Research On Carbon Emission Based On The Bill Of Quantity In Materialization Stage Of Prefabricated Building

The greenhouse effect caused by excessive emission of greenhouse gases has become the focus of the international community,it needs to be solved urgently.Buildings consume 40% of the world's energy and cause 36% carbom emission,Second only to industrial energy.Consumption.traditional energy-intensive construction methods are in urgent need of improvement.In recent years,prefabricated buildings with energy saving and emission reduction have attracted people's attention.Reinforced concrete buildings are large in quantity and wide in scope.However,the quantitative research on carbon emission in the physical and chemical stage of prefabricated buildings is insufficient,and there is no scientific carbon emission measurement system.Based on the analysis of domestic and foreign research on carbon emissions and prefabricated buildings,this paper takes prefabricated concrete buildings as the research object to calculate and study the carbon emissions in materialization stages of prefabricated buildings and calculate the carbon emissions in each materialization stage of prefabricated buildings.The main conclusions are as follows:(1)The carbon emission measurement of traditional buildings is sorted out.Due to the operation of each participant,the accuracy of carbon emission measurement is affected by the difficulty of data acquisition in traditional buildings.The inability to predict carbon emissions at the design stage leads to poor operability.There is no uniform calculation standard for carbon emission,and the complex calculation process leads to poor universality.(2)The formulae for calculating carbon emission at each materialization stage were constructed.Basis on the carbon emission measurement model of the traditional construction method,combined with the characteristics of prefab building,the materialization stages of prefab building are divided into production of building materials,transportation of building materials,production of components,transportation of components and on-site construction.(3)A carbon emission measurement system for prefabricated buildings based on bill of quantities was established.The system contains two key systems: carbon emission factor library and bill of quantities.Carbon emission factors were obtained by consulting the literature.The bill of quantities is modeled by BIM calculation software and converted into the bill of quantities derived by BIM in combination with the engineering consumption quota.(4)Taking a prefabricated building in Zhuhai city as an example,each materialization stages and its total carbon emissions are calculated.The results show that the carbon emission of prefabricated buildings mainly comes from the production of building materials(90.76%)and the on-site construction(6.68%).(5)Put forward the carbon emission reduction strategy for each phase of physical and chemical prefabricated building.In the production stage of building materials,low carbon materials are selected to improve the building recovery rate.Eliminate the old equipment in the component production stage,strengthen the site management and save the building materials.Reduce the transportation load,optimizethe transportation plan,shorten the transportation distance and use energy saving transportation vehicles to reduce the carbon emission during transportation.In the field construction stage,low energy consumption machinery,technology,scientific management,application of BIM+ block chain technology,etc.are selected to reduce carbon emissions.The bill of quantities constructed in this paper constructs a carbon emission measurement system for prefabricated buildings in the physical and chemical stages,which makes the quantitative calculation of carbon emissions advance to the pre-construction period,which is helpful for the carbon emission control and management of prefabricated buildings and has important practical significance.The research results not only provide scientific basis for quantifying carbon emissions of prefabricated buildings,but also provide practical reference for future carbon emissions trading.