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Conceptual pre-estimation of road tunnel costs is a vital yet challenging process during feasibility studies due to the prevailing underground uncertainties and risks. Most existing cost estimation approaches are deterministic, probabilistic methods are limited to a single cost examination. This paper introduces a probabilistic model for pre-estimating road tunnels life-cycle costs. It aims to capture their inherent uncertainty holistically, thus enabling more reliable decision-making at a project's early stages. The proposed model is developed in three steps: multiple regression analysis, fitting distribution, and Monte-Carlo simulation. The first step unveils the correlations between independent and dependent variables, while the other two steps return the probabilistic descriptions of cost drivers and life-cycle costs. Civil engineering, electromechanical works costs, energy consumption, and operation & maintenance costs are determined as the model's output variables. A real-world database of 32 dual-bore road tunnels with a total length of 55 km is used to develop probability distributions within reasonable confidence intervals and a sensitivity analysis was performed utilizing tornado charts. The results can assist public authorities and managers in estimating the probability of a specific life-cycle cost and making appropriate decisions in accordance with their risk tolerance. [ABSTRACT FROM AUTHOR]

This study focuses on compressor station investments in Germany's natural gas infrastructure, offering insights applicable to machinery, energy, and maintenance cost-driven decisions. A life cycle cost (LCC) analysis can guide investment choices; however, uncertainties in input data and future developments pose risks. The LCC-based studies encounter questions impacting their results and optimal selections. These uncertainties may lead to misallocations, emphasizing the need for careful consideration of investment decisions to avoid potential consequences and efficiently allocate limited funds. Various measures are available to mitigate the uncertainties and risks in LCC analyses. Recognized measures are deterministic and probabilistic. Seven case studies on investments in the natural gas infrastructure in Germany were analyzed in this context. In addition to the executed case studies, a case study from a scientific journal (published in 2001) was included in the analysis. The case studies were conducted by transmission system operators from 2005-2015, and a retrospective view made it possible to recognize whether the best options (due to the LCC analysis) were identified. Simulations were conducted with generated models using real historical input data such as energy costs. The re-calculation of the net present value or better discounted cumulated expenditure with real input data shows that the LCC analysis results are significantly dependent on the reliability of the input data and the prediction of their development. Therefore, validating the results using appropriate measures is mandatory. This study illustrates how sensitivity analysis can be used as a deterministic method to evaluate the LCC analysis results. A company's success is increasingly determined by its sustainability. A pure LCC analysis is insufficient, so social, ecological, and economic sustainability assessments must be conducted. This study demonstrates the effectiveness of the weighted scoring method for sustainability assessments. Although this study relates to LCC in Germany's natural gas infrastructure, the suggested process can be adopted for other investment projects comprising capital and operational expenditures. [ABSTRACT FROM AUTHOR]

This study was carried out in a building located in Antalya in order to determine the optimum combinations of different levels of improvement and PV panel use in existing buildings in terms of energy saving and LCC. Within the framework of TS 825 Thermal Insulation Rules in Buildings, which is the national standard in Turkey, three different levels of insulation in walls, roofs, floors and windows and three different numbers of PV panels for energy production were determined. 18 different alternatives obtained using the orthogonal array for five factors with three levels analyzed have been made. In terms of energy savings, the scenario with the highest levels of insulation for walls, roofs, floors and windows and the use of 12 PV panels is the optimum combination that produces all of its energy needs and switches to surplus energy with +KW after consumption. In terms of LCC, the alternative with 12 PV panels, where wall, floor and windows are the highest and the roof is insulated at level 2, is the best combination. PV panel integration was found to be the most effective parameter in terms of energy savings and LCC. [ABSTRACT FROM AUTHOR]

The automotive market is currently shifting away from traditional vehicles reliant on internal combustion engines, favoring battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). The widespread acceptance of these vehicles, especially without government subsidies, hinges on market dynamics, particularly customers opting for vehicles with the lowest overall cost of ownership. This paper aims to model the total cost of ownership for various powertrains, encompassing conventional vehicles, HEVs, PHEVs, and BEVs, focusing on both sedans and sports utility vehicles. The modeling uses vehicle dynamics to approximate the fuel and electricity consumption rates for each powertrain. Following this, the analysis estimates the purchase cost and the lifetime operational cost for each vehicle type, factoring in average daily mileage. As drivers consider vehicle replacements, their choice tends to lean towards the most economical option, especially when performance metrics (e.g., range, acceleration, and payload) are comparable across the choices. The analysis seeks to determine the percentage of drivers likely to choose each vehicle type based on their specific driving habits. Advances in battery technology will reduce the battery weight and cost; further, the cost of electricity will decrease as more renewable energy sources will be integrated into the grid. In turn, the total cost of ownership will decrease for the electrified vehicles. By following battery trends, this study is able to model the makeup of the automotive market over time as it transitions from fossil-fuel based vehicles to fully electric vehicles. The model finds until the cost of batteries and electricity is significantly reduced, the composition of the vehicle market is a mixture of all vehicle types. [ABSTRACT FROM AUTHOR]

This study focuses on compressor station investments in Germany’s natural gas infrastructure, offering insights applicable to machinery, energy, and maintenance cost-driven decisions. A life cycle cost (LCC) analysis can guide investment choices; however, uncertainties in input data and future developments pose risks. The LCC-based studies encounter questions impacting their results and optimal selections. These uncertainties may lead to misallocations, emphasizing the need for careful consideration of investment decisions to avoid potential consequences and efficiently allocate limited funds. Various measures are available to mitigate the uncertainties and risks in LCC analyses. Recognized measures are deterministic and probabilistic. Seven case studies on investments in the natural gas infrastructure in Germany were analyzed in this context. In addition to the executed case studies, a case study from a scientific journal (published in 2001) was included in the analysis. The case studies were conducted by transmission system operators from 2005–2015, and a retrospective view made it possible to recognize whether the best options (due to the LCC analysis) were identified. Simulations were conducted with generated models using real historical input data such as energy costs. The re-calculation of the net present value or better discounted cumulated expenditure with real input data shows that the LCC analysis results are significantly dependent on the reliability of the input data and the prediction of their development. Therefore, validating the results using appropriate measures is mandatory. This study illustrates how sensitivity analysis can be used as a deterministic method to evaluate the LCC analysis results. A company’s success is increasingly determined by its sustainability. A pure LCC analysis is insufficient, so social, ecological, and economic sustainability assessments must be conducted. This study demonstrates the effectiveness of the weighted scoring method for sustainability assessments. Although this study relates to LCC in Germany’s natural gas infrastructure, the suggested process can be adopted for other investment projects comprising capital and operational expenditures.

The automotive market is currently shifting away from traditional vehicles reliant on internal combustion engines, favoring battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). The widespread acceptance of these vehicles, especially without government subsidies, hinges on market dynamics, particularly customers opting for vehicles with the lowest overall cost of ownership. This paper aims to model the total cost of ownership for various powertrains, encompassing conventional vehicles, HEVs, PHEVs, and BEVs, focusing on both sedans and sports utility vehicles. The modeling uses vehicle dynamics to approximate the fuel and electricity consumption rates for each powertrain. Following this, the analysis estimates the purchase cost and the lifetime operational cost for each vehicle type, factoring in average daily mileage. As drivers consider vehicle replacements, their choice tends to lean towards the most economical option, especially when performance metrics (e.g., range, acceleration, and payload) are comparable across the choices. The analysis seeks to determine the percentage of drivers likely to choose each vehicle type based on their specific driving habits. Advances in battery technology will reduce the battery weight and cost; further, the cost of electricity will decrease as more renewable energy sources will be integrated into the grid. In turn, the total cost of ownership will decrease for the electrified vehicles. By following battery trends, this study is able to model the makeup of the automotive market over time as it transitions from fossil-fuel based vehicles to fully electric vehicles. The model finds until the cost of batteries and electricity is significantly reduced, the composition of the vehicle market is a mixture of all vehicle types.

This study presents a comprehensive analysis of an Alkaline Water Electrolysis System (AWES) for hydrogen production, focusing on thermal balance, operating conditions, efficiency, and lifecycle cost. A thermal balance model was developed and further refined using machine learning techniques based on experimental data, to accurately calculate electrolysis power, cooling requirements, and temperature maintenance, enabling cost-effective operation. This study provides insights for optimizing AWES performance and economic feasibility in hydrogen production. Selecting appropriate operating conditions considering current density, inlet temperature, and electricity price is crucial. Implementing these optimizations improves energy efficiency, reduces lifecycle hydrogen production costs, and enables integration with renewable energy systems. • An overall understanding of the alkaline electrolyzer operating conditions and performance is provided. • A universal modeling method based on thermal-balance model for operation optimization is proposed. • Machine learning approach is applied to calibrate model accuracy. • Mapping of hydrogen production efficiency and cost effectiveness is produced for full operation range. [ABSTRACT FROM AUTHOR]

Geopolymer is relatively newer binder developed as an alternative to conventional cementitious binders. It lowers CO2 emissions, consumes less energy, and effectively utilises industrial wastes. The alkali activator solution, used in traditional two-part geopolymer to initiate the polymerisation reactions, is highly viscous and corrosive, which limits the effective utilisation of geopolymer concrete in construction. Consequently, a single-component "just add water" geopolymer system was developed to address the issues of cast in situ applications of two-part geopolymer concrete. This paper discusses the diverse examinations of the various source materials and alkali activators employed over the years in synthesising single-component geopolymer (SCG) along with their detailed chemical analysis. In addition to the different constituent types, the effect of various curing conditions, e.g., ambient or elevated temperatures, admixtures were also presented on the properties (physical, mechanical, and durability) of SCG-based paste/mortar/concrete. Such detailed analysis of the chemical composition and engineering properties of various SCG mixes would help the researcher and material designer to choose a suitable mix proportion based on the targeted performance. Further, based on an in-depth analysis of the various bindings phases (e.g., CSH and CASH) formed in SCG, the schematic representation of the reaction mechanism was highlighted. This paper also highlighted the life-cycle cost analysis (LCCA) and current challenges in the production of SCG. Therefore, the present review article would serve as a source of information for the scientific community to understand the current research trend in the development of SCG binder, its design and consequent prediction of various engineering properties made with different constituent materials and would serve as a source of information for further research and development which is one step towards the goals of net zero emissions by 2050 through a sustainable approach. [ABSTRACT FROM AUTHOR]

This paper presents the development of a tool that aims to help stakeholders make informed decisions to invest in renewable energy and understand the impact of different tariffs on the economic viability of renewable energy investments. This includes evaluating the costs and benefits, and assessing the impacts of different tariff structures on the economic feasibility of those options. Furthermore, the tool can help in identifying the potential risks and challenges associated with renewable energy integration projects, such as market and network charges fluctuations. Therefore, this tool provides various evaluations to inform users about their energy consumption in relation to sport market energy prices, network tariffs, and retailer charges. It enables the assessment of a site’s economic operation over specific timeframes, calculates potential energy savings from on-site renewable sources, and determines economic indicators based on life-cycle cost analysis. The tool has been designed and validated with data from the Australian energy market, focusing on investment decisions for renewable energy projects in Victoria state. It adheres to the Australian Energy Market Regulations and incorporates feed-in tariff rates particular to the Victorian energy market and its regulatory framework.

Roads, bridges, sewer systems, and other infrastructure failures often result from climate-related incidences along with extensive socioeconomic impacts including human life losses. Infrastructures with frequent experiences are usually replaced, altered, or adopt different Low-Impact Development, Best Management Practice (LID-BMP) approaches. Adapting and recovering from the damages cost a substantial budget. This study reviewed Multicriteria Decision Analysis (MCDA) i.e., risk analysis, hydroclimatic analysis, and Life Cycle Cost-Benefits Analysis (LCC-BA) in the Climate-Resilient Infrastructure Development (CRID). It was carried out following the protocols and guidelines for systematic literature review. Throughout the review, 1D is acclaimed as the best and most suitable to identify critical flooding zones and nodes within the drainage network. The study showed that integrated GIS and 1D hydrodynamic modelling are reliable in waterlogging characterisation and locating suitable floodwater regulating areas, while 2D analysis was found ideal for appropriate damages assessment over different inundation depths, duration, return periods and different climate scenarios. Indeed, about 62.5% of the studies have analysed the LID-BMPs whereby 23.2% integrated hydrologic-hydrodynamic and LCC-BA, and identified optimum performances at different levels. The study showed that, the cost of climatic adaption in infrastructure development results in the benefits optimisation and the effects-attributed cost minimisation. Besides, several studies acclaim the rising of weather-related extremes due to a gradual climate variation. Henceforth, there is a need for adaptation, most importantly, incorporating the changes in infrastructure development, and the necessity of integrating MCDA in CRID. Further, machine learning and deep learning approaches are recommended to overcome challenges and limitations associated with the current multi-dimensional numerical models and big data era demanding huge time and computational power.

One of the most effective ways to save energy for cooling and heating applications is thermal insulation. Because of this, determining the ideal insulation thickness is a popular topic for publications. The purpose of this study is to determine the appropriate insulation thickness needed for a submarine's external construction while it is cruising in various locations. Since seawater makes up a submarine's external environment, situations involving five distinct seawater temperatures from around the globe have been studied. There are five of them: the Mediterranean, Marmara, Aegean, Black Sea, and Sakhalin, which is in the North Pacific Ocean and has the coldest seawater on earth. By using the idea of degree-days, the annual cooling and heating needs of submarines in various regions have been computed. Based on life cycle cost analysis, optimization has been accomplished. In the beginning, the results of a study published in the literature supported the calculation methods utilized. The use of insulation materials such as rock wool, glass wool, polyurethane, expanded polystyrene, fiberglass, and foam glass, as well as fuel oil to run the generator, has been taken into account in a number of calculations, including the best insulation thickness, annual savings value, annual energy cost, and payback period. The findings indicate that depending on seawater temperatures and insulation materials, the ideal insulation thicknesses range between 2 and 12 cm, energy savings between 8.5% and 90%, and payback periods between 1.1 and 10 years. [ABSTRACT FROM AUTHOR]

An accelerated pavement testing (APT) facility is proposed for the dry–freeze climatic region of the United States to test pavement materials under a full-scale test road parallel to an existing corridor of Interstate (I-80) in Wyoming. Economic assessment of APT program is necessary to address funding issues, increase accountability, and encourage partnership. However, the effect of uncertainty associated with the economic evaluation of APT programs is a shortcoming in making investment decisions because it can generate subjective decision-making. Several authors acknowledged the difficulty in assessing the benefits of their APT programs due to the uncertainty and subjectivity. However, these authors used deterministic and probabilistic life-cycle cost analysis (LCCA) and sensitivity analysis to address the uncertainty. Although the probabilistic methods have proven effective to overcome this problem, the significant amount of data needed is a drawback and affects its usage. The authors have used these approaches to determine the benefits of APT programs after years of operation and none at the planning stage. When it comes to assessing the economic feasibility at the planning stage, input variables are more of vagueness and subjectivity rather than randomness. This study integrates both deterministic and fuzzy approaches with sensitivity analysis to provide a comprehensive framework to determine the economic benefits of APT facilities at the feasibility study using the proposed test track in Wyoming as a case study. The expected benefit–cost (B/C) ratio of participating states and the overall B/C ratio of the proposed facility is presented. The results reveal that the proposed APT program is economically advantageous, and the fuzzy logic LCCA is a promising alternative approach to perform B/C ratio as an input for planning future APT programs. Partnerships are encouraged to make the APT program more cost-effective and sustainable. Future economic assessment of APT investments with soft computing techniques is recommended. [ABSTRACT FROM AUTHOR]

Increasing envelope facet albedos considerably reduces solar heat gain, thus yielding building cooling energy savings. Few studies have explored the potential benefits of utilizing cool coatings on building envelopes (“cool-coated buildings”) based on life-cycle cost analysis. A holistic approach integrating the field testing, building energy simulation, and a 20-year life-cycle-based optimization was developed to explore cool-coated building performance and the maximum net savings of optimal building envelope retrofit and design. Experimental results showed that applying cool coatings to a west wall of an office building in Chongqing, China reduced its exterior surface temperature by up to 9.3 °C in summer. Simulation results showed that in Chongqing, making the roof and walls cool could reduce annual HVAC electricity use by up to 11.9% in old buildings (with poorly insulated envelopes) and up to 5.9% in new buildings. Retrofitting old buildings with a cool roof provided the net savings per modified area with present values up to 42.8 CNY/m2; retrofitting a new building with a cool roof or cool walls was not cost-effective. Optimizing both envelope insulation and envelope albedo can achieve 5.6 times the net savings of optimizing the insulation only, and 1.6 times that of optimizing albedo only.

Summary: Tall buildings located in Hong Kong can suffer great damage caused by typhoon hazards throughout their lifetimes. In addition, the effect of wind hazards may be exacerbated due to increases in the typhoon intensity and frequency caused by the climate change effect. Therefore, developing a framework to evaluate and quantify the damage caused by wind hazards on tall buildings from the economic perspective is critical for engineers and building owners in designing a cost‐effective tall building. In this study, an economic damage indicator, life‐cycle cost, is measured by using a probabilistic method called life‐cycle cost analysis (LCCA). Moreover, the building sector is one of the biggest contributors to greenhouse gas (GHG) emissions, and the environmental impact that may be generated in intervention activities after wind‐induced damage occurs is analyzed. An environmental impact indicator, embodied carbon emission, is quantified by employing another probabilistic method called life‐cycle assessment (LCA). Therefore, an integrated methodology combining the LCCA and LCA is proposed to evaluate potential damage costs and environmental impact caused by typhoon hazards on tall buildings. [ABSTRACT FROM AUTHOR]

The edge beams of reinforced concrete bridges with de-icing salts sprayed experience extensive corrosion damage. The average service life of edge beams needing replacement in Sweden has been reported as only 45 years, causing great economic loss to both owners and users. Hence, finding a durable solution for edge beams would benefit society. Hybrid reinforced concrete structures, produced by adding a low-to-moderate fibre content into traditional reinforced concrete, can effectively limit the service crack width and improve resistance to chloride-induced corrosion damage. In this paper, different alternatives of hybrid and traditional reinforced edge beams were designed for a case study. The service life of the alternatives was compared by conducting chloride diffusion calculations and by applying a corrosion-induced cracking model. The economic and environmental (indicated by greenhouse gas emissions) benefits of using hybrid reinforced edge beams were assessed by life-cycle cost analysis and life-cycle assessment. The results showed that the service life of edge beams made of hybrid reinforced concrete can be prolonged by over 58%, thereby enabling a significant reduction in the total life-cycle costs and annual total greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Viscoelastic (VE) dampers are powerful tools for mitigating structural response when exposed to an earthquake. The fractional models for these dampers are adequately capable of taking the effects of ambient temperature and excitation frequencies into account. In this paper, the effect of these dampers on reducing the life-cycle cost of steel structures and the exceedance probability of different damage states is evaluated during the lifetime of the structures. Modal pushover analysis has been employed for nonlinear dynamic analysis of the steel frames with viscoelastic dampers. The effect of the random parameters, such as ambient temperature, excitation frequency, and accelerogram type, were also considered. The results from the analysis of six presented scenarios demonstrate a significant improvement in structural performance, especially in reducing the maximum inter-story drifts and ductility demands. Incorporating VE dampers into different design scenarios has decreased the expected damage cost and total life-cycle cost of the structure by at least 58% and 31%, respectively. Also, it was observed that due to the nonlinearity of the equations and uncertainties associated with seismic loading and ambient temperature, the best design scenario is not easily predictable. [ABSTRACT FROM AUTHOR]

Many state transportation agencies are faced with making pavement rehabilitation decisions for roadways annually. Their design choices affect the future performance and maintenance cost of those pavements. This study determines if it is cost-effective to perform a field investigation (e.g., FWD, coring) for non-interstate routes to identify pavement structural and functional characteristics at the design stage and whether this information can aid in determining the most appropriate design for rehabilitation. To this end, field investigations are performed on 16 actual roadways (non-interstate routes) in the state of South Carolina prior to their rehabilitation, and an analysis was performed to compare the life-cycle cost between rehabilitation designs with and without field investigations. The results indicate that (1) the rehabilitation design with field investigation tends to produce a pavement that has the necessary depth and made up of higher strength materials that bring the pavement’s SN closer to the required value, (2) the rehabilitation design with field investigation defers the maintenance cycles, and (3) performing field investigation is cost-effective, particularly for those pavements that do not need maintenance treatments until their present serviceability index falls to a 2.

Although retrofitting existing buildings is an important step toward sustainability, most research have concentrated on the sustainability of new structures. Existing buildings retrofit is being questioned, particularly in terms of selecting the optimal solution. Additionally, thermal comfort is crucial for patient satisfaction in healthcare facilities, but enhancing this factor increases energy use. However, envelope retrofitting of healthcare facilities buildings stock provides a high potential for energy savings. Consequently, this study aims to develop envelope retrofitting guidelines for uninsulated healthcare buildings in Jordan and to propose locally available retrofit measures. The difference in the building performance before and after retrofit is used to assess potential energy savings. Next, this outcome is used in a life cycle assessment (LCA) to examine the economic and environmental feasibility of the proposed retrofit measures using life cycle cost and life cycle CO2. This procedure combines the best economic and environmental measures available to create a comprehensive retrofit strategy. Thus, this study adopts a mixed-method design combining quantitative and qualitative methods, including physical analysis, national archives, and questionnaires. The results show that all proposed measures are economically and environmentally feasible, and the combination of two or more measures could produce up to 33% energy savings. Finally, the holistic approach strategy is investigated with various healthcare facilities’ life cycle.

[Display omitted] • A novel MOF encapsulated by Fe(III)-substituted H 3 PW 12 O 40 was developed. • Sustainable microwave-assisted biodiesel production in a short duration of 40 min. • FPW-HK catalyst significantly reduced energy consumption and time with E a = 27.24 kJ/mol. • Possible mechanism of biodiesel production on the catalyst surface was proposed. • Life-cycle cost analysis estimated the cost of 1 kg of biodiesel to be $0.6. In the present research, an attempt has been made to design a highly efficient Metal-Organic Framework encapsulated by Fe (III)-substituted keggin H 3 PW 12 O 40 nanocomposite for the production of biodiesel via microwave-assisted esterification reaction within a very short duration of 40 min. This phenomenon can be attributed to the enhanced mass transfer between the surface of the catalyst and the reactants, leading to a reduction in reaction time and energy consumption. Notably, the FPW-HK catalyst significantly lowers the activation energy to 27.24 kJ/mol, achieving an outstanding biodiesel yield of 99.14 ± 0.4 % at optimum reaction conditions, with a pseudo-first order rate constant of 0.08954 min−1. This signifies that the reaction catalyzed by the fabricated FPW-HK catalyst is highly energy efficient. Moreover, from the perspective of time and cost-effectiveness, the fabricated catalyst has the potential to reduce the overall cost of the biodiesel production, as validated by life-cycle cost analysis (LCCA). 1HNMR, 13CNMR, and GC–MS analysis were performed to quantify the composition of the produced biodiesel. Onward, the investigation of the influence of various process factors such as OA, methanol molar ratio, catalyst loading, reaction time, and temperature was performed to optimize the esterification reaction. Furthermore, a possible reaction mechanism over the surface of the synthesized FPW-HK nanocatalyst was suggested to discuss the production of biodiesel. The catalyst displayed good reusability up to six cycles besides demonstrating potential for industrial applications. The LCCA estimated the price of 1 kg of biodiesel to be merely $0.593, suitable for commercialization. Moreover, it exhibits potential for the esterification of low-cost feedstocks with high content of free fatty acids (FFA), thus displaying immense utility for industrial applications. The results suggest that the combination of MOF-supported keggin heteropolyacids and microwave irradiation can be a promising alternative to biodiesel production with reduced time and energy consumption, besides holding a significant promise for large-scale green biodiesel production for commercialization. [ABSTRACT FROM AUTHOR]

Green envelopes show significant potential in energy conservation and thermal comfort enhancement in office buildings. This study presents a comprehensive method integrating field tests, building energy simulations, and optimization in office buildings in Chongqing, China. A 20-year life-cycle cost analysis was conducted to evaluate the benefits of green roofs (using sedum lineare container-type planting modules) and green façades (featuring vertical kudzu greenery systems). The results indicate that green roofs could reduce peak temperatures by up to 34.3 °C, leading to daily energy savings of 12.5 % during summer. Green façades decreased the wall exterior surface temperatures by up to 3.4 °C and 5.1 °C on the test cold and hot days, respectively. The maximum annual building electricity savings per green-modified area was 22.8 kWh/m2 for the poorly-insulated building and 5.4 kWh/m2 for the well-insulated one. This study highlights the cost-effectiveness of green envelopes in improving building efficiency. The optimal retrofit measure for the poorly-insulated building was the combination of green roofs and daylighting dimming control systems, yielding a 20-year life-cycle net savings per floor area of 81.5 CNY/m2. For the well-insulated building, the daylighting dimming control system alone provided optimal net savings per floor area of 26.4 CNY/m2. • A holistic method was proposed to integrate and optimize green roofs and green façades. • Green envelopes yielded notable thermal and energy-saving benefits in office buildings. • Green roofs reduced peak temperatures by 34.3 °C, saving 12.5 % energy daily in summer. • Green façades led to a mean decrease of 2.3 °C in the exterior temperature of curtain wall surfaces. • Green roofs and daylighting control had the highest economic benefits in poorly-insulated buildings. [ABSTRACT FROM AUTHOR]

This paper investigates the environmental and economic impacts of hydrogen-powered ferries in inland passenger and car transportation using Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA). Three types of electrolysers and two types of fuel cells, focusing on their manufacturing locations, are compared with two Marine Diesel Oils (MDOs) with various sulphur percentages. In addition, this study utilises the Analytical Hierarchy Process (AHP) to weigh and rank the environmental impacts of all power options based on expert opinions. As a result of the combination of LCA and AHP analysis, the most environmentally friendly power option is found to be the Solid Oxide Electrolyser-Solid Oxide Fuel Cell system for the case study, while the worst option is the Proton Exchange Membrane Electrolyser- Proton Exchange Membrane Fuel Cell system. Moreover, MDOs are the most cost-effective power options in all carbon-tax scenarios. • 99.5 % of the life-cycle GWP of hydrogen power options arises from electricity usage. • The most environmentally friendly power option is found to be the SOEC-SOFC system. • In all carbon-tax scenarios, MDOs are the most cost-effective power options. • A 1% increase in electricity price leads 0.57–0.86% escalation in LCOH. [ABSTRACT FROM AUTHOR]

Probabilistic Damage Control Application (PDCA) has been developed to apply the performance-based earthquake engineering (PBEE) to the seismic design of highway bridge structures. The main component of the PDCA is the total risk that enables designers to conduct a life-cycle cost analysis and to answer the owner's cost-related questions such as how to optimize the design by balancing two primary decision-making parameters: performance and cost. This paper introduces an enhanced total risk model adopting the backbone formula used for calculating the annual rate of exceeding intensity measure (IM) level in Probabilistic Seismic Hazard Analysis (PSHA). The life-cycle cost analysis is a function of initial construction cost, repair costs, and economic loss. The inclusion of expected repair costs and economic consideration results in a comprehensive life-cycle cost analysis that makes the PDCA methodology unique. A detailed case study using a multispan bridge is presented as an example to show how to apply the PDCA framework into the bridge design practice with an emphasis on the life-cycle cost analysis that is computed using the total risks. Bridge column is the main seismic critical member in the bridge system that has nonlinear performance under seismic events. The total risk model and loss analysis of the PDCA addressed in this paper is based on the seismic performance of the bridge columns only. Other components such as abutment and in-span hinge seat widths that will have some contribution to the total risk may be considered in the future. [ABSTRACT FROM AUTHOR]

This paper presents the development and utilisation of a heat regeneration approach to enhancing the performance and reducing the life-cycle cost of supercooled water ice slurry generation systems. Two supercooled water systems with direct and indirect ice slurry generation were enhanced by the heat regeneration approach to avoid excessive cold loss and increase the supercooling degree, thereby improving system efficiency while reducing operational costs. Their respective performance and life-cycle costs were experimentally evaluated and compared to the ones without heat regeneration enhancement under different working conditions, as well as to a conventional scraped surface ice slurry generator used as a benchmark. It was found from the comparative investigation that the heat regeneration approach can effectively reduce the water temperature at the inlet of the supercooler, allowing a significant amount of cold loss to be saved for ice slurry generation. The effective utilisation rate of cold can be effectively improved by over 15% when using the heat regeneration approach, and the unit ice mass power consumption can be reduced by 12–20%. Due to the attractive energy-saving potential, the operational cost-effectiveness of the enhanced systems contributed to cut-down of life-cycle cost. It was found that the life-cycle costs of the enhanced direct and indirect ice slurry generation systems were 62.0% and 74.7% lower than that of the conventional scraped surface ice slurry generator, respectively. [ABSTRACT FROM AUTHOR]

Airports play a critical role in transporting goods and passengers and supporting the growth of the world economy. Airports spend huge sums annually to maintain and improve pavement functions by expanding the runways, taxiways, and aprons, and perform routine maintenance and rehabilitation of the existing pavements. Besides the traditional direct costs, a comprehensive airport pavement management system should also consider indirect costs such as fuel, crew, passenger delay, aircraft maintenance, and loss of airport revenue when conducting a life-cycle cost analysis (LCCA). Engineers, managers, and stakeholders can make better decisions on the appropriate pavement maintenance and rehabilitation strategies by performing economic analyses of the direct and indirect costs. This study performed probabilistic and deterministic LCCA to contrast the effect of direct costs vis-a-vis indirect costs in airport pavement management. A case study found that indirect costs could contribute up to 20% of the total costs when using Portland cement concrete (PCC), hot mixed asphalt (HMA), and crack seat overlay (CSOL). Previous research did not give much attention to maintenance since the researchers believed that routine maintenance makes up only an insignificant percentage of the LCCA. However, routine maintenance of HMA and CSOL makes up 10.2% and 14.2% of the total cost. The rehabilitation cost of PCC makes up 16.3% of the total cost, and the rehabilitation cost for HMA and CSOL makes up 25.4% and 35.2% of the total cost. [ABSTRACT FROM AUTHOR]

Life-cycle cost analysis is an approach that has gained popularity for assisting the design of civil infrastructures. The life-cycle cost analysis approach can be leveraged for structures equipped with structural health monitoring systems in order to quantify the benefits of the technology and de facto support its long-term implementation. However, for new structures, the long-term assessment of the expected value of the total investment cost, in terms of the current worth at the design time, is still the focus of ongoing research due to unknowns and uncertainties on the impact of the structural health monitoring system on long-term structural performance. This article proposes a new combined model of life-cycle cost formulation and simulation methodology for the long-term financial assessment of transportation bridges equipped with seismic structural health monitoring systems, in order to evaluate the total costs and benefits offered by such monitoring systems for post-seismic assessments. The formulation characterizes the time evolution of bridge management cost terms, highlighting the most sensitive parameters. The simulation methodology allows to quantitatively weigh each maintenance action on the total cost based on when the action is performed. The model is used to compare structures managed by the traditional approach of post-earthquake inspection versus those managed by a condition-based approach enabled by structural health monitoring systems. The originality of the model empowers the comparison by payback time, defined as the break-even point between costs and benefits of a structural health monitoring system, as well as by economic gain, defined as the difference between the total costs of an unmonitored versus a monitored structure through the end of service life. The proposed model is demonstrated through parametric analyses on a case study consisting of a continuous steel-concrete composite bridge, where the structural health monitoring system is used to monitor the elastic limit state condition of bending forces in piers during the earthquake. [ABSTRACT FROM AUTHOR]

Owners and designers are increasingly dealing with infrastructure maintenance to ensure adequate level of performance and functioning required by current standards. Corrosion of reinforcement is one of the major factors that reduces the durability of concrete structures. Fiber reinforced polymers (FRP) have emerged as an effective non-corrosive alternative to traditional steel reinforcement (CS), especially for bridges located in chloride-laden environments. This paper aims to undertake probabilistic and deterministic Life-Cycle Costs (LCC) analyses for: a) an entirely FRP-reinforced concrete bridge; and, b) a conventional reinforced concrete (RC)/prestressed concrete (PC) bridge; assumed to be located in different corrosion intensity locations of Florida. The deterministic LCC analysis is investigated as a function of varying chloride concentrations for different locations in Florida. A probabilistic analysis is then performed to account for uncertainties in the deterministic model based on a selected coefficient of variation value. For each maintenance intervention, the probabilistic model yields a range of potential effects produced on the LCC by the same cause, ultimately producing more realistic results. The probabilistic model is validated through the input of maintenance and repair cost data from actual in-service bridges. In the probabilistic model, the repair cost is evaluated as a smooth curve, and the results are sensitive to the selection of the coefficient of variation adopted. The probabilistic model allows for better estimation and prediction of the range of long-term LCC behavior of both bridge alternatives. The CS-RC/PC alternative is found to be a high-risk design alternative with higher range (cost spread) and increased LCC. Data available to validate the probabilistic model show a promising match and revealed that the CS-RC/PC alternatives may become costlier earlier in time with a higher degree of probability.

Tall buildings are especially prone to damage caused by winds and earthquakes. In practice, only a single hazard is assumed to dominate the design and is adopted for structural verifications. This is also the case when supplemental damping devices such as tuned mass dampers (TMDs) are adopted. Nevertheless, previous research has shown that from a life-cycle cost (LCC) perspective the dominant hazard concept is misleading, and a multi-hazard approach is necessary. This article proposes a methodology for multi-objective optimization-based design of multiple TMDs (MTMDs) attached to tall buildings subjected to both winds and earthquakes. The LCC related to damage on non-structural components is taken as one of the objective functions to join consistently these hazards. The MTMDs initial cost is selected as the second objective function. The results of these multi-objective optimization problems are Pareto fronts of optimized solutions that may be of interest to stakeholders, including non-technical decision makers. A genetic algorithm is adopted as solution strategy. A realistic case study is presented, and the optimization results are compared with classic literature solutions. [ABSTRACT FROM AUTHOR]

Global warming is affecting the Earth's surface temperature and consequently the intensity of near‐surface airstreams and wind power potential in many regions. Conversely, global wind power installed capacity is continuously growing during the last years. The economic viability and sustainability of centralized wind projects relies heavily on wind resources, efficient technologies, and an attractive and dynamic Feed‐in‐Tariff (FIT). Therefore, this study assesses the potential effect of global warming on the life‐cycle techno‐economic viability of future wind power projects in Central Asia, specifically in Kazakhstan. Hence, the Ereymentau Wind Power Plant (WPP) in the Northern region of Kazakhstan was selected as case study. Historic data showed that monthly averaged wind speed and ambient pressure can be treated as statistically stationary, and only the air density drop due to temperature increase of 0.2°C per decade is assumed in the present study. Our results predict a reduction in Net Present Value, Benefit–Cost Ratio, and Internal Rate of Return of 29 million KZT, of 0.0015, and 0.03%, respectively, in the lifetime of Ereymentau WPP. Moreover, an Equity payback increase of 0.4 years and a drop of 987 tCO2e in GHG emission reductions are projected. Consequently, our results indicate that global warming, despite of being a global problem of significance, would have a negligible impact in ongoing plans to develop the wind potential in Northern regions of Eurasian countries sharing similar conditions to those present in Ereymentau‐Kazakhstan. [ABSTRACT FROM AUTHOR]

• A novel self-sustainable hybrid biogas plant for round year gas production. • Energy payback time, production factor, Life cycle conversion efficiency calculated. • N-PVT-FPC collector active heated biogas plant has been analyzed. • Annual thermal energy and exergy are 19.6 MWh and 1.9 MWh respectively. • Carbon credit earned was 95,658.29 $. Over time, hybrid energy systems have shown their effectiveness in meeting energy demands, achieving higher energy production, consistent power supply, saving energy costs, environmental benefits, and proving a sustainable solution to the growing energy demands. Worldwide researchers are looking for a hybrid, self-sustained energy system consisting of biogas and solar energy for round year high biogas production. However, an attempt has been made to evaluate the energy matrix like Energy payback time (EPBT), Energy production factor (EPF) and Life cycle conversion efficiency (LCCE) for a hybrid N-semi-transparent photovoltaic thermal and flat plate collector N-sPVT-FPC integrated biogas plant. Annual overall thermal energy and exergy are found to be 38.14 MWh and 20.41 MWh respectively. The EPBT was 2.74 years, and the energy production factor was found to be 0.3647 on an energy basis. EPF and LCCE were increasing with increasing lifetime of the system. The carbon credit during the entire lifetime was $ 1,59,602.6 by the proposed setup. The findings of this study underscore the viability and sustainability of the hybrid N-sPVT-FPC integrated biogas plant as a solution to meet energy demands. [ABSTRACT FROM AUTHOR]

Global efforts towards de-carbonization have opened the pathway for a test environment of electrical energy storage (EES) topology. In this work, the feasibility of 17 EES facilities applied to 24 individual applications of flexible power networks has been investigated in terms of levelized cost of storage (LCOS) in $/kW. Electricity storage facilities were modelled and evaluated via a life-cycle cost analysis, based on the most realistic EES characteristics and practical applications’ requirements. The results showed that pumped-hydro constitutes the least-cost and most reliable system for large-scale/long-duration applications. Zn-air and vanadium redox (VRB) offer great potential in demand-shifting and reactive support but, due to their wide LCOS range, considerable risk is added in such an investment. Electrochemical double-layer capacitor (EDLC) holds almost the exclusivity in fast-response/frequently-cycled applications, while for medium-term/medium-scale applications and where the large footprint is a prohibitive factor, valve-regulated Pb-acid (VRLA) and hydrogen fuel cells (H2-FC) are more favourable options. However, efficient tools still lack the ability of quantifying all benefits derived from electricity storage, maintaining stakeholders’ concerns for investment. It is apparent that, further research and development implies the decrease of the uncertainty governing the majority of EES technologies, increasing EES implementations and vice versa.

In this work, the impact of intermittent renewable energy sources on total production cost is evaluated, using annual data regarding the isolated power system of the island of Cyprus. Once electrical energy storage (EES) is identified as an approach enhancing flexibility and reliability, the selected EES facilities are modelled and evaluated via a life-cycle cost analysis, based on the most realistic characteristics and cost metrics found in the literature. The results derived from the uncertainty analysis performed, show that vanadium-redox flow battery provides the highest net present value (NPV). However, sodium-sulfur battery system offers the most secure investment in terms of uncertainty range and mean value, followed by lead-acid battery system. Lithium-ion battery system exhibits expensive capital cost which still governs its overall cost performance achieving a negative mean NPV far below zero.

The main structural elements of Reinforced Concrete (RC) bridges deteriorate with time under uncertain hazards such as scouring and corrosive conditions. In this paper, a multi-hazard framework is proposed to assess the performance of bridges subjected to the main effective uncertain natural hazards during their lifetime. In this assessment, the uncertainties associated with the combined effects of multiple hazards including pier scour, earthquake, carbonation, and corrosion are considered. Therefore, for each, hazard their severity relationships have been extracted over time, and the effects of these hazards on concrete elements are presented as resistance dimming parameters. The annual and cumulative losses due to these hazards in unit of currency are estimated using the life-cycle cost analysis. For decision making, the value of the expected cumulative cost associated with the retrofit or design scenarios is evaluated using a cost-benefit analysis. The results for a case study bridge, obtained from the framework proposed in the present study, indicated the significant impact of the different scenarios on reducing the expected value of damages or incurred losses due to multiple hazards. [ABSTRACT FROM AUTHOR]

The collection of infrastructure performance data is critical for agencies to cost-effectively maintain and preserve their existing assets. This paper presents a decision-support tool developed to support a state planning agency seeking to select a cost-effective data procurement strategy; specifically, the agency is considering whether to continue collecting and processing infrastructure performance data in-house or outsource to a third-party vendor. The probabilistic tool integrates uncertainty estimation via statistical methods and elicitation of expert judgement with Monte Carlo simulations to compute the probabilistic life-cycle cost of alternative data procurement strategies. For this particular case study, the expected cost to continue data collection and processing activities in-house is higher than the cost to outsource such activities. More importantly, the case study results lead to other important insights and contributions that are more generalizable to other contexts. For example, the labor resources required to collect, process, and maintain infrastructure condition data is the largest driver of total life-cycle costs for in-house data collection. Furthermore, because the decision to outsource data collection is made well before an agency selects a vendor, and such cost estimates are frequently unknown, there is a higher level of uncertainty and potential risk associated with outsourcing these activities. These conclusions, as well as the methods and framework presented in this paper, should assist planning agencies as they develop their data procurement strategy. [ABSTRACT FROM AUTHOR]

The 2030 climate and energy framework includes EU-wide targets and policy objectives for the period 2021–2030 of (1) at least 55% cuts in greenhouse gas emissions (from 1990 levels); (2) at least 32% share for renewable energy; and (3) at least 32.5% improvement in energy efficiency. In this context, the methodology of the cost-optimal level from the life-cycle cost approach has been applied to calculate the cost of renovating the existing building stock in Europe. The aim of this research is to analyze a pilot building using the cost-optimal methodology to determine the renovation measures that lead to the lowest life-cycle cost during the estimated economic life of the building. The case under study is an apartment building located in a mild Mediterranean climate (Castellon, SP). A package of 12 optimal solutions has been obtained to show the importance of the choice of the elements and systems for renovating building envelopes and how energy and economic aspects influence this choice. Simulations have shown that these packages of optimal solutions (different configurations for the building envelope, thermal bridges, airtightness and ventilation, and domestic hot water production systems) can provide savings in the primary energy consumption of up to 60%. [ABSTRACT FROM AUTHOR]

Seismic performance of a representative single-story confined unreinforced masonry school building in Tehran, Iran is evaluated by means of incremental dynamic analyses according to FEMA P-58 framework. For this purpose, fragility curves are derived for each of the constituent walls of the building. The in-plane behavior of the walls is considered only. Both flexible and rigid diaphragm conditions are investigated. For comparison purposes, the corresponding unconfined building exactly duplicating the considered confined unreinforced masonry building is also studied. In order to analyze the effects of near-source seismic actions on the performance of masonry buildings, two separate far-field and near-field ground motion sets containing 326 records are used. By utilizing the results of the incremental dynamic analyses and the available data of unreinforced masonry school buildings in Tehran, a scenario-based risk assessment of this type of school buildings is performed considering all three adjacent faults for three different earthquake magnitudes. Considerable performance improvement is achieved by providing confinement to the walls which leads to over $100 million reduction in the damage costs for masonry school buildings in Tehran. Also, significant reduction in seismic vulnerability, especially for unconfined masonry buildings, is observed by providing the roof with more rigidity. The findings in this study can be of direct use for disaster management of masonry school buildings in Tehran and similar cities. [ABSTRACT FROM AUTHOR]

New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment. Thus, equipment is often installed without taking into consideration the potential economic and energy savings of installing space and water-heating equipment combinations. In this study, we use a life-cycle cost analysis that accounts for uncertainty and variability of the analysis inputs to assess the economic benefits of gas furnace and water-heater design combinations. This study accounts not only for the equipment cost but also for the cost of installing, maintaining, repairing, and operating the equipment over its lifetime. Overall, this study, which is focused on US single-family new construction households that install gas furnaces and storage water heaters, finds that installing a condensing or power-vent water heater together with condensing furnace is the most cost-effective option for the majority of these houses. Furthermore, the findings suggest that the new construction residential market could be a target market for the large-scale introduction of a combination of condensing or power-vent water heaters with condensing furnaces.

The conventional methodologies for the design of flexible pavements are not adequate in providing solutions that meet the diverse sustainability challenges. Therefore, developing new methodologies and frameworks for the design of flexible pavement has become a priority for most highway agencies. On the other hand, there is no sound sustainable flexible pavement framework at the design phase that considers the key engineering performance, environmental impact, and economic benefits of sustainability metrics. Hence, premature failure of flexible pavements has become a common problem leading to a growing demand for sustainable pavement. Pavement engineers need to have access to tools that permit them to design flexible pavements capable of providing sustainable solutions under various complex scenarios and uncertainties. Hence, the objective of this study was to develop a resilience analysis framework, probabilistic life cycle assessment (PLCA) framework, and probabilistic life cycle cost analysis (LCCA) framework as the pillars of sustainability. These frameworks were used to develop a single sustainable flexible pavement design framework. The developed framework enables highway agencies to effectively quantify the lifetime sustainability performance of flexible pavements during the design phase in terms of resilience, environmental sustainability, and economic sustainability; and it allows to select the optimum design by comparing alternative design options. The framework will enhance the durability of flexible pavement projects by minimizing the cost, operational disturbance, environmental impact, and supporting the design. Many countries, especially those that fully dependent on the road network as the primary transportation route, may benefit from the sustainability-based road network design, which could ensure dependable market accessibility. The resilience of such a road network may reduce the cost of business activities by minimizing the interruption in surface transportation due to the functional and structural failures resulting from extreme events.

Efficient illumination of classrooms is one of many technologies that can help in constructing a cleaner future and have a positive environmental impact. However, the long-term economic plan of their implementation must still be created and validated. One promising technology is light-emitting diodes (LEDs) that have a low carbon footprint compared to conventional lighting sources. However, different studies barely mention lumen degradation, which is reduction in the illumination capacity throughout LEDs' lifetime. This paper investigates whether it is economically viable to switch fluorescent lamps to LED lamps while considering lumen degradation of both technologies, by considering the study case to be a classroom of a Kazakhstani university. The performance assessment was based on life-cycle cost analysis (LCCA). The required luminosity level, model lifetime (13 years) and classroom layout were the same for both technologies. The software RETScreen was used to develop the energy model and LCCA and the risk assessment of financial parameters. Simple and equity payback periods were found to be less than half of model lifetime with the internal rate of return reaching 20% and the electrical energy expenses decreasing by 10.95 kWh per year per m2 of the classroom, i.e., over 35%. The greenhouse gases (GHG) emissions dropped by 4.38 kgCO2 eq. per year per m2 of the classroom, which is over 30%. This analysis supports the advantages of using LEDs instead of fluorescent lamps, as a financially favorable decision that also reduces GHG emissions despite the high lumen deterioration of LEDs. [ABSTRACT FROM AUTHOR]

Electrical energy storage (EES) constitutes a potential candidate capable of regulating the power generation to match the loads via time-shifting. Optimally planned, EES facilities can meet the increasing requirement of reserves to manage the variability and uncertainty of renewable energy sources (RES) whilst improving the system operation efficiency and economics. In this work, the impact of intermittent RES on total production cost (TPC) is evaluated in the presence and absence of storage, using annual data regarding the non-interconnected power system of the island of Cyprus. Performing weekly simulations for the entire year of 2017, TPC is computed by solving the unit commitment based on a constrained Lagrange Relaxation method. Seven selected EES technologies are modeled and evaluated via a life-cycle cost analysis, based on the most realistic technical and cost data found in the literature. The results derived from the uncertainty analysis performed, show that zinc-air (Zn-air) battery offers the highest net present value (NPV). Lead-acid (Pb-acid) and sodium-sulfur (Na-S) are considered viable solutions in terms of mean NPV and investment risk. Lithium-ion (Li-ion) battery exhibits a particularly expensive choice. Dominated by its increased capital cost which still governs its overall cost performance Li-ion achieves a negative mean NPV far below zero. However, to strengthen the benefits derived from EES integration, further research and development is needed improving the performance and costs of storage. The uncertainty governing the majority of EES technologies, in turn, will be reduced, increasing their participation and RES contribution in autonomous power system operations. [ABSTRACT FROM AUTHOR]

The current design approach recommended by seismic codes is often based on the use of uniform-hazard response spectra, reduced to account for inelastic structural behaviour. This approach has some strong limitations that have been highlighted in many studies, including not allowing a direct control of the seismic risk and losses. This study aims at quantifying the levels of safety and the costs associated with this design approach, and to investigate alternative design approaches that have been developed in the last decades. In particular, a risk-targeting approach and a minimum-cost approach are considered. The first one, allowed by US codes, aims at designing structures with the same risk of collapse throughout regions of different seismicity. The second one aims to minimize the sum of the initial construction cost and the cost of expected losses due to future earthquakes. The comparison of the three approaches is performed by considering, as an example structure, a four-storey reinforced concrete frame building located in different areas in Europe, and by looking at the implications in terms of achieved safety levels, initial costs, and future losses. The study's results provide useful information on how the design criteria and the different hazard levels throughout Europe affect the cost and safety levels of seismic design. [ABSTRACT FROM AUTHOR]

Civil engineering structures can induce various environmental problems during their lifetime. In this paper, the life-cycle environmental impacts of structures, including the emissions to air, water and land, are quantified by environmental cost, and are considered as a part of indirect cost in the life-cycle cost (LCC) model. The computation of environmental cost based on the pollution prevention measures is presented. Using the environmental fines and taxes on various pollutants the environmental costs of construction materials, energy, transportation, and construction equipment are calculated. Structural type selection of a bridge structure is carried out based on the environmental cost-incorporated initial cost. The environmental cost-incorporated LCC model is applied in the life-cycle cost analysis (LCCA) of steel bridge girders. Hurdle discount rates are implemented on future environmental costs. Uncertainties arising from the direct cost and environmental cost are analyzed. The effects of different types of environmental cost discount rates are discussed. [ABSTRACT FROM AUTHOR]

Previous studies have shown that fractional derivative models present a plausible level of accuracy when it comes to capturing the behavior of viscoelastic dampers due to being capable of expressing the effects of excitation frequency and ambient temperature in viscoelastic damper parameters. Considering the possibility of earthquake occurrence during a structure lifetime, minimizing the life-cycle cost of a building is a practical way of optimizing the seismic design or retrofit plan and performance of the structure. In this paper, the total life-cycle cost of a structure with fractional viscoelastic dampers is chosen as the objective of an optimization problem while considering the effects of the changes in the ambient temperature and uncertainty related to the ground motion excitation which are the decisive parameters in the life-cycle cost analysis. The results for a 5-story steel frame show lower total life-cycle cost, initial cost, and story drift for the optimized structure compared to one with uniform distribution of dampers. Also, more use of dampers in optimized structure with life-cycle cost minimization objective, compared to a structure designed to minimize the cost of the dampers, has led to a significant reduction in the expected life-cycle damage costs. [ABSTRACT FROM AUTHOR]

Pavement design and management practices must be adapted in response to future climate change. While many studies have attempted to identify different methods to adapt pavements to future climate conditions, the potential economic impacts of the adaptations still remain largely unquantified. This study presents the results of a comprehensive life‐cycle cost analysis (LCCA) aimed at quantifying the potential economic impacts of a climate adaptation method, in which an upgraded asphalt binder (Performance Grade PG 76‐22) is used in the construction and maintenance of flexible pavement sections in lieu of the original binder (PG 70‐22) for improved resistance against high temperatures. For each of three major Virginia Department of Transportation (VDOT) districts with different climates, three case studies consisting of typical interstate, primary, and secondary pavement sections were considered. The LCCA accounted for the costs incurred during the mixture's production, maintenance, and use phases of the pavement life cycle by explicitly considering future climate projections, pavement life‐cycle performance, maintenance effects, and work zone user delays. The study concludes that pavements using the upgraded binder not only perform better over time but are also economically advantageous compared to those with the original binder under the conditions of the anticipated future climate conditions (2020–2039). [ABSTRACT FROM AUTHOR]

Heat transfer through building opaque envelope is responsible for approximately half of the total heat loss and gain to and from the surroundings. Therefore, insulation materials are commonly used in the building envelope to reduce the heat transfer. Recently, lightweight wall materials with lower thermal conductivity are used in construction along with the commonly used materials such as heavy concrete and earthen materials. In this perspective, there is a need to understand the optimum insulation thickness for different types of building construction materials to minimize unnecessary usage of insulation materials. This study investigated the optimum insulation thickness for different construction materials following a life-cycle approach, where an analytical optimization methodology based on the degree-days method and life-cycle cost analysis was used. In total, 4 insulation materials and 15 building construction materials were considered in the optimization study. The objective function was to minimize life-cycle cost corresponding to the decision variables including insulation thickness and the thermal conductivity of insulation and wall materials. The results showed that the use of insulation in lightweight wall materials is not economically feasible because of their negligible cost-saving potential (below US$2.5/m2-year). However, the walls with heavy concrete and earthen materials that have high thermal mass must be insulated due to their highest cost-saving potential (US$14–26.39/m2-year). [ABSTRACT FROM AUTHOR]