those alternative options. The analysis presented is expected to assist Manitoba Infrastructure and other agencies to better understand and weigh the environmental implications of alternative roadway materials, design as well as construction, maintenance and rehabilitation practices and select the best strategy considering pavement performance and preservation of our natural environment.
Increasing the sustainability of our infrastructure is accomplished in ways other than just developing better materials and using recycled materials: it is also about employing the right designs. For concrete pavements, overdesign and use of poor features causes excess materials to be used during construction, leading to higher economic costs and environmental impacts. Optimizing pavement designs for prescribed service lives, climates, and traffic conditions allows pavement engineers to create structures that have low initial costs and CO2 emissions as well as low life cycle costs and CO2 emissions. This paper shows how design optimization can lower costs and CO2 emissions by balancing: 1. The initial costs and CO2 emissions of a pavement, which are primarily a function of the thickness and specific design features used, and 2. The rehabilitation costs and CO2 emissions, which are a function of the pavement’s estimated service life and required rehabilitation activities To do this, ...
Development of life cycle assessment tool for pavement sustainability analysis
2016
Motivated by the emerging importance of sustainability in transportation infrastructure, this study aims at developing a Life Cycle Assessment (LCA) tool to quantify the energy and environmental impacts of pavements. The general LCA framework is incorporated into a highly customizable Excel-based software tool that can be used to facilitate environmental assessment of pavements at the project-level. The impact assessment focuses on the cumulative energy demand (CED) and greenhouse gas (GHG) emission in the material, construction, and maintenance phases of pavement life-cycle. LCA results are highly dependent on the quality and appropriateness of data in the life cycle inventory. Therefore, different inventory database from major pertinent studies were reviewed and summarized. To implement the LCA framework, case studies regarding runway pavement rehabilitation/reconstruction at the John F. Kennedy (JFK) airport and new runway pavement designs conducted using the Federal Aviation Adm...