Research On Carbon Emission Calculation And Emission Reduction Measures Of Prefabricated Building Based On Life-cycle Assessment

In recent decades,human activities have produced a large number of greenhouse gases.Climate warming is becoming more and more obvious,causing a series of problems such as glacier melting,sea level rise and food security.Therefore,reducing greenhouse gas emissions has become the consensus of the international community.Construction energy consumption accounts for 30 %-40 % of global energy consumption,and carbon emissions accounts for about 1/3 of global carbon emissions.In order to achieve energy conservation and emission reduction,the construction industry needs transformation and upgrading.The prefabricated building is an important way for the transformation and upgrading of the construction industry.Due to the advantages of shortening construction period and saving manpower,prefabricated buildings have been vigorously promoted by national and local governments in recent years and have broad application prospects.Therefore,this thesis studies the carbon emissions of prefabricated buildings in the whole life cycle.Firstly,based on the characteristics of prefabricated buildings,this thesis divides the whole life cycle of prefabricated buildings into three stages: materialization stage,operation stage,and demolition stage.And the materialization stage is divided into five stages:material production stage,material transportation stage,prefabricated component production stage,prefabricated component transportation stage and construction stage.Next,the measurement range of carbon emissions in the whole life cycle of prefabricated buildings is defined,and the carbon emission sources at each stage are sorted out.Subsequently,based on the carbon emission factor method,the carbon emission measurement model of the whole life cycle of prefabricated buildings is constructed.Then,taking a prefabricated building in Guangzhou as an engineering example.The carbon emissions of the whole life cycle of the building,and the carbon emissions of the three typical apartment layouts of the building in the materialization stage and operation stage are calculated.And the carbon emissions of the building and different apartment layouts are analyzed.Finally,based on the previous research,relevant emission reduction suggestions are put forward.The results show that :（1）For the building,the operation stage has the most carbon emissions,followed by the materialization stage,and finally the demolition stage.Among the materialization stage,the materials production stage has the highest carbon emission,followed by the construction stage and the materials transportation stage,and finally the prefabricated component production stage and the prefabricated component transportation stage.（2）For apartment layouts,the carbon emission per unit floor area of the apartment layout has a negative correlation with the size of the floor area of the apartment layout.The larger the unit floor area of the apartment layout,the smaller the carbon emission per unit floor of the apartment layout.There is a positive correlation between the size of the total carbon emission of a apartment layout and the size of the floor area of the apartment layout.The larger the floor area of the apartment layout,the greater the total carbon emission of the apartment layout.