Research On Construction And Demolition Waste Quantification And Management Strategies

Since the implementation of the reform and opening policy, the constructionindustry in China has undergone a blooming development. Countless construction,renovation and demolition activities can be found everywhere because of the rapidurbanization, which also caused a marvelous amount of construction and demolitionwaste (CDW). If dealt with unappreciated approaches, the stream of this waste will leadhorrible environmental problems to the soil, waste and atmosphere. However, aneffective and efficient waste management could not only reuse or recycle the wastedmaterials, but also reduce CDW generation at sources. Moreover, accuratequantification is an essential and key procedure for achieving promising wastemanagement. The CDW quantification on a regional level could supply the governmentdecision-makers valuable information of waste generation trend, supporting them tomake related monitoring policies. And the CDW quantification on a project level couldgive profound information to contractors about material usage and wastage level,assisting them to conduct more effective project management. Therefore, it is veryessential to study the quantification methodologies of CDW.In this thesis, basic definitions of CDW and generating reasons throughout theproject lifecycle are firstly presented. The current situation of CDW disposal in themainland and Hong Kong is described, and a hierarchy model for CDW management isproposed. Then, through a comprehensive and through literature review, the CDWquantification methodologies are categorized into six kinds on regional and projectlevels. They are per capita multiplier method, site visit method, generation-rate-per-unitcalculation, material flow analysis, system modeling approach and other specialmethods for particular materials. Establishing such an index system would be a valuablereference for CDW quantification on different levels.In the background of abundant amount of CDW generation and limited capacitiesof landfills, it is important and necessary to predict CDW generation on a regional level.To solve this problem, the methodology of gene expression programming (GEP) isintroduced, and the procedures of GEP modeling are demonstrated for developing a newquantification methodology on a regional level. Because Hong Kong has more detailed data, Hong Kong is selected as a research object in this thesis, explaining how to applyGEP to forecast future CDW generation on a regional level. Through the comparison ofraining data and validation data, the effectiveness of this model is verified, and theCDW generation in future two years is forecasted. The modeling results show thatCDW amounts generated in future two years are13159560ton and12601840tonrespectively.However, it is not sufficient to realize the objective of CDW reduction only byquantification; more effective management strategies are needed to achieve this aim.Through comprehensive literature review, strategies for effective waste management onboth macro and micro levels are proposed. On a macro level, the management strategiesinclude improving CDW management regulations, implementing CDW chargingscheme, establishing incentive mechanism and strengthening publicity efforts. On amicro level, the CDW management strategies involve application of prefabrication,establishment of bar-code system, implementing of selective demolition and conductingof on-site sorting. These management strategies are all selected from literature, and havealready been proved to be effective.