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Roadworks design: study on selection of construction materials in the preliminary design phase based on economic performance
International Journal of Construction Management
Abstract
The preliminary design phase transforms the investor’s ideas and information into general plans, drawings and specifications and helps the project managers continue the next steps in the projects. Material selection is an essential task to incorporate sustainable content into the construction industry. This paper reviewed materials selection studies and proposed a comprehensive method to compare the economic performance of construction material alternatives in this phase. The article constructed a life cycle costing equation used in the preliminary design stage that compared the total expected cost of the alternatives throughout the road construction project life cycle. The proposed life cycle cost method was divided into two scenarios according to the available information in the preliminary design phase and the material-dependent costs. A case study in Vietnam about the selection between baked bricks and concrete bricks was presented to demonstrate the proposed equations and models. The result showed that the baked bricks took the top priority due to the differences in cost items (e.g., transportation costs). Furthermore, to validate the models, they were applied to compare the expected and actual cost of 18 road construction projects in Vietnam – the differences are all below 10%. Further research may focus on building a database of models by applying the Building Information Model (BIM).
Knowledge management (KM) is imperative for the successful completion of complex projects. This research, which constitutes a recent doctoral dissertation, centers on exploring the KM practices of internal project stakeholders in managing emergent events within construction projects during the construction stage. Herein, a qualitative approach was utilized. Twenty-five semi-structured interviews were conducted with experts from five internal project stakeholders. A thematic analysis was subsequently conducted using NVivo12 qualitative data analysis software. This study identified a total of eleven types of events categorized into four major themes. Furthermore, the analysis highlighted KM mechanisms applied by construction project stakeholders to overcome the events. In the emergent events context, personalization techniques, such as face-to-face meetings and discussions, are more effective for problem-solving. This study aims to enable Vietnamese construction companies to understand the importance of different KM mechanisms in the emergent events context and offers recommendations on effective KM.
The main considerations in the early stage of architectural design are usually related to form and function. At the same time, with the growing concern regarding energy saving and carbon emission reduction, the parameters for the construction and physical quality of buildings are receiving more attention at the conceptual and schematic design stages. Diverse design options can emerge with the large number of variables to be considered in these stages. Moreover, the combined efforts to reduce buildings’ life cycle environmental impacts and cost, as well as the non-linear and often tradeoff relationship between the two objectives, make finding optimal design solutions for buildings’ life cycle performance complicated. Previous studies have established workflows to optimize buildings’ life cycle energy consumption, GWP, and/or cost; however, architectural design diversity has not been sufficiently discussed at the same time. In this study, a parametric optimization design process is established, aiming at minimizing the building’s operational energy consumption, life cycle environmental impacts, and life cycle cost. The setting of variables, as well as the workflows of the optimization process, is discussed from the perspective of both life cycle performance and architectural design diversity. A small-scale exhibition hall in China’s cold climate zone is selected as a case study. To approach the best design process applicable to this case, the optimal solution sets from different workflows under different variable settings are compared. The results show that by setting geometric and material variables in different steps in the entire optimization process, the resulting solutions can be a balance of architectural design and performance. In this case study, optimizing all of the design variables in one-step turned out to provide the best balance between design diversity and life cycle performance in the early design stage.
Increasing interests of circular economy (CE) principles applied into construction projects has led to the development of assessment methods for their justification. The use of smaller quantities of construction materials, materials of higher quality and durability, and recycling of construction waste are all requirements of today's aspiration for a circular economy, but it is necessary to assess their environmental and economic sustainability. This paper presents a review of the current assessment tools of circular economy projects applied to the construction industry, such as LCA, LCC and CBA. The main objectives of this study were to provide a categorization of CE concepts applied in the construction industry (CI) and to review assessment methods used for evaluating CE projects in CI. This paper selected and reviewed 96 published papers and classified them into one of five aspects of CE highlighted in this study: waste management, reducing the impact on the environment, material & product design, building design, and other. The results showed that the use of assessment methods in CE projects has increased in the recent years as well that an LCA was by far the most used assessment method and waste management the most common aspect of CE in CI.
Communication in the construction sector is complex, especially in the design phase, that if not properly handled, can reduce productivity. This topic is best studied in the United Arab Emirates (UAE) due to diverse religion, ethnicity and nationalities. The research in this area is considerably increased due to the rapid construction growth during the last two decades. In this context, this research investigates the importance of communication in the construction sector, especially in the design phase. It also investigates project managers' crucial role in utilizing communication referred to methods among their team members. A questionnaire survey was conducted where 146 respondents were collected and analysed using several statistical methods. Results revealed the importance of communication during the design stage. The most important channels of communication are those among the design team from different disciplines, then successively, consultant (site team) and contractor. The importance of best practices, such as hiring a coordinator between all design departments to reduce conflict and enhance communication, has been emphasized, and holding meetings is mostly the optimum method of communication.
Modular integrated construction (MiC) has recently been promoted by the advanced countries as an effective solution to 1) enable fast construction, 2) enhance the diminishing construction productivity, and 3) support sustainable development. In response to the COVID-19 pandemic, the completion of a MiC-based 1000-bed hospital in Wuhan, China, in less than a month, has made the world, especially sophisticated economies, 'talking' about this new technology. However, MiC is an ultra-modern technology that has both its merits and demerits; balancing out between them to maximize the opportunities that MiC has to offer needs insightful decision-making from higher authorities. Therefore, there is a vital need to understand and analyze the two contrasting but related matters, 'benefits and challenges of MiC' to help decision-makers in formulating better strategies based on informed choices. Past studies on MiC reported benefits in terms of time, cost, quality, safety, and environmental and social impacts, however, lack a holistic synthesis of MiC benefits by considering data from both the literature and real case studies. Whereas, the assessment methodologies used to prioritize MiC challenges did not consider the hierarchical nature of these challenges and their relative importance, which in turn impact the prioritization accuracy. This study contributed to bridging these gaps. Firstly, MiC benefits have been extensively explored by adopting a mixed research approach integrating literature synthesis, structured discussions, and real case studies. Then, a list of challenges was explored through literature synthesis and further validated and shortlisted through the first set of interviews from MiC experts. The second set of interviews was aimed mainly at evaluating the performance of MiC and providing recommendations for improvement from the international perspective. The interviews revealed that MiC should be treated as a long-term strategy and would not necessarily be a cheaper option in the short run, however, it would be a revolution in terms of time, quality, sustainability, safety, and life-cycle costs. Following the interviews, a questionnaire survey was conducted to prioritize the challenges using the multi-attribute group decision-making (MAGDM) approach, namely, Analytical Hierarchy Process (AHP), considering the hierarchical nature of challenges and their relative importance. The ‘road network capacity’ was found to be the most critical challenge. Finally, case studies were further carried out to reveal the measures that were adopted to mitigate the challenges in three international MiC projects. This research provides an interesting insight into the positive and negative aspects of using MiC for interested governments and construction stakeholders. It is anticipated that the benefits shall outweigh the drawbacks in the long run.
Over the last decade, transportation asset management practices have been increasingly enhanced through incorporation of sustainability considerations. Organizational- and network-level guidelines have been developed to assist transportation agencies in sustainability-driven highway network prioritization, but quantifying life cycle economic, social, and environmental impacts of highway treatment activities and projects using consistent, reliable data for informed project-level decision-making remains a challenge. This paper proposes a decision support framework to identify major life cycle economic, social, and environmental impacts of highway treatment activities and projects through integrating life cycle assessment (LCA) and life cycle cost analysis, allowing practitioners to determine the most appropriate project alternatives. Databases (e.g., RSMeans) and simulation models (e.g., Athena Pavement LCA and MOtor Vehicle Emission Simulator) were used to evaluate life cycle impacts from both the agency and user perspectives. Project alternatives using various sustainable/innovative techniques, including warm mix asphalt overlay, cold in-place recycling, full depth reclamation, intelligent compaction, and precast concrete pavement systems, were analyzed. Using the results of life cycle impacts following this framework, practitioners can better understand the implications of project-level decisions, perform what-if analysis to investigate trade-offs among alternatives, and achieve sustainability-related agency goals and objectives.
Prediction of construction cost and life-cycle cost through preliminary estimate is very important for the economic decision-making in the early phase of building projects. However, the conventional preliminary estimate has a high error range and low reliability because it relies only on the basic information of projects. In addition, the consideration of the life-cycle cost of the building is insufficient, causing problems such as budget shortage, inaccurate budgeting, and life-cycle cost increase. In this study, we propose a method of preliminary estimate based on BIM below the level of detail 2 and actual construction cost data to support the decision-making in the early design phase. To verify the proposed method, a web-based prototype was implemented and applied to three test cases. The range of error rate for three test cases was 1.93–7.16% (average error rate: 5.18%). It satisfies the criteria (−30% ~ +50%) of the “American Association of Cost Engineering”. As a result, the feasibility of the proposed model was validated. It is expected to be utilized as useful information in the decision-making occurring in the early design phase, and this allows for a rapid economic review of the design alternatives, a reduced LCC, and a shortened decision-making time.
Conceptual design is a key stage of product design. In order to make the design scheme have better greenness, this paper studies the automatic generation and decision-making technology of green demand-driven design. This paper mainly starts from the green demand of the conceptual design stage of electromechanical products, considers the introduction of green attributes into the product design information model, and builds an effective design space for electromechanical products. I This paper proposes an effective method for the low efficiency of current design schemes. The search strategy finally uses the genetic algorithm to complete the automatic generation of the design scheme. Considering the ambiguity and uncertainty of the design information, the LCA evaluation model based on the green feature is established, and the life cycle evaluation of the electromechanical products is completed. The effectiveness of the method is verified by an example of a car lift.
Transport infrastructures are a major drive for achieving economic development at all geographical scales, and particularly at the regional and local level, at which the units of the spatial economic systems are usually configured. In the current literature, a great number of studies have dealt with the relationship between transportation and economic development and a considerable amount of them have revealed different aspects of the transport infrastructures' contribution to the local and regional development, highlighting the complexity and the importance of this symbiotic relationship. Within this context, this paper discusses, in a theoretical context, this contribution and it develops an integrated framework for the conceptualization of how transport infrastructures contribute to the economic and regional development. This is achieved, first, by distinguishing the main categories of transport infrastructures and, secondly, by reviewing the established regional development and economics theories that build on the relationship between transport infrastructures and regional development. Further, the paper reviews the main factors affecting, either directly or indirectly, this contribution and the determinants of the size and direction of the effects transport infrastructures contribute to the economic and regional development. Overall, the paper highlights the importance of transport infrastructures policy as a tool of regional and economic policy.
Existence of diverse sustainable materials with distinctive features causes more difficult decision makings for project teams especially when it is intended to use ideal materials from diverse types of sustainable products. Few research studies have been conducted so far on applying Building Information Modeling (BIM) to act as Decision Support System (DSS) using of math works functions and tools in combination with Multiple Criteria Decision-Making (MCDM) techniques. The main purpose of this study is to propose a methodology that integrates BIM with decision-making and problem-solving approaches including Fuzzy and TOPSIS in order to efficiently optimize the selection of sustainable building components at the conceptual design stage of building projects. To select the optimum building components, each item is assessed against three major attributes of decision criteria as Design, Economic and Quality factors, which are applied in Multiple Attribute Decision Support System (MADSS) methodology to indicate the various performance of buildings sustainability. This BIM-integrated process is linked to the engine of Matlab software to apply Fuzzy functions on the users’ priority in order to automatically suggest the ideal solutions. The design alternatives suggested by Matlab is validated by Life Cycle Cost (LCC) method to analyze the operational cost of an actual building project. Using this innovative method will make the decision-making procedure more convenient as well as proposing more realistic and reliable final and sustainable optimized choice.
This article discusses the potential of introducing sustainability in the architectural design method so that building solutions can contribute to sustainable development. Sustainability has introduced a new pattern to the architecture practice, which involves important modifications in the teaching of architecture in what regards to the design methods to students but also practitioners, in order to provide more comfort for present and future generations. In the design phases of the architectural design, the subject of the three pillars of sustainability—economic, social and environmental factors—are not always considered by the architect in the decision-making process. The topic involves actions that will influence the overall performance of the building throughout its lifecycle. Sustainability has not been a priority in the training of the architect. The existing tools, Sustainability Assessment and Certification Systems, although adequate to evaluate the sustainability component of a building, do not prove to be the most appropriate tool to support architects during the design process. Therefore, the implementation and evaluation of strategies that integrate the sustainability principles need to be included in the early stages of the architectural design method. In addition to collecting data through literature review, a survey was conducted among 217 architects and architecture students in order to access the need for a tool that supports architects in the issue of sustainability. The results concluded that, although all the respondents agree about what concerns the implementation of sustainability principles in the architectural design method, only few respondents guarantee that these principles are implemented by means of a rigorous evaluation. Thus, the purpose of this paper is to identify a set of guidelines that can help architects to change the current approach of architectural practice towards more sustainable strategies in building design. This means the introduction, implementation and evaluation of sustainability principles in different phases of the architectural design method. The proposal stresses the main strategies that need to be considered in each phase of the architectural project and defines a level of recommendation in each guideline that allows the architect to evaluate the implementation of sustainability.
Project delivery methods are comprehensive processes whereby major designers, and constructors, and various other consultants will provide various services for the design and the construction of buildings in order to deliver a complete building or services to the owner (Migliaccio et al., 2008). The buildings cycle starts with the development of a basic idea or concepts originating from planning or pre-design phase (Pearce 2012). As such, the phase majorly focuses on defining the key elements of aesthetics, functional as well as physical requirements and constraints towards achieving the desired building. It will also involve the identification of any budget constraints, scheduling constraints, and also legal and regulatory constraints that must be taken into account during project design (Venegas 1987). Materials acquisition, and energy and waste from the building during the buildings life cycle contributes to the effects that buildings have on the site and surrounding environments and the greatest opportunity at which these can be influenced ultimately presents itself at the pre-design phase of the project before the facility has begun to take be built. Sustainability as defined by the Brundtland Commission defines sustainability as developments which meet the needs of the present without it being able to compromise the ability of future generations to meeting their own needs (Brundtland, 1987). This study focuses attention on pre-design process and opportunities for sustainability by stakeholders in Abuja to include Architects, clients, project managers and financiers. A quantitative method of research was adopted where questionnaires were administered to identified stakeholders. The data collected was statistically analysed with SPSS software. The expected contributions to knowledge are to reveal the enormous sustainability opportunities that exist at the pre-design stage to the stakeholders in Abuja, secondly to reveal the possibilities of sustainability to stakeholders in Abuja. Thirdly Suggestions would be highlighted of design features for a more sustainable building.
Based on the authors' combined experience of seventy years working on projects around the globe, Construction Equipment Management for Engineers, Estimators, and Owners contains hands-on, how-to information that you can put to immediate use. Taking an approach that combines analytical and practical results, this is a valuable reference for a wide range of individuals and organizations within the architecture, engineering, and construction industry. The authors delineate the evolution of construction equipment, setting the stage for specific, up-to-date information on the state-of-the-art in the field. They cover estimating equipment ownership, operating cost, and how to determine economic life and replacement policy as well as how to schedule a production-driven, equipment-intensive project that achieves target production rates and meets target equipment-related unit costs and profits. The book includes a matrix for the selection of equipment and identifies common pitfalls of project equipment selection and how to avoid them. It describes how to develop an OSHA job safety analysis for an equipment-intensive project, making this sometimes onerous but always essential task easier. The authors' diverse and broad experience makes this a book that ranges from the rigorous mathematical analysis of equipment operations to the pragmatic discussion of the equipment maintenance programs needed to guarantee that the production predicted in a cost estimate occurs.
This paper presents the total cost and cost distribution between activities required for the construction of reinforced concrete underpass bridges. The required material quantities of concrete, reinforcing steel, earthworks (excavation, soil improvement layer and backfilling), waterproofing works, joint formation and drainage system from 34 closed box section and slab frame underpasses from recent highway projects in Greece are statistically processed. Following analysis of this data, preliminary cost estimating formulae for underpass bridges are proposed based on the overpass deck surface area and a new parameter called the theoretical volume. The theoretical volume is a known value even at the preliminary stage of design as it is essentially the dimensions of the local road that must be realigned to underpass the motorway. It is suggested that the use of the proposed formulae will provide decsion-makers with accurate cost estimated of reinforced concrete motorway underpass bridges.
One of the challenges in sustainability analysis and its development is the optimum selection of sustainable materials to meet the project's requirements while doing sustainable design. This can only be achieved when project team adopt the use of a strategic approach while selecting the materials, although this could be a complex task for decision makers. Building Information Modeling (BIM) offers designers the ability to assess different design alternatives at the conceptual stage of a project. As a method of integration and through its modeling techniques, BIM can be used to assess the impacts of design alternatives on the energy saving of buildings all over their life. Furthermore, BIM has the potential to help designers select the right type of materials during the early design stage, and make vital decisions when selecting the materials that have sustainable impact on the building's life cycle. The main purpose of this study is to propose a methodology that integrates BIM with decision-making problem-solving approaches (i.e. Entropy-TOPSIS) in order to efficiently optimize the selection of sustainable building components at the conceptual design stage of building projects. Therefore, a Decision Support System (DSS) is developed by using Multiple Criteria Decision Making (MCDM) techniques to aid the design team decide on and select the optimum type of sustainable building components and design families while doing conceptual design of proposed projects, based on three main criteria (i.e. environmental factors, economic factors-"cost efficiency," and social well-being) in an attempt to identify the influence of design variations on the whole building's sustainable performance. The multi-criteria procedure embedded in the DSS relies on numerical models to simulate alternative situations, as well as ranking the alternatives and select the best ones based on both the owners' strategic preferences and the availability of sustainable materials in the market. The set of models included in the DSS describes the relationship between sustainability criteria, manufacturers' sustainable materials and the interactions between project team that take place during the design of sustainable building projects. This paper aims at exposing the feasibility of using BIM for analysing the life cycle costs of sustainable buildings at the conceptual stage. The design alternatives suggested by the DSS are evaluated in an integrated environment that joins BIM concept and Life Cycle Cost (LCC) method to analyze the operational cost of the whole building. An actual building project is used to validate the workability and capability of the proposed methodology.
This article addresses two critical issues associated with reliability and maintenance of building services systems. The first is the ratio of operating and/or maintenance costs to initial costs for building services systems. It is an important parameter for life cycle costing and maintenance policy development. The second is the proportion of items among building services systems that need preventive maintenance. In this article, the example used is to estimate the ratios based on a cost dataset. Correctly estimating the ratio is important, but using a constant ratio in life cycle costing may result in wrong decisions. The proportion of preventive maintenance for building services systems is estimated on the basis of the distribution of failure patterns.
To be found on http://www.eranetroad.org/index.php?option=com_content&view=article&id=111:2011-energy&catid=31:standard&Itemid=46 under LICCER - Life Cycle Considerations in EIA of Road Infrastructure
A significant share of federal and regional infrastructure budgets is spent on constructing, maintaining, repairing, and replacing road infrastructure. Due to its magnitude, sustainable road construction practices can support national sustainable development goals (e.g. The Federal Sustainable Development Strategy of Canada). However, the quest for sustainable road construction practices has been hindered by the lack of expertise, information, and resources. The advent of building information modeling (BIM) provides more extensive access to functional and physical data of construction material. Published literature has overlooked BIM-based methods that facilitate the life cycle sustainability evaluation of road construction techniques. This paper presents a methodological framework for life cycle thinking-based road infrastructure evaluation. This framework compares the life cycle sustainability performance of alternative road pavement construction methods. A BIM-based visual program has been created to automate the proposed framework. The program was demonstrated by comparing three road construction methods for a collector road. Results indicated that geomembrane road is the best solution based on the triple bottom line of sustainability. The proposed Life cycle Sustainability Assessment (LCSA) framework, a BIM-based tool, and the implementation road map will assist infrastructure managers in selecting the most sustainable road construction method that will consequently support United Nations Sustainable Development Goals (SDG).
This paper focuses on the multi-objective optimization of building envelope parameters in order to enhance the energy and economic performance of buildings. The study carried out for the climates zoned as; cooling dominated and heating dominated. All possible solution scenarios (more than 13 million) that might be encountered in practice, were included in the optimization process. Two conflicting objectives were pursued: to minimize overall thermal energy need and to lower the initial investment cost of the building envelope. NSGA-II genetic algorithm was implemented via developed code in Matlab environment and convergence time of that was shortened. Pareto-Front solutions were presented for two provinces (Osmaniye and Erzurum) of Turkey and life cycle costs of the Pareto-Front solutions have been compared, after the envelope optimization process. The results clearly showed that, the appropriate selection of the building envelope parameters at the preliminary design stage could significantly reduce life cycle cost, beside providing better solution options for zero energy buildings.
All costs within the life cycle of a building are known as its life cycle cost (LCC). In the design process of a building, the use of a lower initial cost index to select an option among others with similar performance may not lead to an economically optimal alternative during the life cycle. Hence, today, building designers and investors require a tool to estimate life cycle cost at the conceptual design stage to select an economically efficient option. Resilient solutions generally lead to a higher level of complexity and upfront costs and carry additional embodied environmental impact as well. This study aims to support the design of resilient buildings using a sound LCC methodology in the preliminary design stage. The research aims to integrate LCC capabilities directly into a Building Information Model (BIM) and increase the economical relevance and scientific robustness of LCC indicators towards better LCC cost optimization. The plugin, which is developed in the BIM tool is represented to use cost and resiliency factors to predict the whole process cost of building projects to assist designers in selecting a cost-efficient and resilient design option. The LCC of a building includes its initial cost, repair and maintenance cost, operating cost and salvage value at the end of the building's useful life, and all of which were considered in the estimation. The earthquake expected failure and human fatality cost are calculated to consider the resiliency index in building design. The application of the proposed framework to design a residential building is developed and validated on two design options. The application of the actual building project illustrates that by increasing the initial cost in the second alternative by 4.6%, its annual expected failure cost is decreased by 35.4%, and its total life-cycle cost is reduced by almost 10.4% within the first 45 years of operation. The reduction in the cost of the building and human fatality due to failure during an earthquake means the building's resilience would be improved. Using the developed plugin, designers could estimate LCC of the buildings at the early design stages and design more resilient buildings with better economic performance in its life cycle according to the proposed indices.
As a derivative demand of economic development, freight transport plays an important role in economic growth. In recent years, the experience of some countries shows that freight demand remains stable or even declines with GDP growth. This study uses the panel data of 30 provinces (cities and autonomous regions) in China from 1997 to 2017 to analyze the evolution of the relationship between freight demand and economic development, using the decoupling index and transport intensity measurement models. We find that there is an inverted U-shaped relationship between the turnover of freight traffic per person and economic development, and the development processes of Beijing, Shanghai, and Tianjin fully conform to this feature. China's economic development as a whole is decoupled from freight development, while its transport intensity is weakening; however, there are obvious regional variations. This indicates that the contribution of high freight-demand sectors to economic development has declined, which is undoubtedly the result of multiple factors such as the industrial structure and geographical characteristics of each region. This study provides an opinion in support of region-dependent infrastructure improvements, for managers to realize the “win-win” development of transportation and the economy.
Construction Cost Index (CCI) is calculated monthly and published by Engineering News-Record (ENR). CCI is utilized for capital project budgeting and construction cost estimation, especially in cases where mid- and long-term forecasts are needed. Accurate prediction of CCI helps avoid underestimating and overestimating project costs but the current prevailing time series prediction models do not show promising results, especially in mid- and long-term forecasting. The capability of two machine-learning algorithms, k nearest neighbor (k-NN) and perfect random tree ensembles (PERT), are utilized to enhance CCI forecasting, especially in the mid- and long-term. The proposed machine-learning algorithms are able to significantly enhance the predictability of forecasting CCI in all the scenarios, short-, mid-, and long-term. Data from January 1985 to December 2014 is collected from ENR and bureau of labor statistics to conduct empirical studies and quantitatively measure the performance of the proposed methods. As the outcomes show, the prediction accuracies of both proposed methods are better than those of current prevailing time series models under all the tested scenarios. It is anticipated that cost estimators can benefit from CCI forecasting by incorporating predicted price variations in their estimates and preparing more-precise bids for contractors and developing more-accurate budgets for owners.
Capital project benchmarking requires an effective cost normalization process to achieve reasonable comparisons of cost-related performance for projects that are executed at different times and locations. Traditionally, cost normalization approaches were developed for ex post facto analysis of project performance and assume that all required information is fully available from a completed project. However, practitioners have expressed the need for cost normalization techniques to evaluate phase-level outcomes during ongoing projects. This paper aims to provide a cost normalization framework tailored to phase-based performance assessment. The framework involves three main steps: currency conversion, location adjustment, and time adjustment with considerations for various scenarios where the required information is not fully available. Case studies are conducted to demonstrate how the proposed cost normalization framework has been applied to phase-based performance assessment for capital projects. The proposed framework can benefit both researchers and industrial professionals interested in cost estimation, feasibility analysis, and performance assessment.
Life cycle cost analysis of maintenance costs and budgets for university buildings is essential. This paper briefly describes the meaning and application of the standard of maintenance costs and budgets, and addresses the meaning of maintenance cost and budgeting with regard to engineering. To examine this issue, a case study on the operations maintenance phase of four university buildings on the campus of National Taiwan University is presented. Using historical data on maintenance and repair over a 42-year period, a cost prediction model using the life-cycle cost (LCC) was determined using three different methods: (1) simple linear regression (SLR); (2) multiple regression (MR); and finally (3) a back propagation artificial neural network (BPN). The research results showed that the BPN model had good estimation ability. This paper implemented the BPN model in a case study to analyze the problems of maintenance costs and budgeting for university buildings. The study helps to set a legitimate standard for predicting repair maintenance costs, and proposes a plan and standard for the repair maintenance strategy of structures. The results of this study are provided to show how to establish a cost prediction model of maintenance and how these university buildings can be used to obtain the optimal life cycle maintenance scenario.
Product performances are directly influenced by both classical and non technical properties of the materials used. That is why Material Selection Process (MSP) is an important part of the design process. The objective of this paper is to show that existing material selection approaches including mechanical and environmental criteria are not enough complete to make optimal material choice in preliminary design phase. Indeed, in this design phase, it is necessary to do the best choice in order to optimize technical and economical requirements of a component while reducing the product Environmental Impact (EI) in the whole Life Cycle (LC). Another LC approach is proposed here, including material in several life cycles and influencing the material selection process.
This study endeavours to establish an internationally recognised methodology to undertake comparative assessments of the relative ?sustainability? of buildings and in future civil engineering projects. The methodology devised (in particular the materials database of environmental impacts) to achieve this, has been specifically tailored to Hong Kong?s Construction Industry, and thereafter with some further development will be applicable to the broader South East Asia Region.
Hong Kong and the South China region are strongly driven by costs so, in this context, Life Cycle Costing (LCC) sometimes referred to as Whole Life Costing, must be included in any assessment. Life Cycle Costing (LCC), together with Life Cycle Assessment (LCA) are the sustainability impacts measured. Therefore in this study, two of the three recognised environmental aspects of sustainability are measured: economics and environment. Social impacts were omitted because at present there is not an established consensus of which social indicators are relevant and the relative weighting between each of these and between the economic and environmental impacts measured.
The study compared the environmental and cost performance of the following three 40-storey residential tower types:
?a housing authority ?standard? harmony block (HAB),
?a private sector housing block (PSB),
?and the Integer Concept Tower (ICT) (50-year and 75-year life).
The results show that longevity is important and the ICT becomes the best performer over all the indicators in the 75-year life assessment. The presumption here is that it will in reality have a 75-year life because of its intrinsic flexibility of its frame construction, where as the inherent inflexibility of the other two buildings will limit their life spans to just 50 years before they become redundant. The results also show that the operational regime is significant for all buildings. Energy efficiency is clearly important and strategies to reduce demand and increase supply from renewable energy generation sources should be examined. The repair and maintenance regime is also very significant indicating that varying and improving how the building is run and maintained could greatly reduce the overall life cycle impacts. The Integer Concept Tower is definitely worthy of further investigation.
Engineering design relates to the design of engineered artifacts formed by materials of various types. Materials play an important role during the entire design process. At the early design stage, materials may achieve some of the required functions. Hence, designers may need to identify materials with specific functionalities in order to find feasible design concepts. ‘Materials identification’ is used to refer to this materials-related design activity. At the downstream design stages, when the physical structure for a design has been determined, materials with specific properties should be selected from a set of candidates, which is commonly referred to as ‘materials selection’.In this paper, an overview of recent research in materials identification and materials selection is conducted, that provides materials support for the early and downstream stages of engineering design respectively. The purpose of this work is to provide a documentary of latest research efforts in this area, to recognize the importance of materials identification and selection for engineering design problem solving, as well as to propose prospects of future research, so that more effort can be spent on those lacking materials-related research.
Nowadays, few measures have been carried out to improve the relationship among construction site activities, the environment and the citizens. Maybe due to the mobility of the construction activity, it is difficult to make the construction companies especially the smallest ones keep the law. There are some good examples but they are still insufficient. The production of legal documents that encourages a more environmentally positive behaviour, that is, that arouse and force the construction industry to handle its debris and by-products more carefully, is of vital importance to the contribution of this sector for sustainable development for the which all must contribute. In this context, special mention must be made to the mandatory, in public projects, of a waste management plan, which must be made during the design stage. It seems to be a correct and effective way to highlight the importance of waste management and to get all the participants involved, from the design to the construction stage. This change, however, must be accompanied by public awareness campaigns. It is not enough to stress that the plan is mandatory. The plan's importance must be addressed too. It will be easier to reach our goals if all kwon the advantages and importance of such a plan. Due to the need for adaptation and improvement of existing buildings taking into account the new standards of quality and comfort, the works involving demolition of buildings or parts of buildings are becoming increasingly frequent in Portugal. Thus, the study of practical solutions that point to the reuse of building materials and components, will contribute to decrease the urban problem created by illegal landfills bringing
Estimating in building construction: International Edition
- F R Dagostino
- S J Peterson
ISO 15686-5:2017: building and construction assets - service life planning - Part 5: life cycle costing standard as a guideline. Geneva: International Organization for Standardization
- Iofs Iso
- Iso IOFS
3.1-Transportation and Economic Development. The Geography of transport systems
- J-P Rodrigue
- T Notteboom
Estimating in building construction: International Edition
- S J Dagostino Fr Peterson