Analysis of the implementation of effective waste management practices in construction projects and sites

In this paper, the implementation of effective waste management practices in construction projects and sites is analyzed, using data from a survey answered by 74 Spanish construction companies based in Catalonia. Most commonly implemented practices were found to be on-site cleanliness and order, correct storage of raw materials, and prioritization of the nearest authorized waste managers. The least widespread practices were the use of a mobile crusher on site, the creation of individualized drawings for each construction site, and the dissemination of the contents of the waste management plan to all workers, to help them to meet its requirements. Waste regulations for construction and demolition, and the corresponding construction waste management facilities, were designed before the recession in the Spanish construction sector. Current waste generation rates are still below predicted levels, and the infrastructure was designed for five times more waste generation. Even so, the percentage of reused and recycled waste currently amounts to 43%. Survey respondents highlighted various instruments and measures that would make the management of construction and demolition waste more sustainable. Most of the opportunities identified by construction firms are within the scope of government and related to a combined system of bonus and penalties and the establishment of environmental awareness and training programmes for all the stakeholders. Within the scope of authorized waste managers, firms suggested improvements such as the standardization of fees, a reduction of the time until the issue of waste management certificates, a higher number of inspections, and a change in the current model of a few large construction waste management facilities. This research is useful to better understand the current status of construction and demolition waste management in construction projects and sites. Thus, the results of this research will guide policy makers and relevant stakeholders such as contractors, clients, architects and engineers to achieve the EU target of recovering 70% of construction and demolition waste in 2020. In this sense, reliable information can help governments and professional associations to set future C&D waste management regulations, training programmes and dissemination tools, inspections, etc.     

The use of materials from demolition in construction

The author looks at economic and technical factors involved in the reuse of materials from demolition within the construction industry. Past experience in the use of such materials is reviewed and the results of a survey of the present usage of demolition materials in this country are presented. The prospects for increased utilisation are discussed in the light of the need to ensure the durability of building materials made from them.     

建筑废弃物再生利用的可行性技术研究综述

建材行业的发展为城市化建设提供了重要保障,在我国城市化快速发展、建筑材料需求旺盛的带动下,建材行业发展强劲,但大多属于高能耗高污染行业,加之城市拆迁改造产生大量建筑废弃物,环境压力十分巨大,必须加强建筑废弃物的环境管理。对建筑废弃物再利用、再循环以及减少建筑废弃物是解决建筑行业环境问题的重要方式,实施这些仍有很大的提升空间。本文回顾了近年来建筑废弃物再生利用方面的各种可行性技术。主要是针对沥青、砖、混凝土、金属、玻璃等几种物质再生利用的可行性技术进行综述,为未来建筑废弃物再生利用领域提供参考。     

Retrofitting residential building envelopes for energy efficiency: motivations of individual homeowners in Israel

The willingness of private individuals in Israel to invest in energy-saving retrofit of the envelope of residential buildings was studied by means of a survey. Responses show that awareness of the need to conserve energy is high, but that willingness to participate in a retrofit project is modest and is limited to relatively small outlays. The decision on whether to retrofit at all, and then how much to invest in the project, is characterized as a two-stage process in which different factors may affect the outcome of each of the two stages. The major barrier to building retrofit is the perception (justified, in most cases) that the direct economic benefit to the homeowner from the resulting energy saving is small, and that given Israel's relatively mild climate, the payback period is very long. The stamp of approval provided by a government subsidy of 25% would have a large non-proportional effect on willingness to undertake building retrofit. Funding for the subsidy could be obtained from a Pigovian levy on electricity, applied for a limited period, and its environmental benefits outweigh the cost of the subsidy itself.     

Critical analysis of the waste management performance of two uranium production units in Brazil--part I: Poços de Caldas production centre

Waste management strategies in mining projects will depend to a large extent on the characteristics of the operational process, the type of ore and prevailing socio-environmental conditions, amongst other issues. The expenditures required by the management scheme and the implementation of remediation programs will be determined by the extent that the above issues were considered in the planning phase of the project. Several works have been published in the literature concerning the analysis of waste management programs and environmental impacts associated with uranium projects around the world. However, the vast majority do not report a comprehensive assessment integrating the various relationships among operational process, environmental impact, remediation strategy and costs. This study, divided into two papers, presents a detailed critical analysis of the waste management strategies adopted in two uranium production centres in Brazil, i.e., the Poços de Caldas Project (Part I) and the Caetité Project (Part II). The operational processes are described and the environmental impacts of the generated wastes as well as the adopted management strategies and costs are examined. Also, in Part II, a comparison between both production centres is made emphasizing the impacts of environmental and social-economical issues on the overall assessment.     

Best practice measures assessment for construction and demolition waste management in building constructions

Currently the construction and demolition (C&D) waste collection system in Spain is managed in a decentralized manner by each sub-contracted company. This lack of comprehensive strategy for C&D waste management causes a confusing and sometimes individual attitude regarding the different measures for C&D waste. Therefore effective waste management should be enforced. Construction stakeholders have wide range of best practices in C&D waste management that can be implemented, so they need to be assessed for their effectiveness.The aim of this research study is to assist construction stakeholders in making a decision on C&D waste management. This paper carries out a survey conducted among the construction agents in order to evaluate the effectiveness of 20 best practice measures regarding C&D waste management, identifying the most suitable types of building constructions to implement these practices and also the advantages and drawbacks of their performance in a building construction project.Results of this study show that among the highly effective best practices are: the use of industrialized systems and the contract of suppliers managing the waste. In addition, distributing small containers in the work areas is also another high valued practice, although only 36% of respondents usually implement this measure in their works.     

Use of recycled products in UK construction industry: An empirical investigation into critical impediments and strategies for improvement

Construction industry consumes about half of all material resources taken from nature, and generates a large portion of waste to landfill. A way of tackling negative environmental impacts impending from continuous material extraction and waste generation is the use of recycled materials for construction projects. However, the use of recycled materials is yet to become a commonplace in construction industry. This study evaluates the factors hampering the use of recycled products in UK construction industry as well as strategies that could be adopted to enhance its use in the industry. In order to identify the impediments and critical strategies, a two-fold methodical approach was used. An unstructured interview preceded a quantitative questionnaire survey which was used to elicit broader industry practitioners’ opinion.The study shows that designers rarely specify recycled products. This is due to lack of adequate information about quality and market availability of the products, negative perception from clients, and unexpectedly high cost of the products, despite its perceived low quality. The study suggests that a number of strategies could be adopted to promote the use of the products. These include allocation of points to the use of recycled products in sustainable design appraisal tools, governments legislative measures, improved collaboration between designers, contractors and materials suppliers, contractors involvement at earlier stage of design, improved education of the professionals about the products, and the use of tax break to influence the cost of the products. The findings of this study would therefore help policy makers, manufacturers and construction professionals to identify the factors hampering the use of recycled products for construction projects as well as the strategies that could be adopted in order to create market for the products.     

The importance of local context in the planning of environmental projects: examples from two biogas cases

The planning of facilities to improve the environment is often carried through in the form of locally based construction projects. These projects can be complex, involving a variety of issues and a number of different actors from both the public and private sectors. By drawing on previous research on project planning, an analytical model for analysing the issues connected with the planning and implementation of environmental projects is developed. The main argument of the paper is the importance of considering how context-specific factors affect project design and project management. The empirical material is taken from the planning of two biogas projects in Sweden and it is showed how differences in factors such as the actors involved, the organisational framework and the political setting lead to two markedly distinct planning approaches. The results of the paper, which also highlight the importance of a flexible planning approach, are relevant not only for biogas but also for other projects with similar characteristics.     

Sustainable management of demolition waste—an integrated model for the evaluation of environmental, economic and social aspects

A model is presented for evaluating waste management systems for their contribution to a sustainable development, including environmental, economic and social aspects. The model was tested in a case-study, where groups of long-term unemployed people were offered both education on environmental issues and practical work with the recovery and recycling of building and demolition waste as a form of vocational development. Application of the suggested model revealed the overall effects on sustainability of different methods of waste management. In addition, negative aspects of the systems analysed were identified, which led to discussions about possible improved practices within the waste management systems. Two of the waste management systems investigated (the recycling of steel and re-use of sanitary porcelain) showed a potential contribution to sustainable development in all of the aspects studied. Preparing bricks for re-use showed the largest potential for eco-efficiency, but had negative effects on sustainability from the social perspective of health and the working environment. The possibility of further use of the model and the remaining obstacles to such analyses are discussed. One observation is that the data collection needed to perform this kind of sustainability analysis is resource-demanding, and that it would therefore be better to identify a smaller number of key indicators.     

建筑废弃物的回收原理与方法研究

由于社会和经济因素的要求,当今的建筑生命周期要最大程度地完成圆形的循环过程,即重新使用拆建物料制造新产品。循环经济的大背景下,承建商通过坚实的理论基础,采用分层次的方法来进行建筑废弃物的管理。文中总结了两种方法的优点和缺点,进行了混合回收与源头分离两种方法的比较研究。最值得注意的是两个不同的意向方案:绿色星球计划和ICC-ESSAVETM方案。突出的可持续认证和设计方案及绿色星球计划侧重的能源效率模型时常被繁重调试系统的LEED所青睐。一旦被国际编码理事会所批准,这些文件可以在LEED的评分系统下或绿色星球计划中,帮助其寻找资格评分。文章最后分析了建筑废弃物的回收流程,并得出结论:高达95%的建筑和拆迁建筑废弃物都可以回收;回收相比垃圾填埋更节省资金;源头分离较混合回收需要更多的管理和劳动力,但能获得更大的经济利益;承建商应该组织和管理现场的回收工作。     

Determinants of privatized solid waste management service provision in Lagos

The growing popularity of privatized solid waste management service in least developed countries warrants an exploration of factors that are likely to impact on its sustainability. This study takes integrated solid waste management approach by analyzing relevant issues on both market sides. We use a three step theme development sequence to analyze the data obtained on service providers through library research, observations and interviews. This was followed by an opinion survey on the demand side to elicit households’ support for service improvement. Findings show that source-separation issues, government enforcement, market segmentation, financial issues and waste disposal issues are key factors influencing improved service provision. Meanwhile, on the demand side, we found that households are willing to support proposed regulatory improvement in service provision. Thus, we suggest industrial stakeholders to consider the aforementioned supply side issues in designing future service improvements that will take advantage of existing demand side feasibility.     

Critical factors in effective construction waste minimization at the design stage: A Shenzhen case study,China

Construction waste minimization at the design stage is a key strategy in effective waste reduction. However, it seems that few studies focus on exploratory factors that can significantly improve the design of construction waste minimization. This paper addresses this research gap by presenting a set of critical factors that inform and improve the practice of waste minimization design, particularly in the context of Shenzhen, China. Nineteen potential factors which can influence effective waste minimization are presented based on related official guidelines, reports and literature. Top institutions in Shenzhen that have received a Grade A building design certification were surveyed through a questionnaire. From this survey, six critical factors are derived: (1) large-panel metal formworks, (2) prefabricated components, (3) fewer design modifications, (4) modular design, (5) waste reduction investment and (6) economic incentive. The applicability and significance of the identified critical factors for effectively designing waste minimization are also explored. These critical factors not only provide designers and project managers with a useful set of criteria for effective design strategies to reduce construction waste, but also serve as valuable references for the government to formulate related construction waste minimization regulations.     

Security risks in nuclear waste management: Exceptionalism,opaqueness and vulnerability

This paper analyses some potential security risks, concerning terrorism or more mundane forms of crime, such as fraud, in management of nuclear waste using a PEST scan (of political, economic, social and technical issues) and some insights of criminologists on crime prevention. Nuclear waste arises as spent fuel from ongoing energy generation or other nuclear operations, operational contamination or emissions, and decommissioning of obsolescent facilities. In international and EU political contexts, nuclear waste management is a sensitive issue, regulated specifically as part of the nuclear industry as well as in terms of hazardous waste policies. The industry involves state, commercial and mixed public–private bodies. The social and cultural dimensions – risk, uncertainty, and future generations – resonate more deeply here than in any other aspect of waste management. The paper argues that certain tendencies in regulation of the industry, claimed to be justified on security grounds, are decreasing transparency and veracity of reporting, opening up invisible spaces for management frauds, and in doing allowing a culture of impunity in which more serious criminal or terrorist risks could arise. What is needed is analysis of this ‘exceptional’ industry in terms of the normal cannons of risk assessment – a task that this paper begins.     

Formulating a coastal zone health metric for landuse impact management in urban coastal zones

The need for ICZM arises often due to inadequate or inappropriate landuse planning practices and policies, especially in urban coastal zones which are more complex due to the larger number of components, their critical dimensions, attributes and interactions. A survey of literature shows that there is no holistic metric for assessing the impacts of landuse planning on the health of a coastal zone. Thus there is a need to define such a metric. The proposed metric, CHI (Coastal zone Health Indicator), developed on the basis of coastal system sustainability, attempts to gauge the health status of any coastal zone. It is formulated and modeled through an expert survey and pertains to the characteristic components of coastal zones, their critical dimensions, and relevant attributes. The proposed metric is applied to two urban coastal zones and validated. It can be used for more coast friendly and sustainable landuse planning/masterplan preparation and thereby for the better management of landuse impacts on coastal zones.     

Assessing the accumulation of construction waste generation during residential building construction works

The difficulty of dealing with construction and demolition waste (CDW) on construction sites is not new and continues to be an environmental problem. Understanding the waste generated in a construction work is essential to optimize CDW management. Therefore, any tool used for establishing an estimation of the CDW that will be generated should be considered as an alternative to achieve real solutions pursuing sustainability. This paper presents the evolution of CDW flow generation in the construction of new residential buildings, and has identified that the construction activity is increasing the waste generation. In an attempt to find some solutions and provide improved alternatives, several building sites have been analysed in order to quantify the estimation of CDW generated. Results show that when using plasterboard walls the CDW generation, per m² of built surface can be reduced up to 15.94% compared to the use of traditional brick partitions. In addition, a model describing the accumulation of CDW throughout the project duration is proposed. This model states that CDW mainly accumulates in the middle stages of the project. This study allows an estimation of the amount of CDW to be generated in a building construction site, helping to plan the number and size of containers required at any moment of the construction process, as well as the space required for a proper CDW management.     

A model for estimating construction waste generation index for building project in China

The increasing construction and demolition (C&D) waste causes both cost inefficiency and environmental pollution. Many countries have developed regulations to minimize C&D waste. Implementation of these regulations requires an understanding of the magnitude and material composition of waste stream. Construction waste generation index is a useful tool for estimating the amount of construction waste and can be used as a benchmark to enhance the sustainable performance of construction industry. This paper presents a model for quantifying waste generation per gross floor area (WGA) based on mass balance principle for building construction in China. WGAs for major types of material are estimated using purchased amount of major materials and their material waste rate (MWR). The WGA for minor quantities of materials is estimated together as a percentage of total construction waste. The model is applied to a newly constructed residential building in Shenzhen city of South China. The WGA of this project is 40.7 kg/m², and concrete waste is the largest contributor to the index. Comparisons with transportation records in site, empirical index in China and data in other economies reveal that the proposed model is valid and practical. The proposed model can be used to setup a benchmark WGA for Chinese construction industry by carrying out large-scale investigations in the future.     

Waste Management in Guangdong Cities: The Waste Management Literacy and Waste Reduction Preferences of Domestic Waste Generators

A questionnaire survey was conducted in 2002 on 1365 households in two prefectural-level cities in the Pearl River Delta, Jiangmen and Zhongshan. Three groups of issues are covered in this paper: 1) waste management literacy, concerns, and public participation; 2) waste recycling practices and the potential for waste avoidance; and 3) public environmental literacy. This study confirms findings from previous surveys and provides new information on important issues such as imposing monetary charges on waste and environmental activities, littering, source separation programs (SSPs), and public participation and expectations in local waste management. Saving up recyclable materials for redemption in waste depots is commonly practiced in mainland China regardless of the level of development of a city, although at the household level, high-income families tend to place less value on the revenues to be gained from redemption than lower income groups do. Data from the previous and the present studies indicate that such voluntary but largely economically driven waste recovery behavior diverts at least 10% of the household waste from the waste stream. Although uncompensated SSP is less appealing in the two cities than compensated SSP, it was found that when the median per capita income of a city reaches RMB2000 per month, a high participation rate for uncompensated waste recovery is more likely to occur. Education and income levels are the chief factors affecting littering behavior and the potential for waste avoidance. Contrary to general belief, the local Chinese community is active in microwaste management. The concern, however, is over the inability of the grassroots bureaucracy to deal with rising expectations for waste collection services and neighborhood cleanliness.     

An approach to the acoustic design of outdoor space

This paper focuses on soundscape planning, or acoustic design, in the planning and management of open space in both urban and non‐urban areas. It is based on notions, promoted over several decades, that the acoustic aspects of open space can, and should be, subject to design in the same way as are the visual dimensions. The current paradigm for the management of the outdoor acoustic environment is noise control and soundscape planning needs to adopt quite different practices from noise control with respect to acoustic criteria and measurement. The paper explores the specification of acoustic objectives for outdoor soundscapes and the translation of these objectives into acoustic criteria that are amenable to measurement and prediction as part of the design process. Such objectives, termed Proposed Acoustic Environments, focus on the information content in sounds in a particular space and, only indirectly, on characteristics such as level or loudness. Outdoor acoustic design is mostly concerned with avoiding, or achieving, the masking of one set of information in the acoustic signal with other sets of information in the same signal. These are critical methodological issues if soundscape planning is to move from being a good idea to common practice. The paper sets out the elements of a process for the acoustic design or management of outdoor space.     

中国废弃手机回收的管理策略研究

作为“城市矿产”的典型代表，废弃手机因其废弃数量大、稀贵金属品位高等特性而备受关注，但在推进废弃手机回收过程中存在诸多问题。本文以推动产业发展为立足点，梳理了影响废弃手机回收的两级制衡要素，通过构建GREY-DEMATEL模型，定量评估各要素对废弃手机回收的影响程度并确定优先等级。其中，完善废弃手机回收的管理制度及相应的经济扶持政策成为短期内应着力解决的核心问题，从长期发展来看，废弃手机的前端收集应成为产业关注的重点。基于此，本文立足于废弃手机回收的短期目标及长远发展，分别提出相应的管理策略，为再生资源产业的良性发展提供对策建议。     

Floodplain management: Land acquisition versus preservation of historic buildings in Cambridge,Ontario, Canada

Non-structural adjustments in floodplain management are often avoided because they are seen to infringe on personal rights, adversely affect property values and restrict local tax bases. Land acquisition programs in urban areas encounter a further problem when they lead to demolition of buildings and other structures considered to have historical or architectural value. An experience in Cambridge, Ontario demonstrates that the potential conflict between flood damage reduction and historical preservation objectives can be exacerbated as a result of uncoordinated planning efforts, inflexibility in interpreting mandates, unclear roles for participating agencies, and lack of cooperation Many of these dilemmas can be resolved through consultation and discussion early in the planning process as well as through a willingness to be flexible and to search for a compromise