Presentation on theme: "Construction Waste Minimisation Design in China: 中国建筑垃圾最小化设计 : through a Comparative study between the UK and China Yi Ying HAO, Jian Kang School of Architecture,"— Presentation transcript:
Construction Waste Minimisation Design in China: 中国建筑垃圾最小化设计 : through a Comparative study between the UK and China Yi Ying HAO, Jian Kang School of Architecture, University of Sheffield
Introduction The UK and China are both confronted with an increasing rate of construction （建设速度） and a decreasing capacity of landfill （填埋能力） at present, which calls for construction waste minimisation urgently. Considerable differences have been found in the effort on waste minimisation （垃圾最小化） as well as on construction waste minimisation design （建筑垃圾最小化设计） between the UK and China. A comparative study was made based on the existing survey in the UK. The survey in China includes: Acquaintance of the legislations ( 对法律的熟悉程度 ) Implementation of construction waste minimisation design ( 建 筑垃圾最小化设计实施 ) Causes of construction waste ( 建筑垃圾产生原因 ) Barriers & incentives for construction waste minimisation design ( 建筑垃圾最小化设计的障碍和鼓励措施 ) Architects’ attitudes to construction waste ( 建筑师对建筑垃圾 的态度 ) Source: http://photos.nphoto.net/photos/2007- 09/06/ff80808114c5908e0114d6acb3cd5432.shtml
Introduction UKChina Construction waste ( 建筑垃圾 ) 120 million t of construction, demolition and excavation waste is produced by construction industry per annum. More than 25 million t of construction waste is disposed by landfill in the UK every year. By 2020, China will increase 30 billion m 2 of construction area, so the amount of potential construction waste will be an amazing number (1500-1800 million t). Need for reclaimed and recycled materials ( 对回收再利 用的材料的需求 ) (1)Minimisation of wastes during aggregates production (2)Careful use of aggregates in the process of construction, (3)Appropriate use of aggregates (4)Increased substitution of secondary and recycled materials for primary aggregates. Green Construction Guideline (2007) ( 绿色施工 导则 )encourages the development of new technology, new equipment and new materials in green construction, including the application technology of reclamation of the construction waste in envelop materials. Information sources for construction waste minimisation design ( 建筑垃圾最小 化设计的信息来源 ) Legislations on waste disposal Handbooks on construction waste minimization Website, competition, training course for waste minimization design Legislations on waste disposal Information of material recycling little information supports online Models for construction waste evaluation ( 建筑垃圾 评估模型 ) BREEAM, SPeAR, LCA In 2007, Green Building Assessment ( 绿色建筑 评估 ) the first book in China systematically is published introducing the U.S. LEED, U.K. BREEAM, Japan CASBEE, GreenCalc+, Taiwan Green Building, Australian NABERS. Role of construction waste minimisation design ( 建筑垃圾最小 化设计的作用 ) Design for Reuse and Recovery; Design for Off Site Construction; Design for Materials Optimisation; Design for Waste Efficient Procurement; and Design for Deconstruction and Flexibility. when it comes to construction waste minimisation, waste management and technology supports seem to be emphasized most frequently. The views on designing out waste are limited.
Method Respondents The architects in Grade A Architecture Design Institutes in provincial capitals ( 省会城市的甲级设计院 ) The ranking of these institutions in China is mainly based on the registered capital, the scale of projects and the number of registered architects. Questions The questionnaire totally includes 20 questions, with seven same questions as those of the survey in the UK. Single-choice questions, multiple-choice questions, rating scales and open questions in the questionnaire. Questionnaire distribution and return The use of questionnaire web page The address of the web page was sent to 80 architects, with the response rate of 76%. Data Analysis Statistical Package for Social Science (SPSS) Approaches of analyzing: One Sampling t-Test (comparing means) Independent samples t- Test (compare variables between two group) Tabulated open-ended questions (collect and analyze individual suggestions)
Method Working age （工作年限） Education level （教育程度） Workload （工作量）
RESULTS: Chinese architects Acquaintance with relevant legislations ( 对相关法律的了解程度 ) The respondents do not know the legislations. 《中华人民共 和国固体废物污染环境防治法》 34.4% 《城市固体垃圾处理法》 37.7% 《绿色施工导则》 39% 《城市建筑垃圾管理 规定》 37.7% Acquaintances of the concept of construction waste minimisation design ( 对建筑垃圾最小化设计概念的了解程度 ) Over 60% of respondents reported that they never heard the concept of construction waste minimisation by design, therefore, most of them have not had a clear and scientific idea on what is construction waste minimisation by design. Courses and projects relevant to construction waste minimisation design in college ( 大学里和建筑垃圾最小化相关的课 程和设计 ) More than 85% said that they never attended any courses on designing out waste. Meanwhile, nearly 80% acknowledged that they never did the projects which were concerned with construction waste minimisation design in college. Background Information
Green Housing Rating Systems The usage of Green Housing Rating Systems ( 绿色建筑评估系统 ) can reflect the Chinese architects’ concern with sustainable design and construction waste minimisation. Never over 60% A little nearly 20% Often 6.6%. Employ Green Housing Rating Systems in projects RESULTS: Chinese architects
Importance of construction waste minimisation design Very important over 35% Extremely important about 22% Not important at all 0% Most of the Chinese architects acknowledge the importance of designing out waste. RESULTS: Chinese architects
Views on the importance of construction waste minimisation design ‘extremely important’ and ‘very important’ (1) Beneficial to saving sources ( 资源 )and energy ( 能源 ) (2) Reducing waste ( 垃圾 )and pollution ( 污染 )and protecting environment. (3) Considered as a challenge ( 挑战 )as well as a responsibility ( 责任 ) (4) The problem of waste would be more serious in the foreseeable future ‘moderately important’ (1) The current economic and management level ( 经济和管理 水平 )could not support it. (2) No requirement from clients ( 甲方 )and legislation( 法律 ), (3) Little knowledge ( 了解 )of it (4) A lack of design time ( 设计时间 ). ‘slightly important’ (1) Mainly produced during the process of construction( 建造过 程 ), and not related to design strategies( 设计策略 ) (2) Inevitable due to big design changes (3) Considered as a stunt ( 噱头 ) (4) Complicated and difficult to put into practice, while less benefit (5)The public have not pay attention to it. ( 公众不重视 ) “ 尽管好多建成建筑，会因 为设计不当，施工不当等 等出现很多问题，但只要 是满足审核，不影响销售， 都会原封不动的接受。 ” “ 说实话，觉得设计改动巨 大，导致最后错误的信息 巨多，无可避免。 ” RESULTS: Chinese architects “ 当建筑接近环境的承载量， 建筑垃圾和环境之间的关 系会变的极其敏感，所以 在大量问题没出现之前， 研究和用于实践，避免严 重后果的出现时十分重要 的。 ”
Information sources for waste minimisation More than 50% of information of waste minimisation came from media and articles ( 媒体 / 文章 ), but the information support from training courses ( 培训课 程 ) and professional bodies was very limited, each occupying 3.3%. The architects in the UK had more information channels, including professional bodies ( 专业团体 ), personal research ( 个人研究 ). The fact that the information sources are relatively inadequate （不足的） can reflect the current situation that the consciousness of the importance of information for designing out waste （垃圾最小化设计信息的重要性） is still not enough in the whole society of China. RESULTS: comparison between the UK and China: what is the problem? UK (Source: Osmani & Glass, 2007)China
Waste minimisation design barriers ‘Lack of interest from clients’ ( 甲方缺少兴趣 )is also the top significant waste minimisation barrier in China, followed by ‘poorly defined individual responsibility’ ( 不明确的个人职责 )and ‘lack of training’( 缺少培训 ). (b) China Barriers (China) Responses Mean rating Ranking Lack of interest from clients4.121 Poorly defined individual responsibilities3.762 Lack of training3.753 Waste accepted as inevitable3.594 1. Not a barrier; 2. Insignificant barrier; 3. Minor barrier; 4. Significant barrier; 5. Major barrier. (a) UK (Source: Osmani & Glass, 2007) Barriers (UK) Responses Mean rating Ranking Lack of interest from clients3.881 Waste accepted as inevitable3.832 Poorly defined individual responsibilities3.803 Lack of training3.704 Nearly 70% said that clients never called for waste minimisation design, while only 3.3% declared clients often asked for it. RESULTS: comparison between the UK and China: what is the problem?
Causes of construction waste Design stages Site operations Last minute change due to the clients’ requirement ( 甲方要求导致的最后的改动 ) 4.15 Design changes ( 设计改动 ) 3.93 Detailing errors ( 细节错误 ) 3.66 The difference between these mean ratings of the listed causes is slight. The mean ratings are relatively high. Off-cut from cutting materials ( 切割材料带来的下脚料 ) 4.31 Unused materials and products ( 未使用的材料和产品 ) 4.28 waste from application processes ( 实施过程中产生的垃圾 ) 4.10 The mean ratings of each cause of waste during site operations are relatively higher than that during design stages, the same as the results from the architects in the UK. RESULTS: comparison between the UK and China: what is the problem?
Waste minimisation design incentives Chinese architects also believed legislation ( 法律法规 ) was the key waste minimisation incentive, followed by financial rewards, while training ( 培训 ) was the least significant measure. An allowance ( 补助 ) for recycled construction products ( 再生建筑产品 ), Tax credit ( 抵免所得税 ) for the construction companies use recycled products ( 使用再生产品 ), a higher tax ( 较高税收 ) on the construction companies use original products ( 使用原始产品 ) to encourage reducing( 减少 ), reusing ( 再利用 ) and recycling ( 循环使用 ) of waste materials. China Incentives (China)Responses Mean rating Ranking Legislation4.401 Financial rewards4.302 Waste management policy in place3.743 Training3.354 1. Not an incentive; 2. Insignificant incentive; 3. Minor incentive; 4. Significant incentive; 5. Major incentive. UK (Source: Osmani & Glass, 2007) Incentives (UK) Responses Mean rating Ranking Legislation4.551 Financial rewards4.551 Waste management policy in place3.932 Training3.903 RESULTS: comparison between the UK and China: what can we do?
Waste minimisation design strategies Generally the waste minimisation design strategies are not very often used in projects in China. The difference between two countries are not significant. F & D ( 垃圾测算可行性研究 )&( 可拆解设 计 )strategies are the least popular in projects in China, which is the same as in the UK. China Waste minimisation design strategies (China) Architects responses PercentageMean ratingRanking 12345 Feasibility study of waste estimation 50.827.911.59.801.808 Designing for deconstruction 36.127.9 8.202.087 Use of standard dimensions and units 14.8126.96.36.199.83.031 Use of prefabricated units 16.419.739.3188.8.131.524 Specifying reclaimed/recycled materials 16.442.6184.108.40.206.435 Use of standard materials to avoid Cutting 14.816.439.3220.127.116.112 Avoidance of late variations in design 19.7 31.223.06.62.783 Guidance for hazardous waste Management 32.8 18.011.54.92.236 1. Never been used; 2. Rarely used; 3. Used in some projects; 4. Used in most projects; 5. Used in all project. RESULTS: comparison between the UK and China ： what can we do?
Waste minimisation design ‘Old building reconstruction’ ( 旧建筑 改造 )is the most usual in practical projects, and it is considered as the most effective construction cost-saving method. The ‘use of recycled materials’( 使用再生材料 ) is rarely put in practice ， but it is considered as the second effective method. design types(China)Responses Mean ratingRanking Old building reconstruction2.501 Flexible design2.102 Reclamation of construction materials2.073 Use of recycled materials (e.g. recycled concrete & recycled bricks) 2.024 1. Never been used; 2.Rarely used ; 3.Used in some projects; 4.Used in most projects; 5.Used in all projects. Design types(China)Responses Mean ratingRanking Old building reconstruction3.371 Use of recycled materials (e.g. recycled concrete & recycled bricks) 3.292 Flexible design3.203 Reclamation of construction materials2.674 1. Not at all; 2.Slightly; 3.Moderately; 4.Very; 5.Extremely. Cost-saving of construction waste minimisation design Implementation of construction waste minimisation design RESULTS: comparison between the UK and China ： what can we do?
Waste minimisation management means In China, more than 60% of respondents acknowledged that they never did anything in waste minimisation management means. The respondents who never did anything for these responsibilities in China were twice ( 两倍 )that in the UK. The architects in the UK have more means in construction waste minimisation. RESULTS: comparison between the UK and China ： what can we do?