Asphalt production consumes considerable amount of fuel and electric energy as significant amount of materials (bitumen and aggregates) are blended together for the construction of flexible pavements. Bitumen is used in asphalt as a binder but can also be used as an alternate energy source. Feedstock energy of bitumen becomes relevant in the life cycle cost (LCC) study, as cost of the binder would be reflected in its alternative value as fuel. In this study, a method was suggested to calculate energy content of the bitumen. Importance of choosing electricity not produced in local diesel generators was also demonstrated. Replacing fuel with inefficiently produced electricity for heating the materials in the asphalt plant would result in high environmental impacts. The calculation of feedstock energy and the understanding of efficient energy production and use could be utilized in the life cycle assessment (LCA) of the roads.
The construction, maintenance and disposal of asphalt pavements may lead to considerable environmental impacts, in terms of energy use and emissions during the life of the pavement. In order to enable quantification of the potential environmental impacts due to construction, maintenance and disposal of roads, an open life cycle assessment (LCA) framework for the asphalt pavements is presented in this paper. Emphasis was placed on the calculation and allocation of energy used for binder and additives at the project level. It was concluded from this study that when progressing from LCA to its corresponding life cycle cost, the feedstock energy of the binder becomes highly relevant as the cost of the binder will be reflected in its alternative value as fuel. Regarding additives like wax, a framework for energy allocation was suggested. The suggested project level LCA framework was demonstrated in a limited case study of a Swedish asphalt pavement. It was concluded that the asphalt production and transporting materials were the two most energy-consuming processes, emitting most greenhouse gases depending on the fuel type and electricity mix.
Life cycle assessment (LCA) methodology can be used to assess the environmental impacts of a road system over its entire life time. However, it is very important to align the potentials and limitations of such tools with their intended purpose. For the LCA to be useful for the decision support in a procurement situation, it should therefore be important to have a clear understanding of the technical features (attributes) that build up the life cycle phases. In this paper, different types of decisions situations are outlined based on at what level of complexity (network or specific project) and at what stage within the planning process (early planning or late planning/design) the decision is to be made, and relevant methodological choices for these decision situations are discussed. Further, the attributes that are important to consider in an asphalt road LCA that seeks to serve as a decision support in a procurement situation are suggested and technical features for these attributes are outlined with focus on Energy and GreenHouse Gas emissions. It can be concluded that in order to aid the implementation of green procurement, it would help if the attributes of the system are defined in a transparent manner and consistently calculated. It is, however, also important that the attributes should mirror the material properties used in a pavement design and therefore be closely linked to the performance of the road in its life time. It is also recommended to report the feedstock energy in the road LCAs.
Energy use and greenhouse gas (GHG) emissions associated with life cycle stages of roadinfrastructure are currently rarely assessed during road infrastructure planning. This studyexamines the road infrastructure planning process, with emphasis on its use of EnvironmentalAssessments (EA), and identifies when and how Life Cycle Assessment (LCA) canbe integrated in the early planning stages for supporting decisions such as choice of roadcorridor. Road infrastructure planning processes are compared for four European countries(Sweden, Norway, Denmark, and the Netherlands).The results show that only Norway has a formalised way of using LCA during choiceof road corridor. Only the Netherlands has a requirement for using LCA in the laterprocurement stage. It is concluded that during the early stages of planning, LCA could beintegrated as part of an EA, as a separate process or as part of a Cost-Benefit Analysis.
Road infrastructure has effects on the environment throughout all of its life cycle phases: construction,maintenance, operation and end-of-life. It has been observed, however, that these life cycle impacts are notusually considered during early stages of road infrastructure planning (i.e. decisions on road corridor).The recently developed LICCER tool enables assessment of road corridor alternatives during early stages of roadinfrastructure planning. It includes input data for roads, bridges and tunnels. It also considers future emissionsfrom traffic. The life cycle impact categories covered are energy use and contribution to climate change.The developed tool is being tested in a case study. Construction of a specific road in Sweden was used todemonstrate how the model is able to show differences between road corridor alternatives. Sensitivity analysiswas applied to show the robustness of its results.
Life Cycle Cost Analysis (LCCA) provides cost estimation over the life time of a project and thereby helps road administrations, designers, and contractors with choosing an economical design. Calculation of the costs can be based on a pavement design model, such as the Calibrated Mechanistic model (CM), in order to capture the mechanical behaviour of the asphalt pavement. This study aimed to develop an approach for performing comparative LCCA in order to find the most economical design alternative in terms of the total cost for the pavement design life. The integrated LCCA-CM approach was used to evaluate different design alternatives with different rehabilitation intervals for asphalt pavements.
A life cycle costing system should include the key variables that drive future costs in order to provide a framework for reducing the risk of under- or overestimating the future costs for maintenance and rehabilitation activities. In Sweden, price of oil products is mostly affected by the global economy rather than by the national economy. Whereas the price index of oil products has had a high fluctuation in different time periods, the cost fluctuation related to labour and equipment has been steady and followed the consumer price index (CPI). Contribution of the oil products was shown to be more than 50% of the total costs regarding construction and rehabilitation of asphalt pavements in Sweden. Consequently, it was observed that neither Swedish road construction price index (Vagindex) nor CPI has properly reflected the price trend regarding the asphalt pavement construction at the project level. Therefore, in this study, a framework is suggested in which energy- and time-related costs are treated with different inflation indices in order to perform a better financial risk assessment regarding future costs.
There are several incentives for using bottom ash from municipal solid waste incineration (MSWI bottom ash) as a construction material, such as for road construction. These incentives include decreased disposal of material on landfills and a reduced amount of raw material extracted for road building purposes. However, one of the main obstacles to utilising the material is uncertainties regarding its environmental properties. The overall objective of this thesis is to describe the potential environmental impacts of utilising MSWI bottom ash in constructions and to improve the tools for environmental assessments.
An environmental systems analysis (ESA) approach based on a life cycle perspective was outlined and used in a case study, with the aim of describing the differences in resource use and emissions that can be expected if crushed rock in the sub-base of a road in the Stockholm region in Sweden were to be substituted by MSWI bottom ash. The whole life cycle of the road was taken into account and the alternative disposal of the bottom ash was included. It was found that the studied alternatives would cause different types of potential environmental impact; whereas the conventional alternative with only crushed rock in the road’s sub-base would lead to larger use of energy and natural resources, the alternative with MSWI bottom ash in the sub-base would lead to larger contaminant leaching. It was concluded that a life cycle approach is needed in order to include both resource use and emissions in the comparison between the two alternative scenarios. The leaching of metals turned out to be the most important environmental aspect for the comparison and in particular the difference in copper (Cu) leaching was shown to be large.
However, a large amount of Cu may not pose an environmental threat if the Cu is strongly bound to dissolved organic carbon (DOC). In order to improve the basis for toxicity estimates and environmental risk assessments, and thereby provide better input values for ESAs, the speciation of Cu to DOC in MSWI bottom ash leachate was studied. It was found that Cu to a large extent was bound to DOC, which is consistent with previous research. The results also suggest that the hydrophilic fraction of the MSWI bottom ash DOC is important for Cu complexation and that the pH-dependence for Cu complexation to MSWI bottom ash DOC is smaller than for natural DOC. This implies that models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate.
In order to manage municipal solid waste incineration (MSWI) bottom ash safely, risk assessments, including the prediction of leaching under different field conditions, are necessary. In this study, the influence of salt or dissolved organic matter (DOM) in the influent on metal leaching from MSWI bottom ash was investigated in a column experiment. The presence of salt (0.1 M NaCI) resulted in a small increase of As leaching, whereas no impact on leachate concentration was found when lakewater DOM (35.1 mg/I dissolved organic carbon) was added. Most of the added DOM was retained within the material. Further, X-ray spectroscopy revealed that Cu(II) was the dominating form of Cu and that it probably Occurred as a CuO-type mineral. The CU2+ activity in the MSWI bottom ash leachate was most likely determined by the dissolution of CuO together with the formation of Cu-DOM complexes and possibly also by adsorption to (hydr)oxide minerals. The addition of lake DOM in the influent resulted in lower saturation indices for CuO in the leachates. which may be due to slow CuO dissolution kinetics in combination with strong Cu-DOM complexation.
Mängderna askor som används i konstruktioner utanför deponiområden är idag små. Några av orsakerna till detta har i tidigare projekt identifierats som svårtolkat regelverk, brist på kompetens och erfarenhet, för små mängder askor ger svag ekonomi, materialval kommer in sent i planering och projektering av ett projekt och metodik för miljöpåverkan av alternativa material saknas. Syftet med detta projekt var att kommunicera och överföra forskningsresultat om miljösystemanalys för askanvändning till praktisk tillämpning, undersöka hur ett livscykelperspektiv påverkar beslutsunderlag för nyttiggörande av avfallsaskor och föreslå hur livscykelperspektivet kan tillämpas praktiskt i beslutsprocessen. Målgruppen för rapporten är aktörer som vill komma fram till ett välgrundat beslut om användning av askor i anläggningsbyggande. Huvudfokus i rapporten har varit miljömyndigheters perspektiv på frågeställningen.Enligt praxis ärvd från den tidigare miljöskyddslagen tillämpas prövningen av projekt enbart på den lokala påverkan som verksamheten i fråga kan medföra och på avfallsbegreppet i den absoluta majoriteten av alla ärenden. Viktiga miljöfrågor som t ex växthuseffekten, försurning, övergödning, resurshushållning och eventuella miljökonsekvenser i andra delar av samhället beaktas inte. Det finns dock stöd i miljöbalken för att inkludera dessa större frågeställningar. Ett verktyg för att visa konsekvenserna är miljösystemanalys. En miljösystemanalys kan vidga perspektivet vid bedömningen av hänsynsreglerna och därigenom ge bättre beslut om användning av askor. Ett sätt att säkerställa objektiviteten och tillförlitligheten hos denna typ av studier är att använda känslighetsanalyser och att redovisa analyserna på ett transparent sätt. Det finns potential att implementera livscykelperspektiv i beslut om askanvändning, framförallt i miljömålsarbete, i regional och kommunal planering, eller direkt i anmälnings- och tillståndsärenden. I utformningen av regionala miljömål kan livscykelperspektivet användas för att ta fram underlag för beslut om åtgärder samt vid uppföljning av miljömål.Ett ytterligare område som rör askanvändning och där det finns god potential att införa livscykelperspektivet är i materialförsörjningsplaner. Detta kan ske genom att de scenarier som beskrivs i materialförsörjningsplanerna analyseras med avseende på miljöpåverkan ur ett livscykelperspektiv, där olika typer av förväntad miljöpåverkan för de olika scenarierna kvantifieras. Det krävs dock att materialförsörjningsplanen används som ett underlag i tillstånds- eller anmälningsärenden för konstruktioner med askor, för att detta ska få någon praktisk effekt. En förutsättning för detta är en god kommunikation mellan kommunernas plansida och miljösida.Huvudslutsatsen av detta projekt är att det krävs ett livscykelperspektiv för att uppfylla kraven om avvägningar av olika miljöaspekter enligt både miljöbalken och de svenska miljökvalitetsmålen och på detta sätt ge bättre underlag för beslut om askanvändning.
Bottom ash, originating from municipal solid waste incineration (MSWI), is a potential road construction material. The aim of this study was to describe what differences in resource use and emissions that can be expected if crushed rock in the sub-base of a road in the Stockholm region in Sweden were to be substituted by MSWI bottom ash, taking into account the whole life cycle of the road and including alternative disposal of the bottom ash. An environmental systems analysis approach based on a life cycle perspective was outlined and used in a case study. It was found that the studied alternatives would cause different types of potential environmental impact; whereas, crushed rock in the road's sub-base would lead to larger use of resources, the alternative with MSWI bottom ash in the sub-base leads to a larger contaminant leaching. The results are sensitive to the transport distance for the road material and to conditions affecting the leaching from the road. The differences between energy uses in the two alternatives derive mainly from production of crushed rock and from landfilling of MSWI bottom ash, whereas, the metal emissions occur in the use stage of the road's life cycle.
Information on Cu speciation in municipal solid waste incineration (MSWI) bottom ash leachate is needed for Cu leaching predictions and toxicity estimates. The complexation of Cu with dissolved organic matter (DOM) in leachates from a stored MSWI bottom ash was studied potentiometrically using a Cu-ion selective electrode. More than 95% of the copper was bound to DOM in the hydrophilic fraction of the leachate, indicating that the hydrophilic acids contribute to Cu complex formation. The hydrophilic acids constituted 58% of the dissolved organic carbon in the ash leachate. Comparisons between experimental results and speciation calculations with the NICA-Donnan model and the Stockholm humic model indicated differences between the ash DOM and the natural DOM for which the models have been calibrated. The ratio of carboxylic binding sites to phenolic binding sites was 2 times larger in ash DOM, and the Cu-binding affinity of the former was stronger than accounted for by the generic Cu-binding parameters. The Cu-binding affinity of the phenolic sites, on the other hand, was weaker. When these parameters were adjusted, a good description of the experimental data was obtained.
In Sweden, utilisation of incinerator residues outside disposal areas is restricted by environmental concerns, as such residues commonly contain greater amounts of potentially toxic trace elements than the natural materials they replace. On the other hand, utilisation can also provide environmental benefits by decreasing the need for landfill and reducing raw material extraction. This thesis provides increased knowledge and proposes better approaches for environmental assessment of incinerator residue utilisation, particularly bottom ash from municipal solid waste incineration (MSWI).A life cycle assessment (LCA) based approach was outlined for environmental assessment of incinerator residue utilisation, in which leaching of trace elements as well as other emissions to air and water and the use of resources were regarded as constituting the potential environmental impact from the system studied. Case studies were performed for i) road construction with or without MSWI bottom ash, ii) three management scenarios for MSWI bottom ash and iii) three management scenarios for wood ash. Different types of potential environmental impact predominated in the activities of the system and the scenarios differed in use of resources and energy. Utilising MSWI bottom ash in road construction and recycling of wood ash on forest land saved more natural resources and energy than when these materials were managed according to the other scenarios investigated, including dumping in landfill. There is a potential for trace element leaching regardless of how the ash is managed.Trace element leaching, particularly of copper (Cu), was identified as being relatively important for environmental assessment of MSWI bottom ash utilisation. CuO is suggested as the most important type of Cu-containing mineral in weathered MSWI bottom ash, whereas in the leachate Cu is mainly present in complexes with dissolved organic matter (DOM). The hydrophilic components of the DOM were more important for Cu binding than previously understood. Differences were also observed between MSWI bottom ash DOM and the natural DOM for which the geochemical speciation models SHM and NICA-Donnan are calibrated. Revised parameter values for speciation modelling are therefore suggested. Additions of salt or natural DOM in the influent did not change the leachate concentration of Cu. Thus, although Cl and natural DOM might be present in the influent in the field due to road salting or infiltration of soil water, this is of minor importance for the potential environmental impact from MSWI bottom ash.This thesis allows estimates of long-term leaching and toxicity to be improved and demonstrates the need for broadening the system boundaries in order to highlight the trade-offs between different types of impact. For decisions on whether incinerator residues should be utilised or landfilled, the use of a life cycle perspective in combination with more detailed assessments is recommended.
In order to assess the environmental impact of the Swedish building and property (real estate) management sector, a new top-down life cycle assessment (LCA) method was used which was based on inputoutput analysis using national statistical data. Six indicators were developed as suitable for environmental monitoring of the sector: energy use; emissions of greenhouse gases; emissions of nitrogen oxides; emissions of particulates; use of hazardous chemical products; and generation of waste. These indicators were then used to describe the environmental performance of the sector over a 15-year period in order to monitor change and improvement. The use of energy and emissions to air can be effectively followed in time-series. These indicators could be used to create incentives to evaluate regularly improvement work and to inform policy and practice. For greenhouse gas emissions, a trend was identified for space heating to become less important than construction and management towards the end of the period studied, most likely due to a transition from fossil fuels to renewable fuels for heat production. Key implications will be on the selection of building materials, the construction process and the extension of building longevity.
Incineration ashes may be treated either as a waste to be dumped in landfill, or as a resource that is suit able for re-use. In order to choose the best management scenario, knowledge is needed on the potential environmental impact that may be expected, including not only local, but also regional and global impact. In this study. A life cycle assessment (LCA) based approach Was Outlined for environmental assessment of incinerator residue utilisation, in which leaching of trace elements as well as other emissions to air and water and the use of resources were regarded as constituting the potential environmental impact from the system studied. Case Studies were performed for two selected ash types, bottom ash from municipal solid waste incineration (MSWI) and wood fly ash. The MSWI bottom ash was assumed to be suitable for road construction or as drainage material in landfill, whereas the wood fly ash Was assumed to be suitable for road construction or as a nutrient resource to be recycled oil forest land after biofuel harvesting. Different types of potential environmental impact predominated in the activities of the system and the use of natural resources and the trace element leaching were identified as being relatively important for the scenarios compared. The scenarios differed in use of resources and energy, whereas there is a potential for trace element leaching regardless of how the material is managed. Utilising MSWI bottom ash in road construction and recycling of wood ash on forest land saved more natural resources and energy than when these materials were managed according to the other scenarios investigated, including dumping in landfill.
One of the key features of environmental policy integration in Sweden is sectorresponsibility. The National Board of Housing, Building and Planning is responsible for the building and real estate management sector and should, as a part of this responsibility, assess the environmental impacts of this sector. The aim of this study is to suggest and demonstrate a method for such an assessment. The suggested method is a life cycle assessment, based on an input-output analysis. The method can be used for regular monitoring and for prioritization between different improving measures. For the assessment to sufficiently cover the Swedish Environmental Quality Objectives, complementary information is needed, in particular with respect to the indoor environment. According to the results, the real estate management sector contributes between 10% and 40% of Swedish energy use; use of hazardous chemical products; generation of solid waste; emissions of gases contributing to climate change; and human toxicological impacts, including nitrogen oxides (NOx) and particulates. Transport and production of nonrenewable building materials contribute significantly to several of the emissions. Heating of buildings contributes more to energy use than to climate change, due to the use of renewable energy sources. To reduce climate change, measures should therefore prioritize not only heating of buildings but also the important upstream processes.