No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Hybrid Life-Cycle Inventory for Road Construction and Use
Abstract
Life-cycle assessment (LCA) is a technique that is used worldwide by clients and their design team to assess the impact of
their projects on the environment. The main advantage of LCA is in supporting decision making with quantitative data. LCA inventories
can be either fully developed or streamlined. Fully developed LCAs are time-consuming and costly to prepare. Streamlined LCAs can be
used as an effective decision-making tool when considering environmental performance during the design process, but with a loss of
inventory completeness. Acknowledging the advantages and disadvantages of both types of LCA, this paper proposes a hybrid LCA
method that uses input-output data to fill in those gaps routinely left in conventional LCA inventories.<br /
... [10], [9], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [63], [64], [65], [66], [67], [68], [69] Input-output 8 (12.5%) [70], [71], [33], [72], [73], [18], [34], [74] Hybrid 11 (17.2%) [75], [76], [77], [78], [79], [80], [81], [82], [83], [84], [85] Others (ANN, regression, etc.) 8 (12.5%) [86], [87], [88], [89], [90], [91], [1], [92] Total 64 (100%) [37], [77], [78], [79], [80], [47], [56], [57], [73], [10], [35], [76], [38], [82], [83], [52], [ [39], [45], [33], [81], [49], [84], [72], [86], [ [88], [91], [59], [64], [66], [1] -√ ---12 (18.8%) [50], [51], [53], [54], [58], [87], [89], [60], [63], [65], [68], [ ...
... [10], [9], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [63], [64], [65], [66], [67], [68], [69] Input-output 8 (12.5%) [70], [71], [33], [72], [73], [18], [34], [74] Hybrid 11 (17.2%) [75], [76], [77], [78], [79], [80], [81], [82], [83], [84], [85] Others (ANN, regression, etc.) 8 (12.5%) [86], [87], [88], [89], [90], [91], [1], [92] Total 64 (100%) [37], [77], [78], [79], [80], [47], [56], [57], [73], [10], [35], [76], [38], [82], [83], [52], [ [39], [45], [33], [81], [49], [84], [72], [86], [ [88], [91], [59], [64], [66], [1] -√ ---12 (18.8%) [50], [51], [53], [54], [58], [87], [89], [60], [63], [65], [68], [ ...
... [42], [44], [45], [33], [55], [72], [88], [85], [91], [64], [34], [66], [67], [1], [74] Rigid pavement (concrete) 8 (12.5%) [43], [46], [37], [81], [90], [59], [61], [18] Flexible and rigid pavement (both asphalt and concrete) 24 (37.5%) [10], [9], [70], [35], [36], [76], [39], [40], [41], [78], [79], [80], [82], [83], [47], [48], [49], [50], [84], [52], [56], [57], [73], [62] Others part of road pavement (earthwork, polyurethane, etc.) 15 (23.4%) [38], [77], [51], [53], [54], [86], [58], [87], [89], [60], [63], [65], [68], [69], [92] Total 64 (100%) ...
LCA has been utilized over the past two decades to estimate the environmental impacts of pavement in infrastructures. The purpose of this study is to systematically map research on the use of LCA to calculate energy and emissions in road infrastructure projects. The research method is carried out by a literature review, in terms of systematic mapping study of a number of previous scientific publications, in the form of documents that have been published in international and national journals and proceedings, etc., in the last thirty years. The results show that: The topic of LCA is still an interesting area of research, and the trend from year to year shows an increase in the publication of articles in reputable journals. As much as 57.8% research, using the process based calculation method. Only 15.6% of research calculated energy and emissions in the four completed stages of the project life cycle. As much as 37.5% research compared the flexible and rigid pavement as research objects. There is a chance to research the development of the energy optimization model for road infrastructure projects using cradle to cradle system boundary, from initiation to the end of life as a whole project life cycle.
... The emission sources of the use phase usually include the vehicle life cycle, on-road vehicles, and the impact of pavement performance changes such as RR, deflection, albedo, and carbonation. The vehicle life cycle is only considered in Treloar et al. (2004), which is one of the earliest studies that have considered the use phase. On-road vehicle emissions is more frequently considered as road traffic are considered to be part of road operations (Treloar et al., 2004). ...
... The vehicle life cycle is only considered in Treloar et al. (2004), which is one of the earliest studies that have considered the use phase. On-road vehicle emissions is more frequently considered as road traffic are considered to be part of road operations (Treloar et al., 2004). However, this practice is facing challenges recently. ...
... The PXC method proposed by Treloar et al. (2004) is adopted in evaluating emissions from onsite equipment operation and embedded emissions, which includes below four steps: 1) Building an EIO LCA model for roads using Eqs. (1) and (2) (Treloar et al., 2004). ...
Road infrastructure is an important source of carbon emissions. To estimate the carbon emissions of roads, life cycle assessment (LCA) methods are widely used. Due to budget constraints, road maintenance and rehabilitation (M&R) is preferred by road agencies over new construction. However, existing LCA studies on roads have limited considerations on the emissions from the use and M&R phases. This study aims to propose and illustrate a structured hybrid LCA approach that can be adopted by road agencies to evaluate carbon emissions of the use and M&R phases of roads. A path exchange LCA method and a tiered hybrid LCA method are integrated in the proposed approach. To illustrate the proposed approach, a case study of a road network in Western Australia is conducted, which includes 17,764 road segments. The results show that from 2017 to 2026, the GWP of use and M&R phases is increased from 467.8 t CO2-e/km to 589.5 t CO2-e/km·with an increasing trend. The use phase has much higher global warming potential than the M&R phase during the service life of roads. The results are the most sensitive to annual average daily traffic (AADT). In addition, heavy traffic roads in the metropolitan area and freeways with AADT higher than 20,000 are identified to be the most carbon intensive. The proposed approach is believed to have better accuracy when compared to a process-based approach and a tiered approach, which provide the results of 128.6-164.4 t CO2-e/km and 468.0-608.9 t CO2-e/km, respectively. The results can provide implications for road authorities to evaluate their priorities when allocating limited M&R funds to achieve sustainable objectives.
... Stripple chose to analyze road sections with a functional unit of 1 km road length, which forms the basis of other prominent LCA road studies. Treloar et al. (2004) is also notable for including traffic information in the analysis of a rural Australian road system. This study defined multiple fixed road typologies and compared them to one another by utilizing a hybrid LCA over a 40 year period and normalizing to per meter road length. ...
... Few full road infrastructure LCA studies, such as Stripple (2001) and Treloar et al (2004), have included traffic as part of the overall analysis. An analysis without traffic risks being insufficient and can lead to flawed decision-making in road construction planning. ...
... When using such a project-specific functional unit, however, results cannot be easily compared to those of other projects, or other unrelated routes. Previous LCA studies on road infrastructure have chosen functional units that compare road alternatives and sections in terms of meter length of built road (Barandica, Fernandez-Sanchez, Berzosa, Delgado and Acosta, 2013), (Huang, Hakim, & Zammataro, 2013), fixed road dimensions and fixed traffic (Treloar, Love, and Crawford, 2004), or fixed time horizons (ECRPD, 2010). Given the complexity of road projects and the difficulties with compiling data on multiple alternatives in pre-construction and planning phases, it is critical that the functional unit is chosen in line with the objectives of the study and not with generic information. ...
... The environmental impacts of a product can be effectively evaluated by Life Cycle Analysis, or LCA. An LCA is divided into five main stages of evaluations: raw material extraction, manufacturing, transportation, use, and end of life (Horvath, 2003;Hoxha et al., 2021;Stripple, 2001;Treloar, Love, & Crawford, 2004). Each of these stages is broken down into unit processes with various inputs and outputs to ascertain their environmental impacts. ...
... Huang, Bird, & Heidrich, 2009;Klöpffer, 1997;Vigon et al., 1993). With some degree of process and terminology standardization, several studies featuring LCA of roads appeared in the literature in the early 2000s (Horvath, 2003;Hoxha et al., 2021;Stripple, 2001;Treloar et al., 2004). ...
... This leads to the development of a model design problem with conflicting objectives-increasing resolution while decreasing data requirements. Looking into a wide range of hybrid LCA studies (Treloar et al. 2001;Treloar et al. 2004;Stokes and Horvath 2006;Wiedmann et al. 2011;Pairotti et al. 2015;Hou et al. 2014;Bilec et al. 2006;Rowley et al. 2009), it is seen that the decision of distributing life cycle activities between the scales of hybrid LCA model is subjective. While most studies decide the boundary based on experience, data availability, cost, and time requirements, Treloar et al. (2001) and Treloar et al. (2004) used structural path analysis (SPA) to extract the hotspots of environmental impacts in the life cycle of a product in terms of contribution to the total emission. ...
... Looking into a wide range of hybrid LCA studies (Treloar et al. 2001;Treloar et al. 2004;Stokes and Horvath 2006;Wiedmann et al. 2011;Pairotti et al. 2015;Hou et al. 2014;Bilec et al. 2006;Rowley et al. 2009), it is seen that the decision of distributing life cycle activities between the scales of hybrid LCA model is subjective. While most studies decide the boundary based on experience, data availability, cost, and time requirements, Treloar et al. (2001) and Treloar et al. (2004) used structural path analysis (SPA) to extract the hotspots of environmental impacts in the life cycle of a product in terms of contribution to the total emission. However, it is difficult to judge based on the emission quantities if a certain activity is significant enough to be modeled at a particular scale. ...
PurposeDespite the wide use of LCA for environmental profiling, the approach for determining the system boundary within LCA models continues to be subjective and lacking in mathematical rigor. As a result, life cycle models are often developed in an ad hoc manner, and are difficult to compare. Significant environmental impacts may be inadvertently left out. Overcoming this shortcoming can help elicit greater confidence in life cycle models and their use for decision making.Methods
This paper describes a framework for hybrid life cycle model generation by selecting activities based on their importance, parametric uncertainty, and contribution to network complexity. The importance of activities is determined by structural path analysis—which then guides the construction of life cycle models based on uncertainty and complexity indicators. Information about uncertainty is from the available life cycle inventory; complexity is quantified by cost or granularity. The life cycle model is developed in a hierarchical manner by adding the most important activities until error requirements are satisfied or network complexity exceeds user-specified constraints.Results and DiscussionThe framework is applied to an illustrative example for building a hybrid LCA model. Since this is a constructed example, the results can be compared with the actual impact, to validate the approach. This application demonstrates how the algorithm sequentially develops a life cycle model of acceptable uncertainty and network complexity. Challenges in applying this framework to practical problems are discussed.Conclusion
The presented algorithm designs system boundaries between scales of hybrid LCA models, includes or omits activities from the system based on path analysis of environmental impact contribution at upstream network nodes, and provides model quality indicators that permit comparison between different LCA models.
... In forestry, environmental impact studies usually exclude forest transport infrastructure impact, which is correlated, according to Treloar et al. (2004), to road construction, maintenance and use, due to its high complexity, where a complete LCA of forest roads is difficult and time consuming, and it depends on the system boundaries and on the number of inputs in the process analysis. Treloar et. ...
... es usually exclude forest transport infrastructure impact, which is correlated, according to Treloar et al. (2004), to road construction, maintenance and use, due to its high complexity, where a complete LCA of forest roads is difficult and time consuming, and it depends on the system boundaries and on the number of inputs in the process analysis. Treloar et. al (2004) and Sharrard (2007) state that a hybrid based process and inputoutput based LCA approach is recommendable for estimating project specific environmental impacts of forest roads. ...
Today, LCA is one of the leading and most used tools for environmental management, but the application of LCA in forestry is still in an initial phase. Due to a high amount of different wood products which can be produced in forestry sector, production of raw material itself is not included enough in the whole LCA process. Raw wood products and biomass used to be widely declared as »carbon neutral« and renewable, but production steps have a significant influence on the environmental impact depending on machinery used, opening forest with new roads, management type (clear-cut, even-aged management or selective cut), etc. This paper gives a review of LCA studies in forestry based on three segments:
harvesting operations
biomass for energy
road construction and maintenance.
... These factors reflected the complex interaction between the pavement and the environment. Some scholars have also investigated the impact of vehicle-related factors on pavement emissions during the use phase, including vehicle age, engine type, fuel type, and more (Treloar et al., 2004). However, this review only considered emissions that directly result from road infrastructure or were caused by changes in road performance, without taking into account vehicle technology. ...
... Furthermore, prior empirical studies have primarily focused on the embodied energy, energy consumption, and environmental impacts of buildings, with limited attention given to energy access during the delivery of construction projects (Hegner 2007;Holtzhausen 2007;Langston 2008a, 2008b;Marszal et al. 2010;Dixit et al. 2010aDixit et al. , 2013. Only one study by Treloar et al. (2004) has examined energy access related to the extraction, production, and transportation of construction materials but did not address on-site construction processes. As a result, there is a gap in the literature regarding empirical studies on energy access during the delivery of construction projects, which this study aims to address. ...
... Workability is measured by the Flow The environmental assessment of the production of the above mixtures, is conducted according to the Life Cycle Assessment (LCA) methodology, as it is described in International Standards ISO 14040 [12] and 14044 [13]. From a contemporary materials' point of view [14][15][16][17], to the building [18,19] and infrastructure [20,21] scale, or the traditional materials point of view [22], LCA is widely used for the quantification of the environmental profile of both modern and historic projects. ...
The sustainable character of traditional building materials (lime, pozzolan) is usually considered self-evident due to their local character and proved durability. However, since there is a growing interest for validation of sustainability claims (through market tools such as EPDs), the comprehensive quantification of the sustainable character of a product is a priority for the construction sector, especially for products that combine traditional materials with alternative additions (such as industrial by-products). In this study, lime-based binding systems that incorporate industrial by-products of perlite production, are being assessed in terms of their sustainability potential. More specifically, the environmental aspect is considered and calculated by following the methodology of Life Cycle Assessment. To depict as accurately as possible the local conditions of production and application, an effort was made for data to be obtained mainly from Greek construction industry and from either experimental or on-site applications from the Laboratory of Building Materials of AUTH. Results are really promising regarding the environmental profile of combined systems, rendering them a viable and efficient solution for sustainable construction design.
... According to a study by the International Road Federation, the energy consumption of 1 km of two-lane asphalt pavement construction is about 7 × 10 6 MJ, which is equivalent to the calorific value of 240 tons of standard coal burning. Faced with the problem of resources and environment caused by the construction of asphalt pavement, China promotes asphalt pavement regeneration technology in the field of pavement construction, which can solve the problem of resource waste and the environmental impact of the road construction process to a greater extent [6,7]. ...
A quantitative evaluation was conducted on the energy consumption and carbon emissions during the asphalt pavement regeneration process, and the energy consumption and emission ratios during the construction and raw material production stages of the cold and hot regeneration process were obtained. This study applies the theory of life cycle assessment to propose an evaluation framework and calculation method suitable for quantitatively evaluating the environmental impact of the asphalt pavement regeneration process. Firstly, based on the life cycle evaluation theory, the evaluation framework and calculation method applicable to the quantitative study of the environmental impact of asphalt pavement regeneration processes are discussed, and the calculation formulae for the comprehensive energy consumption and comprehensive carbon emission of asphalt pavement regeneration are derived. It is found that the energy consumption and emission in the hot regeneration process account for 50~70% of the total process in the construction stage, and 50~65% of the total process in the cold regeneration process in the raw material production stage. Compared with the milling and resurfacing process, the energy consumption and carbon emission of the asphalt pavement regeneration process are reduced by about 16~66%, and the carbon emission is reduced by about 14~53%, so the energy saving and emission reduction benefits are more significant. The amount of RAP mixing, transportation distance of raw materials and pavement regeneration depth have a great influence on the energy consumption and emission of pavement regeneration. It can provide scientific guidance for the quantitative evaluation of the environmental impact of asphalt pavement regeneration, with a view to providing energy-saving and emission reduction level data support for technology improvement and engineering decisions.
... Häkkinen et al. [26] state that a top-down approach can be largely generic and involve more uncertainty, if the desired product is not directly represented by the industry data. However, in literature this method can be associated with time and cost savings [68], compared to a process-based approach [59]. ...
As it stands, the construction sector accounts for a significant proportion of global emissions. The majority of these emissions can be associated with material production. As a result, the importance of quantifying these environmental impacts is continually increasing. However, there is a current lack of guidance and methodologies regarding how to benchmark the impacts of construction products, and thus achieve more transparent environmental reporting and decision-making. Therefore, the aim of this study was to review engineering life-cycle assessment (LCA) literature and applicable standards to identify the key methodological variables required and the key steps for a sector-wide methodology. This was carried out via a bibliographic search for indexed, peer-reviewed journal publications and conference proceedings, project reports, and standards for constructed assets. From the search conducted, 23 documents and 4 standards were selected for review as relevant for this study. As a result, five key constituent methodological variables (study scope; model typology; benchmark approach; database selection; benchmark type) and three key steps (data collection; LCA; benchmark generation, with the option for Data Envelopment Analysis) were identified. Furthermore, considering the novel ISO 21678:2020, specific benchmark pathways were defined for the four types of benchmark values which can be obtained: limit, reference, short- and long-term. The definition of this set of steps, key methodological variables and the authors' recommendations for the construction sector constitute the first LCA benchmarking methodology on this field.
... These factors reflect the interaction between the road and the environment. Besides the factors directly related to roads, Treloar et al. (2004) have considered emissions from on-road vehicle operations and even the life cycle of vehicles. However, the emission from normal traffic is attributed to the vehicle life cycle or road transport life cycle, and it is not directly related to the life cycle of the road infrastructure (Fernandez-Sanchez et al., 2015;Loijos et al., 2013). ...
Carbon dioxide (CO2) emissions from the road sector have attracted increasing attention in current years. This paper attempted to provide a systematic review of the existing research efforts on road life-cycle CO2 emissions by analyzing the system’s boundary division, identifying the CO2 emission contributions of each life-cycle phase, listing major emission contributors, exploring related emission reduction technologies, and giving directions for future development. The research showed that the road life cycle is usually divided into five phases: material production, construction, use, maintenance and end-of-life (EOL) phases. The use phase and the initial construction stage (including material production and construction phases) contributed the most CO2 emissions during the road life cycle. In detail, the production of cement, asphalt and steel were the three main emission contributors in the material production phase. The pavement roughness, albedo, and concrete carbonation were the main factors affecting emissions in the use phase. In addition, emission reduction technologies such as using recycled materials and recycling techniques, lowering mixing temperature, and equipment energy substitution were commonly used to reduce emissions from material production and construction phases. The application of emerging technologies such as carbon capture and storage, carbon sink, and the use of hydrogen, solar and photovoltaic in the road sector may have emission reduction potentials and should be highlighted more in future studies.
... Pratt [21] stressed the importance of the domestic tourist market for the feasibility of rural wine tourism. Despite the heterogeneity of the rural wine tourists' sociodemographic profile, it seems consensual that most of these visitors are domestic [32] and come from relatively close places, just a few hours of travel from the place of residence [31]. There are even studies, for example concerning Northern Greece [33] and Aragon, Spain [34], in which none of the respondents had participated in international wine tourism experiences before. ...
Wine tourism is increasingly identified as an interesting tool for diversifying tourism destinations and attracting tourists to rural areas that otherwise lack tourism appeal. It is also recognized as a catalyst of sustainable rural development, stimulating local economy through both tourism and wine sales, by preserving tradition and local identity, and by enhancing the quality of life in some, particularly, more peripheral rural areas. However, not all rural wine tourism businesses and destinations are well-prepared to internationalize nor do they know what it takes to successfully attract and satisfy international travelers. A sound assessment of opportunities and challenges posed by internationalization and the decision to focus rather on the domestic market or develop the market, or even to diversify into new markets with new products, requires market understanding. It is in this context that the present study analyses data from both domestic and international travelers to three wine routes in rural territories in Central Portugal. Results reveal advantages and disadvantages associated with a focus on the domestic versus international market and the challenge of serving both in an attempt of internationalization, particularly in a rural wine destination context. Both theoretical and management implications are discussed.KeywordsRural wine tourismInternationalizationQuantitative study
... The results indicated material usage and maintenance stages are responsible for the highest energy consumption [50]. Another study used an energy-based hybrid life cycle assessment (LCA) model to assess the environmental impacts of road construction and usage [51]. The results indicated that the construction process is initially the most important phase and needs to be thoroughly considered to benchmark the life cycle benefits. ...
Due to its dynamic nature in construction, benchmarking environmental emissions of road construction projects can be a daunting task. Often stakeholders will have to prioritize the economic and environmental indicators based on the project objectives. The study presents a methodological framework to compare economic and environmental impacts to benchmark sustainable transport construction projects. Through findings, the study aims to inform focus areas and key stages of infrastructure projects to benchmark sustainable performance. Process-based emission and cost estimation models are presented with an AHP based weighting factor that enables prioritization of emissions and costs based on project scopes and objectives. Using a case study, results are represented to validate the framework and methodology. Concrete and steel are identified as the main materials that contribute to total carbon emissions, while soil and gravel are responsible for the highest costs. Electricity consumption is discovered as the major fuel type contributing to carbon emissions. Concrete and dump trucks are discovered as the top two sources of emissions and costs, respectively. Scenario analyses revealed that the choice of equipment significantly affects the project’s emissions and costs. The application of sustainable materials can significantly reduce emissions and cost. The use of the case study approach results in a lack of generalizability. However, the same methodology and process can be adopted for the sustainable benchmarking of different projects. Researchers are encouraged to investigate processes to automate sustainable benchmarking of transport infrastructure construction projects. The study is one of the first attempts to compare cost and environmental impacts using a systematic methodology of transportation infrastructure construction projects.
... Presently, there are plenty of research works assessing the energy consumption and environmental impacts of buildings, but few encompass the energy analysis in the construction process. However, this was limited to various stages of material extraction, production, and transportation and did not include on-site construction processes [7][8][9]. Calculation of the Life-Cycle Cost (LCC) considers the cost of energy utilized in the construction process. The energy consumption during construction is not well understood because of its fragmented nature and involvement of many parties during the construction phase [10]. ...
Effective energy utilization is a key parameter to meet the increasing global energy demand, and this paper proposes to install a solar PV array during the construction of a high-rise building. Electrical energy auditing is an essential tool for the planning and installation of solar PV systems. The outcome of energy auditing and the space availability are subsequently utilized for planning the sequential installation of solar PV systems in the four segments of the construction process. Several challenges in harnessing and utilizing solar energy during the construction, along with the strategic utilization of solar PV energy are presented for the benefit of building owners after the completion of the construction process. A case study (seven 200 m high rise buildings and associated facilities) is considered to validate the proposed energy-efficient construction process, and the same is compared with the conventional construction process. From the comparison, a significant reduction in the power drawn from the grid during the construction process is noticed. It has been found from the simulation results that an estimated annual energy of 7377 MWh is generated from the 3.63 MW roof-top solar PV systems. Further, a techno-economic assessment of the proposed solar PV system is drawn to bring out the financial benefits to the contractor, and the owners of the newly constructed high-rise residential buildings. Embracing sustainability in buildings with energy-efficient construction practices in large construction projects can substantially minimize the impact of environmental pollution.
... Each method has significant, unique benefits and drawbacks. According to Treloar et al. [8], the major drawback of most available methods is they encourage environmental responsibility in the construction industry instead of promoting environmental sustainability. More recently, several methods, such as those proposed by Stripple and Erlandsson [9], Santero et al. [10], and Bin Yu et al. [11], were developed to use LCA in environmental assessment. ...
Airports are a part of the world transportation network. Huge investments are made annually for airport pavement construction, maintenances and rehabilitations. The idea of integrating life-cycle cost analysis (LCCA) and life cycle assessment (LCA) is the latest approach to develop a method for assessing pavement sustainability. In this regard, research on economic evaluation analysis methods has resulted in the development and improvement of pavement management systems (PMS). This paper compares two main economic evaluations which mainly could use in LCCA namely net future value (NFV) and net present Value (NPV). To indicate the effect of economic evaluation a case study is examined. In this research LCCA comprises three main components which are direct costs, indirect costs, and salvage value. Airport Revenue Reduction Cost (ARRC) and Airline Delay Cost (ADC) considered as two specific indirect/user costs. The results show the impact of different economic analysis method on project decision-making where the use of crack sealing overlay (CSOL) is 35.8% and 28.3% more cost-effective than Portland cement concrete (PCC) and hot-mix asphalt (HMA), respectively.
... Each method has significant, unique benefits and drawbacks. According to Treloar et al. [8], the major drawback of most available methods is they encourage environmental responsibility in the construction industry instead of promoting environmental sustainability. More recently, several methods, such as those proposed by Stripple and Erlandsson [9], Santero et al. [10], and Bin Yu et al. [11], were developed to use LCA in environmental assessment. ...
Airports are a part of the world transportation network. Huge investments are made annually for airport pavement construction, maintenance and rehabilitation. The idea of integrating life-cycle cost analysis (LCCA) and life cycle assessment (LCA) is the latest approach to develop a method for assessing pavement sustainability. In this regard, research on economic evaluation analysis methods has resulted in the development and improvement of pavement management systems (PMS). This paper compares two main economic evaluations which mainly could use in LCCA namely net future value (NFV) and net present Value (NPV). To indicate the effect of economic evaluation a case study is examined. In this research LCCA comprises three main components which are direct costs, indirect costs, and salvage value. Airport Revenue Reduction Cost (ARRC) and Airline Delay Cost (ADC) considered as two specific indirect/user costs. The results show the impact of different economic analysis method on project decision-making where the use of crack sealing overlay (CSOL) is 35.8% and 28.3% more cost-effective than Portland cement concrete (PCC) and hot-mix asphalt (HMA), respectively.
... First, some studies analyzed the consumed resources and energy for the construction works already performed to present their impact on environmental loads. LCA studies have been performed for roads (Kwon, 2008;Thiel et al., 2014;Treloar et al., 2004;Moon et al., 2014), bridges (Hammervold et al., 2013;Lee, 2008), dams (Liu et al., 2013), and environmental facilities (Parrish and Chester, 2014), etc., and the basic unit quantity characteristics of their environmental loads have been established. In addition, research was conducted to provide baseline data for eco-friendly construction methods or material selection through environmental load analysis on specific construction methods or materials (Lounis and Daigle, 2007;Min, 2013). ...
To reduce the environmental loads of construction projects, a methodology needs to be established that reasonably assesses the environmental impact. Currently, life cycle assessment (LCA) is used as a methodology for evaluation of the environmental impact in various fields. However, this approach is not employed for the assessment of the environmental impact at the planning or design stages of construction projects. The reason is that the features of construction projects cannot entirely provide the full information required for performing LCA until the design has been complete. This study performed LCA of concrete girders and estimated the properties and basic unit quantity of the environmental loads. Our findings support that environmental impact assessment based on LCA should be performed at the planning or design stage when no full information is still available. Moreover, we propose an environmental impact index based on the input cost and the occurrence rate of environmental loads as an environmental performance indicator of concrete girders. This methodology is expected to induce the paradigm to transit from the existing environmental impact assessment methodology based on input resource amounts to the environmental impact assessment methodology in economic perspective considering the characteristics of construction projects.
... According to this, life cycle assessment is a technique for estimate the potential environmental aspects of a product or service, by taking inventory of the relevant data, evaluating the impacts and analyzes the results [7]. However, there are several LCA studies in road construction [5], [8]- [10], in the case of infrastructure facilities, there is no integrated LCA methodology. LCA is generally limited to materials, construction vehicles and engine alternatives. ...
To measure the environmental impacts, life cycle assessment techniques appeared. The paper presents the SimaPro, which is one of the most widely, used software for life cycle assessment. Studies indicate that environmental impact can be considerably reduced in the planning and the design stages, if sustainability is evaluated. Therefore, a system of objective measurement is inevitable. Nowadays, numerous road rating systems exist and are used around the World. Taking into consideration EU directives, employing a rating system in Hungary has great importance. Therefore, paper presents an action plan to develop a domestic sustainable evaluation tool for road construction.
... D'abord focalisées sur la comparaison entre chaussées aux liants hydrocarbonés et aux liants hydrauliques (Häkkinen, Mäkelä et Valtionteknillinen tutkimuskeskus, 1996 ;Horvath et Hendrickson, 1998 ;Roudebush, 1999 ;Berthiaume et Bouchard, 1999), la question du développement et de la qualité des données d'inventaires environnementaux s'impose rapidement comme primordiale (Stripple 2001). C'est aussi à cette époque qu'un guide d'application de l'ACV au secteur automobile est publié par le Conseil Européen pour la R&D automobile (EUCAR) (Ridge 1998) (Nisbet et al., 2001 ;Park et al., 2003;Treloar, Love et Crawford, 2004 ;Zapata et Gambatese, 2005 ;Athena Institute, 2006 ;Chan 2007;Muga et al., 2009 ;Huang, Bird et Heidrich, 2009 ;White et al., 2010 ;Abdo 2011). D'autre part, des ACV de véhicules automobiles sont réalisées par des constructeurs (Schweimer et Levin 2000 ;Volkswagen AG 2008a, 2008b (Inyim et al. 2016). ...
... Many studies have been conducted to apply the LCA in the construction field (Jun, 2007). The LCA can evaluate the entire range of SOC facilities including harbors, dams, bridges, and roads, and therefore, currently offers the most reasonable methodology for estimating the environmental impact resulting from construction (Yue et al., 2008;Treloar et al., 2004). ...
To encourage environmentally friendly construction, reasonable data (such as Life-Cycle Assessment (LCA) performance results) that determines the potential environmental impact of construction works should be provided during the decision-making process in the early design phase. However, it is difficult to acquire the data necessary to carry out an LCA prior to completing the design, so LCA is not typically used in the design phase. In order to overcome this limitation, this study developed an LCA-based environmental impact estimation model that uses the information available during the design phase to provide an estimate of the environmental impact of an earthwork-type road project. Earth, drainage, and pavement were defined as major work categories that have a significant effect on environmental impact and were accordingly made the focus of the developed model. The impact of the earthwork category was determined by case-based reasoning methodology, and the work quantity methodology using standardized cross sections was used to determine the impact of the drainage and pavement categories. Test results indicate that the proposed model provides a mean absolute error rate of 8.20%, demonstrating that it is valid and offers significant benefits for the early project estimation of environmental impact.
... Those research on early CO 2 emissions impacts on road construction have mostly focused on components of a road project not an entire road project, especially on comparison analysis on different surface structures (Park et al., 2003;Treloar et al., 2004Santero et al., 2013 and pavement material use (Horvath and Hendrickson, 1998;Stripple, 2001;Huang et al., 2009). Later, the research highlights extend to recycled materials, waste materials reuse and new materials used on the pavement (Huang et al., 2009;Chowdhury et al., 2010;Anastasiou et al., 2015) and on earthwork (Celauro et al., 2015;Barandica et al., 2013). ...
Carbon dioxide (CO2) emissions mitigation from transportation infrastructure construction activities is regarded as one of the potential pathways to deal with climate change. Aiming to assess the magnitude of CO2 emissions associated with freeway infrastructure construction activities and identify primary emissions sources in mountainous area, this study firstly assessed life cycle CO2 emissions of an entire freeway project in mountainous area in China, including pavement, bridge, tunnel, intersection, traffic safety facilities and temporary works into the system boundary. The results show that CO2 emissions related to road segment are one magnitude lower than that of bridge and tunnel. In addition, negligence of intersection, traffic safety facilities and temporary works could underestimate 4% of total CO2 emissions of the freeway project. CO2 emissions distribution of the different types of materials and equipment distribute as the similar Pareto Principle, which reminds that definition of system boundary could focus on the few of inputs that matter on the aspects of data limited, rough estimation and comprehensive understanding of environmental impact. Findings of this study could offer transport agencies more comprehensive references to understand the contribution of freeway infrastructure construction activities in the mountainous area to climate change, and provide decision makers insights to take measures in the planning phase, particularly in the construction phase in terms of equipment selection, construction design, and construction materials design.
... This method allows a comprehensive measurement of carbon emissions (Williams et al., 2009) and is considered to be more accurate (Crawford, 2008). Using this method requires less time and cost, and the data can be obtained from government or industry platforms (Treloar et al., 2004)Error! Reference source not found.. ...
The construction industry is characterized by high-energy consumption and intensive-carbon emissions. With the promotion of energy-saving technologies in buildings combined with concerns for global-warming, there has been a gradual shift in energy conservation requirements from the operation stage to the construction stage. This shift is primarily delivered through the use of improved materials and technologies implemented during the building construction stage. Building industrialization is an innovative construction approach that has experienced rapid up-take in China. The use of prefabricated components in building construction is now a key feature of the building industrialization process, and thus warrants greater attention in terms of its energy consumption and carbon emission. This paper utilizes a process-based method to assess carbon emissions during the prefabrication manufacturing process in offsite factories. A life cycle assessment is applied to a case study concerning a prefabricated concrete interior wall board. Carbon sources during the manufacturing process is identified and the carbon emissions are quantified using a factor method. The results show that carbon emissions from the interior prefabricated concrete wallboard of volume 0.609m³ is 427 kg, with the vast majority of the emissions originating from building materials, at 96.2%. The carbon emissions from electricity consumption constitutes 3.65%, and that from workers make up only 0.16%. The findings of this study offer a carbon emission benchmark for building industrialization, which in turn serve as a solid data foundation for carbon assessment of prefabricated buildings in China.
... One of the primary challenges in real-world application of any LCA methodology is defining the scope, source and quality of the LCIA inventory data that needs to be collected for identifying the environmental burden generated across the different stages of a road network asset. Industrial confidentiality related to upstream case-specific historical data and the cost of gathering high quality and detailed LCA data for a construction project (Treloar et al., 2004) may be challenging for any road agency in applying LCA for decisionmaking process. On the other hand, uncertainties in the collected LCIA data may be detrimental to the calculated environmental performance of the different alternatives for the road asset case study being analysed by the road management agency. ...
Life-cycle management of road network projects traditionally emphasise material production and construction stages, with less attention given to usage stage and functionality improvement. Increasingly there is a need to address: inconsistencies in cost attribute selection; adjusting for uncertainties and costs; clarifying system boundaries; data sources; functional units and regional or temporal applicability of life-cycle frameworks. The current study focuses on a critical literature review of life-cycle cost analysis (LCCA) and life-cycle assessment (LCA) research published in the last decade (post 2008) towards identification of research gaps. Accurately analysing all life-cycle stages, feedback loops, future cash and resource flows, and interlinking performance with overall sustainability can aid the decision-making process towards sustainable alternatives for constructing new, or rehabilitating existing roads. This review finds that the use of recycled materials, base/sub-base stabilisers and asphalt binder replacement has the potential of energy saving (≥34% or 3.1 TJ), mitigating landfill disposal issues, and greenhouse gas load reduction (≥34.5% CDE). Lack of real world LCCA-LCA application and stakeholder prejudice against recycled material usage are addressable by better stakeholder (decision-makers and road users) engagement via a social component. The proposed enhancements identified in this study can increase LCA/LCCA attraction to policy-makers, planners and users and ultimately ensure a more sustainable asset.
... Several international studies on road infrastructure and LCA have utilized hybrid LCA, an analysis whereby LCA and input-output analysis (IOA) is combined (Chester & Horvath, 2009;Rodríguez-Alloza, Malik, Lenzen, & Gallego, 2015;Treloar, Love, & Crawford, 2004). IOA is an assessment method that calculates emissions shares on entire sectors of the economy and maps the value exchanges (in monetary terms) between these sectors. ...
Effective and efficient road transportation in Norway is a continuing concern. The growth in population and the continuing need for better infrastructure to serve this population propel the growth of road construction. Roads will continue to occupy the most prominent place in the Norwegian transport puzzle as the most commonly used form of transport by both people and goods today. The quadrennial National Transport Plan guides large scale transport planning in Norway and has recently included national CO2 emissions reductions targets for all new road infrastructure and construction. At the same time, the investment in Norwegian road infrastructure is at an all-time high, as authorities seek to modernize the Norwegian road network through megaprojects, such as the Ferry Free E39. This increase in investment and construction will inevitably lead to an increase in resource consumption and emissions without wise planning decisions, smart material choices and the use of sustainability assessment tools. Life cycle assessment (LCA) is one such tool that is used to measure environmental impacts of infrastructure and construction processes, including climate change emissions. To what extent LCA is already used in Norwegian road planning and what lessons can be learned from earlier studies that can apply to today's megaprojects are of interest to road builders if emissions reduction goals are to be taken seriously. The purpose of this paper is to determine the state-of-the-art of Norwegian road LCA and determine in which direction Norwegian research should move. The first section of the paper looks at the overarching conditions for Norwegian road construction in terms of planning, trends, and policy; the second section looks at relevant LCA studies on Norwegian roads, while the third section looks at possible research paths which should be followed to better assess and reduce the impacts of emissions in road infrastructure.
... Nevertheless, equivalent carbon dioxide (CO2) can be reported as a same criterion in environmental evaluations, showing the global warming effects and having a widespread effect makes its priority higher than other criteria. (Santero 2010, Chan 2007, Egbu et al. 2009, White et al. 2010, Häkkinen and Mäkelä 1996, Treloar et al. 2004 Among different methods for evaluating uncertainties, Mont-Carlo simulation as a probabilistic method has been used more, but the need to a large amount of calculations, sensitivity to probability distribution functions and the need of assuming relation between all inputs are some disadvantages of this method. On the other hand, Fuzzy logic may be viewed as an attempt at formalization/mechanization of two remarkable human capabilities: First, the capability to converse, reason and make rational decisions in an environment of imperfect information, and second, the capability to perform a wide variety of physical and mental tasks without any measurements and any computations (Ferson 2002, Zadeh 2008). ...
Sustainable development is a challenging issue which has been heavily concerned during recent decades. A considerable investment of general budget of each country is annually allocated to highway projects. Therefore, a minor improvement in this section can lead to major efficiencies in the way of sustainable development. A number of research has been conducted to evaluate the environmental effects of highway projects in a long-term horizon. Existing methods often model the projects in a deterministic approach. But considering uncertainty associated with every project compels using non-deterministic methods. While much of the basic information required for human decisions are possibilistic rather than probabilistic in nature and fuzzy set theory provides a basis for the theory of possibility. Fuzzy method as a potent tool for uncertainty-based assessment, not only covers the uncertainties, but also addresses shortcomings of probabilistic methods. In the absence of precise and complete information, fuzzy set theory is better capable of extracting and representing the required information from experts by effectively capturing their linguistic and subjective evaluations. The method presented in this paper considers the uncertainties associated with traffic demand and pavement performance by fuzzy set theory and provides a tool to compare different strategy alternatives for performing pavement project by an innovative life-cycle assessment (LCA) method. The presented LCA tool quantifies environmental effects of each construction alternative in two terms of “Global Warming” and “Energy Consumption”. Finally, the presented approach is implemented in a highway project, as a case study. The results indicate that the significant effect of pavement performance on global warming impacts and energy consumption, emphasizing that pavement performance should be taken into consideration in evaluation of different pavement construction strategies.
... In this sense, application of LCA to infrastructure decisions appears to be of paramount importance. Till date, many LCA studies have been conducted about infrastructure construction [3][4][5][6][7], transportation system [8][9][10], wastewater treatment system [11][12][13][14], and waste treatment systems [15][16][17][18][19]. In these studies, LCA was used to evaluate the environmental performance of several infrastructures and compare various waste treatment options to determine the optimum waste management strategy (e.g., incineration, recycling and landfill) which have different performance characteristics. ...
A life cycle impact assessment was applied in an industrial waste incineration plant to evaluate the direct and indirect environmental impacts based on toxicity and non-toxicity categories. The detailed life cycle inventory of material and energy inputs and emission outputs was compiled based on the realistic data collected from a local industrial waste incineration plant, and the Korean life cycle inventory and ecoinvent database. The functional unit was the treatment of 1 tonne of industrial waste by incineration and the system boundary included the incineration plant and landfilling of ash. The result on the variation of the impact by the unit processes showed that the direct impact was decreased by 79.3, 71.6, and 90.1% for the processes in a semi dry reactor, bag filter, and wet scrubber, respectively. Considering the final impact produced from stack, the toxicity categories comprised 91.7% of the total impact. Among the toxicity impact categories, the impact in the eco-toxicity category was most significant. A separate estimation of the impact due to direct and indirect emissions showed that the direct impact was 97.7% of the total impact. The steam recovered from the waste heat of the incineration plant resulted in a negative environmental burden
... Several researchers have already investigated the environmental impacts of roads (e.g. Huang et al., 2009;Santero et al., 2011aSantero et al., , 2011bSantero et al., , 2011cTreloar et al., 2004), while others have linked material use, energy use, greenhouse gas emissions, and water use for buildings for the City of Melbourne (Stephan and Athanassiadis, 2017). We are now able to build on their findings to create a comprehensive understanding of the material and energy requirements to construct and operate roads. ...
Recent years have seen a growing interest in the potential for a more circular economy and the application of material flow accounting to increase knowledge on materials accumulating in in-use stocks. This study assesses the dynamics of stocks and flows related to road networks, which are a significant destination for recycled construction and demolition waste.
We develop a bottom-up stock-driven model to assess long-term inflows, outflows, and materials accumulated in roads to assess requirements for construction minerals of the road network in the United States. We estimate material requirements using the expansion of the transport network as a driver, and scheduled maintenance and technological coefficients from engineering literature to assess input and output flows. We apply the model to historical data for the United States road network from 1905 to 2015 and show that the current material stock of construction minerals in the road network of the United States is 15.1 billion tonnes, growing 21-fold since 1905.
During the 20th century, the material requirements of road construction have declined from 35% to 15% of economy-wide material consumption of non-metallic minerals in the United States. The share of roads in economy-wide in-use stocks has also declined from 17% to 13%. This shows that roads, once established, remain in place and most material flows are due to extending and refurbishing them, while the construction of completely new roads makes up a much smaller part of the material flows related to the road network.
... In this sense, application of LCA to infrastructure decisions appears to be of paramount importance. Till date, many LCA studies have been conducted about infrastructure construction [3][4][5][6][7], transportation system [8][9][10], wastewater treatment system [11][12][13][14], and waste treatment systems [15][16][17][18][19]. In these studies, LCA was used to evaluate the environmental performance of several infrastructures and compare various waste treatment options to determine the optimum waste management strategy (e.g., incineration, recycling and landfill) which have different performance characteristics. ...
This study provides a holistic list of factors that affect highway sustainability (HWS) and determines the most significant factors throughout the triple-bottom-line of sustainability. Previous studies analyzed many factors related to sustainability performance in highway projects during their life cycle, whereas the social sustainability aspects were commonly ignored. In addition, there is imperative to consider the Sustainable Development Goals (SDGs) of highway projects in local and global future visions. On the other hand, the infrastructure rating systems specified different thresholds to achieve sustainable highways. Thus, this study analyzed published articles, SDGs, and infrastructure rating systems to extract the most important factors affecting HWS. A content analysis was conducted to specify the most relevant publications in HWS, which are strongly related to the research keywords. According to the content analysis, 150 articles out of 6,422 were selected for further investigation. Social Network Analysis (SNA) analyzed and ranked 224 factors that were extracted from the aforementioned sources to determine the factors of utmost importance. We found that 78 factors out of 224 are of paramount influence on HWS. Finally, the evaluation of the most widely used infrastructure rating systems revealed a shortage in the common factors affecting the HWS.
In recent years, there has been a sharp rise in the number of life cycle assessment (LCA) studies related to road pavements and road infrastructures. The main aim of this study is to perform a critical analysis of various studies undertaken so far to examine goals, scopes, impact categories, life cycle phases, methods and approaches, and limitations. A total of 67 LCA studies reported in literature were analysed and categorized into four categories viz. flexible pavement; rigid pavement; flexible and rigid pavement; and road infrastructure. The analysis revealed that 80% of the studies were carried out in developed countries while just 20% of studies were from developing countries. Most of the road pavement LCA studies (∼76%) considered material and construction phase and assessed the impacts in terms of only two impact categories viz. global warming potential and energy demand. Only 10-15% of studies considered a wide range of impact categories and used commercial software such as GaBi and SimaPro for impact assessment. 19 studies were on flexible pavements, 4 on rigid pavements, 30 on both flexible and rigid pavements and 14 on infrastructure. Bridges, tunnels, drainage, lighting, and road marking were the major components of road infrastructure studied while other road infrastructures such as culverts, toll plazas, and vehicle underpasses were not included. Majority of the studies depended on secondary or background data for the development of life cycle inventory. Out of 67 studies, only 18 studies performed the sensitivity analysis while only 6 studies carried out uncertainty analysis. There is a need for inclusion of all supporting infrastructures along with road pavement, and also for paying greater attention to sensitivity and uncertainty analysis in studies pertaining to the transportation sector. During construction phase, no LCA study considered the important impacts due deforestation, defragmentation, restriction of free wildlife movement etc. Hence, future LCA road studies must evaluate the negative consequences of these as well as integrate social and economic impacts via Multi-Criteria Decision Making to make LCA a robust decision-making tool for sustainability.
Reducing environmental impacts in transport motivates many studies to offer more sustainable freight services. However, most methodologies focus on impacts from fuel consumption, and approaches trying to integrate other transport components have not facilitated its application to actual and specific transport services. In this study, we present a harmonized approach to address the transport services with a holistic way to increase the knowledge about hotspots of the transport sector based on the life cycle assessment methodology. In this framework, vehicle manufacturing, fuel production, and infrastructure construction are the key transport components around the traffic process. Besides fuel usage, the operation and maintenance of vehicles and infrastructures are also included. We developed a tool to create the life cycle inventories for each transport component to be applied to specific transport services in any location with a comprehensive view and low uncertainty in the results. This approach was applied to road-freight services in Colombia, Malaysia, and Spain. The main results showed the nature and origin of the environmental impacts, which are highly influenced by the emissions control technologies, road characteristics, and traffic volume. The contribution of atmospheric pollutants per tonne-km can decrease by a quarter when Euro VI trucks on highways instead of conventional trucks on single-lane roads are used. However, these contributions are highly affected by fuel production due to the origin of biofuels. The proposed methodology provides relevant information to estimate transport impacts in the life cycle assessment of products with superior precision and identify strategies for systemically improving sustainability.
This study aims to integrate sustainability indicators into the traditional assessment of network-level pavement maintenance budget scenarios. A conceptual framework is developed based on a multi-attribute method by systematically considering road conditions, economic, environmental, and social sustainability. A case study is then adopted to demonstrate the usefulness of this framework. Out of eight network-level pavement maintenance budget scenarios, the 85M plan (representing an annual maintenance budget of AUD$85M) is selected as the optimal solution in an initial experiment in which equal weights are allocated to the four attributes. In an additional experiment with 1000 sets of randomly assigned weights, the 85M plan was also selected as the optimal option for 596 trials. The proposed framework provides a straightforward method for road agencies to select the optimal network-level pavement maintenance budget scenario or obtain preliminary insights when the precise weight of each sustainability attribute cannot be accurately obtained.
As a kind of low strength aggregate, the mechanical properties of sandstone can hardly meet the requirements of current specifications for highway concrete materials. In this study, oblique prestressing technology is used to overcome the shortcomings of the mechanical properties of sandstone and the construction process. Sandstone concrete is used in the road base, and a finite element model of sandstone concrete is established. Through the concept of the whole life cycle of concrete materials, the structure of sandstone concrete composite pavement is optimized, and the objective function of the life cycle of composite pavement based on sandstone concrete materials is proposed. When using 5 cm rubber asphalt concrete single-surface layer and 18 cm sandstone concrete obliquely prestressed concrete base layer, the objective function value is the smallest, indicating the best optimization result. These results provide a basis for the later application of sandstone concrete materials.
Ever since the term sustainability was firstly coined by the Brundtland Commission in 1987, this concept has become a key goal in assessing the impacts of transport policies, plans and projects. In the context of the book, this chapter conducts a review of the main academic and practical achievements conducted up to date regarding sustainability appraisal of transport undertakings. The chapter begins with an analysis of the key aspects embedded within the term “sustainability,” as well as the evolution of the concept over time. It continues with a description of some of the methods specifically designed to assess sustainability—such as rating systems, models and frameworks—from which it is concluded that they are rather incomplete. It continues with an analysis of the missing aspects that conventional appraisal methods—such as cost-benefit analysis, multi-criteria decision analysis or environmental impact assessment methods—lack to rightly address the requirements of sustainability assessment. After that, the chapter suggests a methodology, consisting of a set of steps, to appraise sustainability of transport projects. The chapter finalizes with key reflections about future challenges to improve sustainability assessment.
Adaptive reuse is an alternative to a building’s end-of-life where its function is extended to serve another purpose. Many studies suggest that adaptive reuse is more sustainable than typical demolition and new construction in terms of environmental, social, and economic impacts. However, these claims are qualitative in nature and are limited to analyses at the project scale. This paper presents a methodology based on Input-Output (IO) models for examining economic and energy impacts of substituting adaptive reuse for new building construction. An IO model for the Province of Ontario, Canada, was developed to study the impacts of adaptive reuse building construction. The building construction industries’ intermediate inputs and final demands were altered in the Ontario IO model to reflect changes in the supply and demand of adaptive reuse buildings in the construction industries. A basic scenario represents the situation where only the building’s superstructure and substructure are reused. The basic scenario was then extended to reflect the reuse of internal non-structural components. The Ontario IO model examines impacts to gross domestic product (GDP), industry outputs, employment and energy use (including rebound effects from household consumption changes). It was found that adaptive reuse building construction may benefit Ontario’s economy and reduce energy consumption under certain combinations of changes in supply and demand. The desired domain of adaptive reuse construction, where energy use decreases, while GDP and employment increases, is discerned for both the residential and non-residential building construction sectors in Ontario. This methodology may be used for other regions for which IO information exists.
Although pavement maintenance and rehabilitation (M&R) techniques are usually
examined in economic terms, there is a growing need to address their environmental footprints.The objective of this study is to assess the environmental impacts of M&R techniques. LCA can help in the decision-making process of selecting suitable maintenance techniques based on their environmental impacts. This study investigates: patching, rout & sealing, hot in-place recycling, and cold in-place recycling. Global warming potential, acidification potential, human health particulate, eutrophication potential, ozone depletion potential and smog potential are estimated as environmental impacts for each maintenance activity. Materials, equipment use (for construction
and M&R), and transportation were the main elements considered. A sensitivity test is performed to identify the significant factors for the LCA. The study concluded that GWP was the most important impact category. Rout & sealing and CIR produced the lowest GWP emissions. Notably, pavement patching and HIR showed significant detrimental environmental impacts.
In response to increasing environmental pressure due to climate change, the global community and the Norwegian government have agreed to reduce emissions of greenhouse gases. The government-run Norwegian Public Roads Administration (NPRA) have been tasked with finding ways to drastically reduce their carbon dioxide emissions from road construction and maintenance by the year 2030. In response, NPRA has invested in research and begun the process of developing policy to promote the uptake of cleaner technologies, fuels, materials and processes. This thesis will discuss the solutions and strategies that NPRA can follow to reduce their emissions by presenting a series of articles that focus on the use of life cycle assessment models to calculate emissions of road infrastructure in the early planning phases and by discussing the implementation of emissions reductions policies. The results of this study have shown the use of models can be helpful for calculating emissions but that these models must be sufficiently robust and simple to use in order to be useful during road planning. (ISBN 978-82-7117-947-2)
Motivated by the lack of a systematic analysis of the use of life cycle assessment (LCA) to estimate the environmental impacts of roads, this study conducts a critical review to examine the methods, common practices, limitations, and underlying reasons, so that future directions can be recommended. In this work, 94 papers that adopt LCA methods to assess the environmental impacts over the whole life cycle of roads were analyzed. The results demonstrate that the process-based LCA remains the most commonly adopted LCA method; however, the hybrid LCA has been gradually recognized. After examining the goal and scope definition, life cycle inventory, life cycle impact assessment, and life cycle interpretation of these studies, it was found that the current LCA applications in roads face limitations owing to the inconsistent and inappropriate selection of the functional unit, limited consideration of the maintenance and repair, use, and end-of-life phases, limited reporting of data sources, lack of standardized impact assessment procedures, and lack of sensitivity and uncertainty analyses. These limitations can be attributed to the lack of a standardized LCA procedure for roads. There is also a lack of LCA studies focusing on network-level analysis, which may restrict the use of LCA to assist policy making in road planning and management. In addition, the time effect is rarely considered to reflect the dynamic changes of environmental impacts over the project life cycle. Therefore, future directions are recommended accordingly. Improvements in these areas are expected to generate more reliable LCA results for informed decision making.
(50 days's free access for this article: https://authors.elsevier.com/a/1a1Vc4rgZicu2-)
While many pavement life cycle assessment (LCA) studies have been performed over the last decade, one of the most important advances and challenges is quantifying the impacts of various components during the use phase of pavements. The goal of this research is to understand the role of the use phase, particularly pavement-vehicle interaction (PVI), in pavement LCAs, and how use phase impacts vary by context (i.e., for specific climates and traffic levels).
We have performed comparative pavement LCAs on two pavement design alternatives for multiple scenarios that encompass a range of locations and traffic levels. The pavement LCA model is probabilistic and the use phase element includes excess fuel consumption from both deflection-induced and roughness-induced PVI. Results from the scenario analysis demonstrate that the use phase can contribute up to 78% of a pavement's life cycle environmental impact and that PVI is the predominant element in the use phase of high-volume roads. Scenario analysis results also indicate that the use phase contributions are highly context sensitive to traffic volume, climate, and vehicle speed. This work contributes to the understanding of the context-dependent use phase impact and reinforces the importance of uncertainty quantification in comparative pavement LCAs.
The construction industry including infrastructure construction, affects the environment due to the use of a considerable amount of resources and energy. The management of the environmental effect of dams for agricultural reservoirs is especially important in South Korea because of their large scale and nationwide distribution. The objective of this study is to propose an assessment method for evaluating life cycle carbon dioxide emissions associated with fill dams and to characterize carbon dioxide emissions to use in effectively addressing the environmental concerns for infrastructures. A total of four dams were selected for the research, and the material production, use of equipment and transportation were considered as the causes of carbon dioxide emissions at the dams. The effective life cycle of a fill dam was assumed to be 100 years. The results of the research indicated that the total amount of carbon dioxide emissions were different for each dam according to their characteristics, and the results showed that the dam size is the primary cause. In addition, the carbon dioxide emissions increased as the period of use increased, and a rapid increase was indicated in 40–50 years interval of the dams’ use periods because the repair activities were concentrated in those years. Materials were the biggest contributor in the amount of total carbon dioxide emissions at all four sites and the ratio of carbon dioxide emissions caused by materials was higher than any other factors in most processes. There was little difference in the proportion of carbon dioxide emissions for each process in the total carbon dioxide emissions for the four sites. Most carbon dioxide was emitted during repair activities at the two largest dams. Activities associated with the construction process was the major source of carbon dioxide emissions at the two other dams. This difference in process carbon dioxide emissions was the result of the difference in the construction scale for the embankment elevation. The assessment method that has been proposed in this study reflects the characteristics of fill dams, and the result of estimating carbon dioxide emissions indicates that we are able to reduce carbon dioxide emissions in the life cycle of fill dams by selecting the construction materials and the repair methods with a low carbon dioxide emissions.
Climate change and greenhouse gas (GHG) emissions have attracted much attention for their impacts upon the global environment. Initiating of new legislation and regulations for control of GHG emissions from the industrial sectors has been applied to address this problem. The transportation industries, which include operation of road pavement and pavement construction equipment, are the highest GHG-emitting sectors. This study presents a novel quantification model of GHG emissions of pavement construction using process-based analysis. The model is composed of five modules that evaluate GHG emissions. These are: material production and acquisition, (2) material transport to a project site, (3) heavy equipment use, (4) on-site machinery use, and, (5) on-site electricity use. The model was applied to a hypothetical pavement project to compare the environmental impacts of flexible and rigid pavement types during construction. The resulting model can be used for evaluation of environmental impacts, as well as for designing and planning highway pavement construction.
The application of Life Cycle Assessment to road pavements has been evolving over the last years, receiving a growing interest from the academic sector and from governmental and non-governmental institutions and organizations. However, the complete introduction of this approach in the asset management decision making process is not possible yet, due to an incomplete understanding of the impact of some relevant phases and components of a road pavement LCA, such as the work zone impact during maintenance events and the rolling resistance in the use phase. The first one refers to the additional congestion and traffic delay in an area of a trafficway interested by construction and maintenance activities. The road pavement rolling resistance is the energy loss due the pavement-vehicle interaction (PVI) and it is affected by the tire properties and by the pavement surface condition. The introduction of the Carbon Footprint/LCA approach in highway asset management, as a decision making tool, requires a deep understanding of all the phases of the life cycle of a road and of the impact of the selected methods and assumed parameters to model them. This thesis provides a review of the main models used to describe the influence on the vehicle fuel consumption - in terms of CO2 emissions - of the work zone during maintenance activities and the rolling resistance during the use phase and investigates the potential impact of these models and of some input parameters on the LCA results. The study was applied on two different UK road sections, characterized by different traffic volume, maintenance activities and design. The impact of the work zone during maintenance activities was explored, comparing the CO2 emissions obtained from two generally applied models in Life Cycle Assessment studies (LCAs) with different level of sophistication: the microsimulation model Aimsun and the macroscopic analytical/deterministic method described in the Highway Capacity Manual (HCM), which is based on the Demand-Capacity (D-C) model and the queue theory. In these models, the traffic volume, the Traffic Management (TM) strategy, the Emission Factor (EF) model and the network boundary are input variables that potentially generate uncertainty in the results and their impact was investigated. The impact of the rolling resistance, due to the pavement surface properties, was assessed with two different models provided in literature and a sensitivity test was performed on some significant input variables, namely the pavement deterioration, the traffic growth and the selected EF. The results obtained in this research have shown that the models adopted to estimate the vehicle emissions for both the work zone impact and the rolling resistance components have a significant influence on the LCA results. Therefore, the selection of the model to assess the impact of these components need to be accurate and appropriate. To assess the work zone impact during maintenance events, the selection of the traffic and emission models should be based on the study objectives and on the available resources. The assessment of the impact of the rolling resistance on the vehicle emissions requires the development of models to estimate the deterioration rate of the pavement surface properties over time and models to link them to the rolling resistance energy loss and to the vehicle emissions. Although currently there are few models available in literature, they are affected by site specific elements and are not suitable for all geographical locations. In the UK, there is currently a lack of general pavement deterioration models able to predict the change of unevenness and texture depth over time and the relationship between them and the rolling resistance and the fuel consumption. This must be corrected before pavement LCA studies can be extended to the use phase. The selected model is not the only source of uncertainty in the assessment of these components. In fact, the analysis of the work zone impact and of the rolling resistance requires several methodological assumptions that, as shown in this study, can have a relevant impact on the results, generating a high level of uncertainty. The results obtained from the work zone impact analysis are sensitive to all the input variables taken into account in this study: the traffic growth, the TM strategy adopted, the EF model and the extent of the road network assumed to be impacted by the work zone. For the rolling resistance, if the deterioration rate of the pavement surface properties is a significantly sensitive parameter, the traffic growth and the EF/fuel efficiency predictions, combined to predict future vehicle emissions, have a relatively small effect because they cancel out to a large extent. However, changes in predicted future traffic levels or EF could change this result and should be kept under review. These research outcomes highlight the importance of incorporating uncertainty into pavement LCA. The reliability and accuracy of an LCA is affected by the reliability of the methodologies and models adopted. LCA results should not be presented as ’single figure’ absolute values, but rather considering a range of values to reflect the uncertainties and variability that lie behind them.
The construction industry involves heavy machine usage which contributes a large amount of air pollutant emissions, including greenhouse gases (GHG), particulate matter, and diesel exhaust. These emissions cause serious environmental issues and climate change. This paper provides a systematic review of the existing research efforts and challenges on measuring air pollutant emissions and assessing the environmental impact from the construction industry. The advantages and disadvantages of various methodologies used in measuring emissions and assessing the environmental impacts of construction are compared. The existing air dispersion models used in the construction field are also reviewed. The results from the review help to identify cost-effective environmental planning and management processes. Consequently, future trends towards improving existing emission assessments and management processes are put forward, and a new framework is proposed for the effective assessment and management of air emissions and environmental impacts from the construction industry.
In China, the building sector, as a pillar industry of China’s modern economy, plays a vital role in generating carbon emissions, which is responsible for about 40% of the national total carbon emissions. To provide insights into the current carbon assessment practice of buildings in China, this chapter conducted an overview of current policies and industry initiatives promulgated for building carbon reduction and approaches currently being used to assess embodied carbon of buildings in China. To address the issues that are related to quantify embodied carbon of buildings under different scales, this chapter introduces assessment approaches and uncertainty analysis methods from both the macro and micro perspectives. The results show that the current focus of China is still on the buildings’ operational carbon reduction rather than the embodied phase. Such policy orientation does not match the increasing role of embodied carbon reduction in the creation of sustainability in the building sector. In China, the single-region input-output analysis (SRIO), multiregional input-output analysis (MRIO), and structural path analysis (SPA) are commonly used to assess embodied carbon at the macro level, while the process-based and hybrid LCA models are dominant in micro-level analysis. Although the process-based approach is most frequently used for embodied carbon assessment of buildings, a clear trend can be observed that the relevant studies gradually shift their focus from process-based individual cases to a more hybrid and macro sense in China.
Life cycle assessments (LCAs) are used to evaluate the environmental impacts attributable to products and processes. For construction projects, LCAs can be used to assess the pollution associated with the manufacture of building materials for the construction process. Despite the reliability of traditional LCA data, many upstream processes are excluded, which adversely affects overall reliability. Input-output analysis is systemically complete, but is subject to inherent errors when applied to the LCA of specific products. Analysis of an input-output LCA model provides a basis for more informed decision making regarding processes which can be ignored during the collection of traditional LCA data. This paper proposes a hybrid LCA method for construction in which national input-output data fill those 'gaps' not accounted for by traditional LCA data. Regardless of the level of detail at which data are collected, LCAs can now be performed at similar overall levels of framework completeness.
The purpose of this study is to quantify the total amount of energy consumption and CO2 emission caused by the construction, operation, maintenance, and renovation of office buildings in Japan. In order to quantify the life cycle energy consumption and CO2 emission of a building, it is necessary to obtain an estimate of the total quantity of domestic products and services used directly or indirectly (including the repercussion effect of the economy) during the life cycle of the building. The Input/Output (I/O) Table of Japan is used to calculate the total domestic product and then energy consumption and CO2 emission are estimated by using energy consumption and CO2 emission data for unit production of various categories of industries.
The building environmental assessment field is reviewed since it first came into prominence in the early 1990s. Key limitations of existing building environmental assessment methods are identified and the emerging importance of issues such as sustainability, life-cycle assessment, globalization and standardization are discussed. The author provides a constructive direction for emerging ‘second generation’ building environmental assessment methods and protocols. This includes a standardization of environmental assessment methodologies; a common, generalized framework which allows for adaptation of specific and changing explicit criteria and an increased emphasis on building performance over time. Le champ d'estimation écologique du bâtiment est passé en revue depuis le début des années 1990, époque de sa première apparition remarquée. Les limitations-clés des méthodes d'estimation écologique des bâtiments existants sont identifiées, et l'importance manifeste de questions telles que viabilité, estimation de cycle de vie, mondialisation et standardisation est examinée. L'auteur offre une direction constructive de mise au point de méthodes et comptes-rendus d'estimation écologique de “seconde génération” naissante. Celle-ci comprend une standardisation des méthodologies d'estimation écologique, un cadre généralisé commun qui tient compte de l'adaptation de critères spécifiques variables explicites, ainsi qu'une importance accrue conférée aux performances des bâtiments dans le temps.
ISO 14000 has been developed as a new international standard series for promoting environmental protection and sustainable development. Since the introduction of ISO 14001 in September 1996 it has attracted great attention from organizations in various industries. ISO 14001 specifies the requirements and procedures for establishing an environmental management system. An increasing number of organizations from various industrial sectors have actively participated in implementing this new standard. However, very few construction companies – for example, in Australia – have actively pursued certification to this standard despite having an obligation to implement it, as the services and products they produce directly impact the environment. By reviewing the strategic issues posed by the entire family of ISO 14000 standards, this paper analyses its relevance to construction and the difficulties and problems that may be encountered in their implementation. A framework for implementing the standard in construction companies is proposed. It is suggested that the adoption of ISO 14000 by construction companies may enable them to improve their environmental performance as well as the built environment, which in turn will contribute to sustainable development.
Building designers are increasingly concerned about the environmental impact of building projects. Coupled with this is the heightened demand of client organizations for environmentally ‘friendly’ buildings. Commercial buildings are often the most tangible expression of an organization's values; values it wishes to convey to employees and customers. The complexity of issues influencing a building's ‘greenness’ does present a problem for the designer. To address this problem the Building Research Establishment (BRE) produced an assessment framework entitled the Building Research Establishment's Environmental Assessment Method (BREEAM). The purpose of this method is to monitor designs and raise the awareness of designers to environmental issues. It is not intended for use as a comparative basis for competing designs. Instead, it provides technical guidance on the issues which need to be addressed in an environmental assessment. The author considers that this framework should be extended to assess explicitly the values of the client and the priorities of the environmental community.The methodology advocated in this paper is based on multi-attribute utility theory (MA UT). This allows the combining of information obtained from experts, with values elicited from the eventual building users and owners. It provides a tool to assist the designer in the briefing stage as a negotiation mechanism, and at the proposal stage as a device for advocacy.
Embodied energy is defined as the energy consumed in all activities necessary to support a process, including upstream processes. The Leontief inverse input–output (IO) matrix gives results that are practically complete, because of the aggregation of direct and indirect requirements, but which are also unreliable, because of inherent assumptions. Although accurate for the system boundary considered, process analysis results are incomplete relative to the pure IO system boundary. Attempts to combine process and IO analysis tend to be based on process analysis data. The system boundary is still significantly incomplete—although not as incomplete as for pure process analysis. An IO-based hybrid analysis technique that requires the extraction of particular paths from the direct IO matrix has been developed. The potential for embodied energy paths to be used as the basis for a hybrid analysis of the Australian residential building sector is discussed. The results indicate that less than three-quarters of the total embodied energy of this sector is likely to be able to be validated, because of the complexity of the embodied energy paths.
Embodied energy (EE) analysis has become an important area of energy research, in attempting to trace the direct and indirect energy requirements of products and services throughout their supply chain. Typically, input-output (I-O) models have been used to calculate EE because they are considered to be comprehensive in their analysis. However, a major deficiency of using I-O models is that they have inherent errors and therefore cannot be reliably applied to individual cases. Thus, there is a need for the ability to disaggregate an I-O model into its most important 'energy paths', for the purpose of integrating case-specific data. This paper presents a new hybrid method for conducting EE analyses for individual buildings, which retains the completeness of the I-O model. This new method is demonstrated by application to an Australian residential building. Only 52% of the energy paths derived from the I-O model were substituted using case-specific data. This indicates that previous system boundaries for EE studies of individual residential buildings are less than optimal. It is envisaged that the proposed method will provide construction professionals with more accurate and reliable data for conducting life cycle energy analysis of buildings. Furthermore, by analysing the unmodified energy paths, further data collection can be prioritized effectively.
Environmental impact of building materials Technical Research Centre of Finland ͑VTT͒, Espoo, Finland. International Federation of Institutes for Advanced Study ͑IFIAS͒. ͑1974͒. ''Energy analysis workshop on methodology and conventionAn overview of greenhouse emissions in the car's life cycle
- T Hä
- ͑1994͒
- Y Parikh
- H C Watson
- W W S Charters
- ͑1995͒
Hä, T. ͑1994͒. ''Environmental impact of building materials.'' Technical Research Centre of Finland ͑VTT͒, Espoo, Finland. International Federation of Institutes for Advanced Study ͑IFIAS͒. ͑1974͒. ''Energy analysis workshop on methodology and convention.'' Workshop Rep. No. 6, Stockholm, Sweden. Parikh, Y., Watson, H. C., and Charters, W. W. S. ͑1995͒. ''An overview of greenhouse emissions in the car's life cycle.'' Proc., Int. Symp. on Energy, Environment and Economics, E. J. Colville, ed., Univ. of Melbourne, Melbourne, Australia, 607– 618.
Australian national ac-counts: Input-output tables Catalog No. 5209.0, Canberra, Australia. Australian Bureau of Statistics ͑ABS͒. ͑1996b͒. ''Australian national ac-counts: Input-output tables commodity details
- Australian Bureau
- ͑abs͒ Statistics
- ͑1996a͒
Australian Bureau of Statistics ͑ABS͒. ͑1996a͒. ''Australian national ac-counts: Input-output tables.'' Catalog No. 5209.0, Canberra, Australia. Australian Bureau of Statistics ͑ABS͒. ͑1996b͒. ''Australian national ac-counts: Input-output tables commodity details.'' Catalog No. 5215.0, Canberra, Australia. Ballinger, J., Prasad, D., Lawson, B., Samuels, R., and Lyons, P. ͑1995͒.
Life cycle costing: Whole-of-life cost analysis for heavy duty pavements.” Rep. prepared for Australian Asphalt Pavement Association Statewide Roads Technical Management Ltd
- K F Porter
- A Tinni
Porter, K. F., and Tinni, A. ͑1993͒. ''Life cycle costing: Whole-of-life cost analysis for heavy duty pavements.'' Rep. prepared for Australian Asphalt Pavement Association, Statewide Roads Technical Manage-ment Ltd.
The environmental impact of construction: A case study, Australia and New Zealand Architectural Science AssociationExtracting embodied energy paths from input-output tables: Towards an input-output-based hybrid energy analysis method
- G Treloar
- ͑1996͒ Australia
- G J Treloar
- ͑1997͒
Treloar, G. ͑1996͒. The environmental impact of construction: A case study, Australia and New Zealand Architectural Science Association, Sydney, Australia. Treloar, G. J. ͑1997͒. ''Extracting embodied energy paths from input-output tables: Towards an input-output-based hybrid energy analysis method.'' Econ. Sys. Res., 9͑4͒, 375–391.
A framework for implementing ISO 14000 in construction.'' Environ-mental Management and Health
- Z Y Zhang
- L Y Shen
- P E D Love
- G Treloar
- ͑2000͒
Zhang, Z. Y., Shen, L. Y., Love, P. E. D., and Treloar, G. ͑2000͒. ''A framework for implementing ISO 14000 in construction.'' Environ-mental Management and Health, 11͑2͒, 139–148.
An overview of greenhouse emissions in the car’s life cycle
- Y Parikh
- H C Watson
- W W S Charters
Parikh, Y., Watson, H. C., and Charters, W. W. S. 1995. ''An overview
of greenhouse emissions in the car's life cycle.'' Proc., Int. Symp. on
Energy, Environment and Economics, E. J. Colville, ed., Univ. of
Melbourne, Melbourne, Australia, 607-618.
Life cycle costing: Whole-of-life cost analysis for heavy duty pavements.'' Rep. prepared for Australian Asphalt Pavement Association
- K F Porter
- A Tinni
Porter, K. F., and Tinni, A. 1993. ''Life cycle costing: Whole-of-life cost
analysis for heavy duty pavements.'' Rep. prepared for Australian
Asphalt Pavement Association, Statewide Roads Technical Management Ltd.
Environmental impact of building materials
- T Häkkinen
Häkkinen, T. 1994. ''Environmental impact of building materials.''
Technical Research Centre of Finland VTT, Espoo, Finland.
International Federation of Institutes for Advanced Study IFIAS.
1974. ''Energy analysis workshop on methodology and convention.''
Workshop Rep. No. 6, Stockholm, Sweden.
Australian national accounts: Input-output tables commodity details
Australian Bureau of Statistics ABS. 1996b. ''Australian national accounts: Input-output tables commodity details.'' Catalog No. 5215.0,
Canberra, Australia.
“R & D of current environmental technologies in Australia
- J Ballinger
- D Prasad
- B Lawson
- R Samuels
- P Lyons
Ballinger, J., Prasad, D., Lawson, B., Samuels, R., and Lyons, P. 1995.
''R & D of current environmental technologies in Australia.'' Proc.,
Pan Pacific Symp. on Building and Urban Environmental Conditioning in Asia.
Technical Research Centre of Finland VTT, Espoo, Finland. International Federation of Institutes for Advanced Study IFIAS. 1974. ''Energy analysis workshop on methodology and convention
- T Häkkinen
Häkkinen, T. 1994. ''Environmental impact of building materials.''
Technical Research Centre of Finland VTT, Espoo, Finland.
International Federation of Institutes for Advanced Study IFIAS.
1974. ''Energy analysis workshop on methodology and convention.''
Workshop Rep. No. 6, Stockholm, Sweden.
Rep. prepared for Australian Asphalt Pavement Association, Statewide Roads Technical Management Ltd
- K F Porter
- A Tinni
Porter, K. F., and Tinni, A. 1993. ''Life cycle costing: Whole-of-life cost
analysis for heavy duty pavements.'' Rep. prepared for Australian
Asphalt Pavement Association, Statewide Roads Technical Management Ltd.
The environmental impact of construction: A case study Australia and New Zealand Architectural Science Association Sydney Australia
- G Treloar
A comprehensive embodied energy analysis framework
- G J Treloar