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Joao Santos - One of the best experts on this subject based on the ideXlab platform.
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climate change impacts on asphalt road Pavement construction and maintenance an economic Life Cycle assessment of adaptation measures in the state of virginia united states
Journal of Industrial Ecology, 2020Co-Authors: Yaning Qiao, Joao Santos, Anne M K Stoner, Gerardo W FlinstchAbstract:Pavement design and management practices must be adapted in response to future climate change. While many studies have attempted to identify different methods to adapt Pavements to future climate conditions, the potential economic impacts of the adaptations still remain largely unquantified. This study presents the results of a comprehensive Life-Cycle cost analysis (LCCA) aimed at quantifying the potential economic impacts of a climate adaptation method, in which an upgraded asphalt binder (Performance Grade PG 76-22) is used in the construction and maintenance of flexible Pavement sections in lieu of the original binder (PG 70-22) for improved resistance against high temperatures. For each of three major Virginia Department of Transportation (VDOT) districts with different climates, three case studies consisting of typical interstate, primary, and secondary Pavement sections were considered. The LCCA accounted for the costs incurred during the mixture's production, maintenance, and use phases of the Pavement Life Cycle by explicitly considering future climate projections, Pavement Life-Cycle performance, maintenance effects, and work zone user delays. The study concludes that Pavements using the upgraded binder not only perform better over time but are also economically advantageous compared to those with the original binder under the conditions of the anticipated future climate conditions (2020–2039).
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Life Cycle assessment of low temperature asphalt mixtures for road Pavement surfaces a comparative analysis
Resources Conservation and Recycling, 2018Co-Authors: Joao Santos, Véronique Cerezo, Davide Lo Presti, Sara Bressi, Michel DauvergneAbstract:Abstract The increasing fuel consumption demand, the accelerated pressure imposed by the depletion of scarce raw materials and the urgent environmental protection requirements are forcing the change of Pavement industry and academia community’s research endeavours towards the development of low emissions road paving technologies able to significantly reduce mixing and compaction temperature as well as the consumption of virgin raw materials. One of the relatively recent technologies in the field of Pavement materials that aims at addressing those concerns is the incorporation of reclaimed asphalt Pavement (RAP) in the production of warm mix asphalt (WMA). It is within this context that this study presents a full process-based comparative Life Cycle assessment (LCA) looking at understanding the environmental impact of reducing mixing temperature, through the use of warm mix technologies, namely chemical additives-based and foamed-based, and different rate of recycling (0% and 50% RAP). Furthermore, the investigation explores the effect of combining these technologies in the construction, maintenance and rehabilitation (M&R) of wearing courses for flexible road Pavements. The results of this study showed that, for the conditions considered and assumptions performed, a Pavement construction and M&R scenario in which a foamed-based WMA mixture with a RAP content of 50% is employed in the wearing course throughout the Pavement Life Cycle is the most environmentally friendly alternative among all the competing solutions.
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a comparative Life Cycle assessment of hot mixes asphalt containing bituminous binder modified with waste and virgin polymers
Procedia CIRP, 2018Co-Authors: Joao Santos, Khedoudja Soudani, Véronique Cerezo, Sara EssiAbstract:Abstract This paper presents the results of a Life Cycle assessment undertaken to compare the potential environmental impacts associated with the use of asphalt surface mixtures produced with polymer modified bitumen with those of a conventional asphalt surface mixture. Seven types of hot mix asphalt mixtures to be used in the surface course are compared, among which one produced with virgin materials and conventional binder, which is used as a reference, and six alternative mixtures containing a bituminous binder modified with different percentages of waste nitrile rubber from shoe sole and Ethylene-Vinyl-Acetate polymer. The ILCD impact assessment method at midpoint level was adopted to assess the environmental performance of the wearing course of a French Pavement structure over a 30-year project analysis period considering the following Pavement Life Cycle phases: (1) extraction of raw materials, modification of the bituminous binder and mixtures production; (2) transportation of materials, and; (3) construction and maintenance and rehabilitation.
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a multi objective optimization based Pavement management decision support system for enhancing Pavement sustainability
Journal of Cleaner Production, 2017Co-Authors: Joao Santos, Adelino Ferreira, Gerardo W FlintschAbstract:Abstract Current practice adopted by highway agencies with regards to Pavement management, has mostly consisted of employing Life Cycle costs analysis (LCCA) systems to evaluate the overall long-term economic efficiency of competing Pavement design and maintenance and rehabilitation (MR (2) a comprehensive and integrated Pavement Life Cycle costs - Life Cycle assessment (LCC-LCA) module that covers the whole Life Cycle of the Pavement; and (3) a decision-support module. The potential of the proposed DSS is illustrated with one case study consisting of determining the optimal MR (2) minimization of the PV of the Life Cycle road user costs (LCRUC); and (3) minimization of the Life Cycle greenhouse gas emissions (LCGHG). In comparison to the traditional maintenance strategy, the proposed DSS suggests a maintenance plan that reduces LCHAC by 15%, LCRUC by 28% and LCGHG by 26%.
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a comprehensive Life Cycle costs analysis of in place recycling and conventional Pavement construction and maintenance practices
International Journal of Pavement Engineering, 2017Co-Authors: Joao Santos, James Bryce, Gerardo W Flintsch, Adelino FerreiraAbstract:AbstractRecent studies based on Life Cycle Assessment (LCA) have highlighted the potential of in-place recycling techniques to enhance the sustainability of agency Pavement management decisions for asphalt Pavements. However, a solution which an LCA finds environmentally advantageous might not be preferred over another which is technically equivalent, if it is not economically competitive. In this context, it is necessary to evaluate the economic costs of such alternatives taking into account the perspective of the main stakeholders who interact with a Pavement system throughout its Life Cycle. This paper presents a comprehensive Pavement Life Cycle costs (LCC) model that accounts for the different categories of costs incurred by highway agencies and road users in every phase of the Pavement Life Cycle. The results of the application of the Pavement LCC model to a specific highway rehabilitation project in the state of Virginia showed that in-place recycling practices are beneficial for both highway agenc...
Nicholas J Santero - One of the best experts on this subject based on the ideXlab platform.
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greenhouse gas emissions reduction opportunities for concrete Pavements
Journal of Industrial Ecology, 2013Co-Authors: Nicholas J Santero, Alexander Loijos, John OchsendorfAbstract:Concrete Pavements are a vital part of the transportation infrastructure, comprising nearly 25% of the interstate network in the United States. With transportation authorities and industry organizations increasingly seeking out methods to reduce their carbon footprint, there is a need to identify and quantitatively evaluate the greenhouse gas (GHG) emission reduction opportunities that exist in the concrete Pavement Life Cycle. A select few of these opportunities are explored in this article in order to represent possible reduction approaches and their associated cost-effectiveness: reducing embodied emissions by increasing fly ash content and by avoiding overdesign; increasing albedo by using white aggregates; increasing carbonation by temporarily stockpiling reCycled concrete aggregates; and reducing vehicle fuel consumption by adding an extra rehabilitation. These reduction strategies are evaluated for interstate, arterial, collector, and local road designs under urban and rural scenarios. The results indicate that significant GHG emission reductions are possible, with over half of the scenarios resulting in 10% reductions, compared to unimproved baseline designs. Given the right conditions, each scenario has the potential to reduce GHG emissions at costs comparable to the current price of carbon.
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Life Cycle climate impacts of the us concrete Pavement network
Resources Conservation and Recycling, 2013Co-Authors: Alexander Loijos, Nicholas J Santero, John OchsendorfAbstract:Life Cycle assessment (LCA) offers a comprehensive approach to evaluate and improve the environmental impacts of Pavements. First, a general Pavement LCA methodology is created that describes the concepts necessary to conduct a comprehensive Pavement LCA. Second, the methodology is applied to the Life Cycle of concrete Pavements to quantify current emissions across the road network. System boundaries are drawn to include all phases of the Pavement Life Cycle – materials production, construction, use, maintenance, and end of Life. Greenhouse gas emissions are quantified for twelve functional units, which evaluate average conditions for each major roadway classification in the United States. The results present the relative contribution of each component in the Life Cycle, the annual emissions occurring during the 40-year analysis period, and the sensitivity of these results to model parameters. It is found for all roads that the majority of emissions occur in year one – from cradle-to-gate materials production, and Pavement construction – primarily due to cement production. The results are most sensitive to traffic volume, and then to parameters affecting the cement production. Based on emissions and their sensitivity, the LCA results suggest three broad reduction approaches: reducing embodied emissions, reducing use phase emissions, and reducing end-of-Life emissions.
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Pavement Life Cycle assessment workshop may 5 7 2010 in davis california usa
International Journal of Life Cycle Assessment, 2011Co-Authors: J Harvey, Alissa Kendall, Nicholas J Santero, Thomas J Van Dam, I S Lee, Ting WangAbstract:Purpose A workshop was convened on Life Cycle assessment (LCA) applied to Pavement. The workshop’s primary goals were to establish common practices for conducting LCAs for Pavements. In general, Pavement LCA has been implemented without clear guidelines for modeling assumptions and reporting. This shortcoming has led to challenges in interpreting and comparing Pavement LCA outcomes.
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Methods, Impacts, and Opportunities in the Concrete Pavement Life Cycle
2011Co-Authors: Nicholas J Santero, Alexander Loijos, Mehdi Akbarian, John OchsendorfAbstract:MIT Concrete Sustainability Hub research is supported by the Portland Cement Association and the Ready Mixed Concrete Research and Education Foundation.
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Life Cycle assessment of Pavements part i critical review
Resources Conservation and Recycling, 2011Co-Authors: Nicholas J Santero, Eric Masanet, Arpad HorvathAbstract:The rapidly expanding set of Pavement Life-Cycle assessments (LCAs) available in the literature represents the growing interest in improving the sustainability of this critical infrastructure system. The existing literature establishes a foundational framework for quantifying environmental impact, but fails to deliver global conclusions regarding materials choices, maintenance strategies, design lives, and other best-practice policies for achieving sustainability goals. In order to comprehensively quantify environmental footprints and effectively guide sustainability efforts, functional units need to be standardized, systems boundaries expanded, data quality and reliability improved, and study scopes broadened. Improving these deficiencies will allow future studies to perform equitable and comparable assessments, thus creating a synergistic set of literature that continuously builds upon itself rather than generates independent and isolated conclusions. These improvements will place the body of Pavement LCA research in a better position to confidently lead private industry and government agencies on successful paths towards sustainability goals.
Susan L Tighe - One of the best experts on this subject based on the ideXlab platform.
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preventing foreign object debris and improving Pavement Life Cycle costs through effective fast track concrete repair
Transportation Research Board 86th Annual MeetingTransportation Research Board, 2007Co-Authors: James Trevor Smith, Susan L TigheAbstract:The biggest challenge facing airports, is the need to ensure efficient operations including proper maintenance of the airfield Pavements (i.e. runways, taxiways and aprons). In short, the study presents a methodology of assessing repair materials in terms of technical and economic factors. This research identifies economical fast track concrete material and construction methods suitable for partial depth repairs in the airport environment. Specifically, the research in this paper is directed at addressing various technical and economic concerns regarding the use of fast track concrete with harsh deicing chemicals and extreme weather conditions. It describes a field study which is located at Canada’s largest airport and North America’s fifth busiest airport. Seven test sections were repaired on Deicing Bay 2 at Toronto International Airport with three different fast track products. Fourteen Pavement evaluations were completed between October 20, 2003 and June 2, 2006. Test section performance was evaluated using the Strategic Highway Research Project H-356 method. The Foreign Object Damage average values on June 2, 2006 were calculated as 19 for Product A, 20 for Product B, and 40 for Product C. The Product A test sections are performing the best and is the product of choice. Based on the developed linear regression models, test section 7 which is Product C will last the longest before MR&R activities are required. This was followed by Product A and then Product B. However, the difference between Product C and Product A was not statistically significant. Life Cycle cost analysis showed that using a fast track partial depth high quality repair product was more cost effective than other types of repair.
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incorporating variability into Pavement performance Life Cycle cost analysis and performance based specification pay factors
Transportation Research Record, 2005Co-Authors: Leanne Whiteley, Susan L Tighe, Zhanmin ZhangAbstract:This paper describes a recent research study that examined how changes in design Life affected the Pavement Life-Cycle cost and ultimately how the reduction in or addition to Life-Cycle cost attributed to superior or inferior in-service performance could be used as a basis for establishing a pay factor for a performance-based specification. Previous models were developed with data from the Canadian Long-Term Pavement Performance Program, which indicated that overlay thickness, total prior cracking, annual freezing index, annual days with precipitation, and accumulated equivalent single-axle loads (ESALs) after 8 years affected the slope of Pavement deterioration for asphalt overlay Pavements. One of these models, as well as data from the U.S. Long-Term Pavement Performance test sites, is used to determine the service Life of asphalt overlay Pavements. This paper examines how the variability associated with overlay thickness, total prior cracking, and accumulated ESALs after 8 years affects the service Life of asphalt overlay Pavements. Furthermore, this paper considers the variability associated with the discount rate and incorporates all associated variability into the Life-Cycle cost analysis (LCCA). LCCA is performed by using Monte Carlo techniques. On the basis of a recent study, distributions for service Life and Life-Cycle costs are developed by using both normal and lognormal distributions for overlay thickness. With the LCCA values for typical design lives, a sensitivity analysis is subsequently performed to evaluate the impact of 10%, 20%, and 30% differences in the in-service performance as compared to the design Life. These LCCA differences are then used as a basis for establishing pay factors. Overall the paper attempts to relate design to in-service performance Life-Cycle cost and the ultimate use of pay factors.
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guidelines for probabilistic Pavement Life Cycle cost analysis
Transportation Research Record, 2001Co-Authors: Susan L TigheAbstract:To select the most appropriate Pavement design for a given situation, it is necessary to understand how the Pavement properties and in-service conditions relate to performance and Life Cycle cost. A given design may be most appropriate on one type of road and least appropriate on another type of road. This design selection is further complicated by the advent of new design methodologies, materials, and construction delivery techniques. Life Cycle economic analysis is an important tool for comparing alternative treatment strategies. A Life Cycle analysis can use a deterministic approach, which incorporates a single point value, or it can use a probabilistic approach, which includes a mean, variance, and probability distribution. The probabilistic approach is better suited to describing the uncertainty associated with engineering. The Canadian Strategic Highway Research Program Canadian Long-Term Pavement Performance database and data provided by the Ministry of Transportation of Ontario were used in this analysis. Most construction variables are generally believed to be best described by a normal distribution. However, a lognormal probability distribution is better suited to describing these variables. This best fit is based on both a mathematical examination and a comparison of similar variables such as stocks and real estate values. It is also shown that thickness is a probabilistic variable that should be combined with the cost and incorporated into Pavement Life Cycle costing. Ignoring the lognormal nature of these variables introduces bias into a Life Cycle cost analysis and does not reflect the true overall cost.
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Allocation of Pavement damage due to trucks using a marginal cost method
TRANSPORTATION RESEARCH RECORD, 1998Co-Authors: Jerry J Hajek, Susan L Tighe, B. G. HutchinsonAbstract:A procedure was developed for quantifying the Pavement cost of proposed changes in regulations governing truck weights and dimensions, particularly the marginal cost method used for Pavement cost allocation. The procedure was part of a comprehensive study undertaken by the Ontario Ministry of Transportation in response to government and indus try initiatives to harmonize Ontario's truck regulations with those in surrounding jurisdictions. The marginal Pavement cost of truck damage was defined as a unit cost of providing Pavement structure for one additional passage of a unit truckload (expressed as equivalent single axle load). The results indicate that the highway type (or truck volumes associated with the highway type) has a major influence on marginal costs. For example, the annualized Pavement Life-Cycle cost of the passage of one additional typical truck on 1 km of a highway in southern Ontario can range from about $0.004 for a freeway to $0.46 for a local road (Canadian dollars). The marginal cost method can be used to quantify Pavement damage due to any axle load combination for both new and existing, in-service Pavements. The knowledge of marginal costs would enable highway agencies to quantify the impact of specific regulatory changes of truck axle weights on Pavement costs; for example, to quantify the Pavement costs associated with increasing allowable truck weights of logging trucks on a specific segment of the highway network.
Gerardo W Flintsch - One of the best experts on this subject based on the ideXlab platform.
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a multi objective optimization based Pavement management decision support system for enhancing Pavement sustainability
Journal of Cleaner Production, 2017Co-Authors: Joao Santos, Adelino Ferreira, Gerardo W FlintschAbstract:Abstract Current practice adopted by highway agencies with regards to Pavement management, has mostly consisted of employing Life Cycle costs analysis (LCCA) systems to evaluate the overall long-term economic efficiency of competing Pavement design and maintenance and rehabilitation (MR (2) a comprehensive and integrated Pavement Life Cycle costs - Life Cycle assessment (LCC-LCA) module that covers the whole Life Cycle of the Pavement; and (3) a decision-support module. The potential of the proposed DSS is illustrated with one case study consisting of determining the optimal MR (2) minimization of the PV of the Life Cycle road user costs (LCRUC); and (3) minimization of the Life Cycle greenhouse gas emissions (LCGHG). In comparison to the traditional maintenance strategy, the proposed DSS suggests a maintenance plan that reduces LCHAC by 15%, LCRUC by 28% and LCGHG by 26%.
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a comprehensive Life Cycle costs analysis of in place recycling and conventional Pavement construction and maintenance practices
International Journal of Pavement Engineering, 2017Co-Authors: Joao Santos, James Bryce, Gerardo W Flintsch, Adelino FerreiraAbstract:AbstractRecent studies based on Life Cycle Assessment (LCA) have highlighted the potential of in-place recycling techniques to enhance the sustainability of agency Pavement management decisions for asphalt Pavements. However, a solution which an LCA finds environmentally advantageous might not be preferred over another which is technically equivalent, if it is not economically competitive. In this context, it is necessary to evaluate the economic costs of such alternatives taking into account the perspective of the main stakeholders who interact with a Pavement system throughout its Life Cycle. This paper presents a comprehensive Pavement Life Cycle costs (LCC) model that accounts for the different categories of costs incurred by highway agencies and road users in every phase of the Pavement Life Cycle. The results of the application of the Pavement LCC model to a specific highway rehabilitation project in the state of Virginia showed that in-place recycling practices are beneficial for both highway agenc...
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a Life Cycle assessment of in place recycling and conventional Pavement construction and maintenance practices
Structure and Infrastructure Engineering, 2015Co-Authors: Joao Santos, James Bryce, Adelino Ferreira, Gerardo W Flintsch, Brian K DiefenderferAbstract:The application of in-place recycling techniques has emerged as a practical and effective way to enhance the sustainability of agency Pavement management decisions for asphalt-surfaced Pavements. However, the potential environmental benefits resulting from applying in-place recycling techniques have not been fully documented in the literature. This paper presents a comprehensive Pavement Life Cycle assessment (LCA) model that extends the typical Pavement LCA's system boundaries to include the environmental impacts resulting from the usage phase and the production of the energy sources. The results of the application of the Pavement LCA model to a specific highway rehabilitation project in the state of Virginia showed that in-place recycling practices and an effective control of the Pavement roughness can improve significantly the Life Cycle environmental performance of a Pavement system.
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a Life Cycle assessment model for Pavement management road Pavement construction and management in portugal
International Journal of Pavement Engineering, 2015Co-Authors: Joao Santos, Adelino Ferreira, Gerardo W FlintschAbstract:Improving the sustainability of road Pavements requires road agencies and construction companies to identify, by means of appropriate methodologies and tools, the priority areas of action. The Life Cycle assessment method has gradually become a versatile tool capable of informing decisions on resource and process selection to better understand, measure and reduce the environmental impacts of a system. This article presents the results of a study aimed at estimating and comparing the Life Cycle impacts of the flexible Pavement structures defined in the Portuguese Pavement design catalogue. The analysis assessed the functional units over a 40-year project analysis period (PAP), considering all Pavement Life Cycle phases: extraction of raw materials and production; transportation of materials; construction, maintenance and rehabilitation; work zone traffic management; usage and end-of-Life. The results of the case study showed that for the less demanding traffic classes the materials phase is the main contri...
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a Life Cycle assessment model for Pavement management methodology and computational framework
International Journal of Pavement Engineering, 2015Co-Authors: Joao Santos, A J M Ferreira, Gerardo W FlintschAbstract:Despite the general consensus among stakeholders on how useful the Life Cycle assessment (LCA) methodology can be in helping to reduce the environmental burdens of a road Pavement, very few Pavement LCA models have considered the entire Pavement Life Cycle. This paper presents the development of a highly customisable LCA tool that provides an integrated, project-level approach that includes all six Pavement Life Cycle phases. The developed tool encompasses six main modules, including extraction of raw materials and production; construction, maintenance and rehabilitation; transportation of materials; work-zone traffic management; usage; and end-of-Life. Data regarding the Portuguese practise of Pavement construction and management have been collected on site with certified Portuguese construction companies and complemented using published literature and databases. The research described in this paper provides a widely applicable Pavement LCA model that will enable highway agencies, private companies and t...
Ting Wang - One of the best experts on this subject based on the ideXlab platform.
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Life Cycle energy consumption and ghg emission from Pavement rehabilitation with different rolling resistance
Journal of Cleaner Production, 2012Co-Authors: Ting Wang, Alissa Kendall, John T HarveyAbstract:Abstract This paper describes a Pavement Life Cycle assessment (LCA) model developed to evaluate energy use and greenhouse gas (GHG) emissions from Pavement rehabilitation strategies. The LCA model analyzes the energy and GHG emissions associated with material production, construction and Pavement use, which includes the effects of Pavement rolling resistance on vehicle operation. The model was used to evaluate a set of case studies of Pavement rehabilitation for both asphalt and concrete surfaces with different rolling resistances and traffic levels. The primary goal of the case studies is to evaluate the effect of rolling resistance on the Life Cycle performance of Pavements, not to compare asphalt and concrete Pavements. Energy and GHG emission savings from Pavement rehabilitation are compared with an alternative where no rehabilitation occurs, only routine maintenance of damaged Pavement. The results of the case studies show that for highway sections with high traffic volumes the energy and GHG savings accrued during the use phase due to reduced rolling resistance can be significantly larger than the energy use and GHG emissions from material production and construction, with the extent of the benefit dependent on constructed smoothness. These savings can be larger than those from other strategies to reduce highway transportation energy use and emissions, such as projected improvements in vehicle fuel economy. For low traffic volume highways, the smoothness obtained by the contractor and materials used have a more significant effect on the performance of the rehabilitation, and may result in a net increase in energy use and GHG emissions if low traffic volumes and poor construction quality occur together.
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ucprc Life Cycle assessment methodology and initial case studies for energy consumption and ghg emissions for Pavement preservation treatments with different rolling resistance
University of California Pavement Research Center Research Report, 2012Co-Authors: Ting Wang, John T Harvey, Alissa Kendall, Is Lee, Eulbum Lee, Changmo KimAbstract:This report describes a Pavement Life Cycle assessment (LCA) model developed to initially evaluate total energy use and greenhouse gas (GHG) emissions from Pavement maintenance and rehabilitation (MR at this time the model does not include the effects of Pavement deflection. Other types of treatments and the materials used for them, as well as other effects of the Pavement on the environment in the Pavement Use Phase will be considered in future studies. The model was used to evaluate four case studies of Caltrans Pavement preservation treatments for both asphalt and concrete surfaces with different roughness and texture and traffic levels. The case studies were performed to provide a preliminary indication of the net effect of changing the roughness and texture on the analysis period performance of Pavements, not to compare asphalt and concrete Pavements. At this time, asphalt and concrete Pavements cannot be directly compared because submodels are not yet included in the LCA model for factors in the Use Phase other than roughness and texture. For this reason, it was assumed that the Pavement preservation treatments would not change the Pavement structure type (asphalt or concrete). Energy and GHG-emissions savings from Pavement preservation treatments with CAPM treatments as an example (CPR B involving diamond grinding with 3 percent slab replacements for concrete and Pavement preservation overlays for asphalt, performed using nighttime closures) were then compared with an alternative strategy where no treatment occurs, except for routine maintenance of damaged Pavement. A preliminary indication of the sensitivity of the case study results to the level of smoothness achieved during Pavement preservation construction was evaluated. A preliminary indication of the sensitivity of the net effect on GHG emissions and energy use to the level of traffic in the Use Phase was also evaluated by inclusion of a high and a low traffic case study for both concrete and asphalt Pavements. The potential benefits of the treatments are also compared with energy and emissions savings from projected improvements in vehicle fleet fuel economy and reductions of vehicle miles traveled, which are strategies adopted by the California Air Resources Board for reducing GHG emissions. For highways with high traffic volumes, results of the case studies show that the energy and GHG savings accrued during the Use Phase (due to reduced roughness and macrotexture change) can be significantly larger than the energy use and GHG emissions from material production and construction. The extent of the benefit was dependent on constructed smoothness with a much smaller benefit from change of texture. These savings can be larger than those from other strategies meant to reduce highway transportation energy use and emissions for a given route, such as projected improvements in fleet average vehicle fuel economy within the period analyzed for the project location, depending on the amount of traffic using the Pavement. For low traffic volume highways, the smoothness obtained by the contractor and the materials used determine whether the net effect on GHG emissions and energy use is positive or negative, and may result in a net increase in energy use and GHG emissions if low traffic volumes and poor construction quality (rough Pavement produced by construction) occur together. These initial case studies only represent example sections, and application of the LCA model to the network remains to be done. The materials datasets for the case studies used data from several sources outside California that were adjusted to California electrical energy supplies. Sensitivity analysis with the different data sets did not change the conclusions. All materials mix designs (taken from meetings with industry) and construction were representative examples. The method used to combine Pavement characteristics (IRI and texture) and emissions models has not been validated, although the fuel economy models have been validated by Michigan State University. This report was reviewed by concrete and asphalt industry experts through their respective California industry organizations, and errors and omissions in the original draft have been addressed based on those comments, which are gratefully acknowledged.
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Pavement Life Cycle assessment workshop may 5 7 2010 in davis california usa
International Journal of Life Cycle Assessment, 2011Co-Authors: J Harvey, Alissa Kendall, Nicholas J Santero, Thomas J Van Dam, I S Lee, Ting WangAbstract:Purpose A workshop was convened on Life Cycle assessment (LCA) applied to Pavement. The workshop’s primary goals were to establish common practices for conducting LCAs for Pavements. In general, Pavement LCA has been implemented without clear guidelines for modeling assumptions and reporting. This shortcoming has led to challenges in interpreting and comparing Pavement LCA outcomes.
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Pavement Life Cycle assessment workshop discussion summary and guidelines
University of California Pavement Research Center Technical Memorandum, 2010Co-Authors: J Harvey, Alissa Kendall, Nicholas J Santero, I S Lee, T Van Dam, Ting WangAbstract:Although there have been several Life Cycle assessment (LCA) studies on the subject of Pavement, nearly all of them have focused on Pavement type selection (asphalt or concrete) for new Pavements for a narrow range of conditions, and the results have offered conflicting answers to questions about the resulting environmental impacts. This inconsistency is due to the lack of consistent LCA practice and to use of different data sources. Among the specific recurring problems found in LCA are unrepresentative functional units and analysis periods, a lack of transparency in impact allocation of the bitumen-refining process, and incomplete consideration of the full Life Cycle. To address these issues work has been undertaken to develop recommended common practices for conducting LCA for Pavements. The first-stage research product intended for Pavement LCA practitioners is the UCPRC Pavement LCA Guideline, which includes a highlevel LCA framework for Pavements, as well as some recommended data and models that have been used in California and elsewhere in the U.S. In May 2010, a workshop was held in Davis, California, to discuss the first draft of this guideline, and to answer some key questions regarding LCA practice and the application of the results. This technical memorandum contains a summary of the workshop discussions and the final draft Guideline based on the discussions.