Sustainablility Evaluation Of Prefabricated And Construction Stages Of Assembled Buildings Based On SNA

The Social Life Cycle Assessment(S-LCA)is a tool for social impact assessment of products in the world.However,the development is not mature.Life Cycle Assessment(LCA)is a relatively mature tool for life cycle environmental impact assessment of products.S-LCA is a complement to the social dimension of LCA,and the two are closely linked.In recent years,the assembled building has been promoted by the government for their high production efficiency,energy saving and environmental protection,and researches on assembled buildings have become a hot spot.However,the current researches on the sustainable evaluation of assembled buildings are mainly concentrated in the environmental and economic fields.There are less research on the social impact assessment of assembled buildings.Currently,researches on the sustainable comprehensive evaluation of assembled buildings based on the theory of social life cycle impact assessment and environmental life cycle impact assessment have not been carried out.Therefore,in order to make up for the shortcomings in the field of sustainable evaluation of assembled buildings and promote the better development of assembled buildings,this paper evaluates the sustainability of prefabricated and constructed stages of the assembled building from three perspectives:social,environmental,and integrated social and environmental impacts.The main work includes the following aspects:(1)Based on the S-LCA technical framework and Social Network Analysis(SNA)theory,the social impact assessment model of assembled buildings in construction and construction stages was established.Applying the established social impact assessment model to specific case,the result shows that the prefabrication stage of the assembled building has better social impact than the construction phase.Further analysis of the social impact results of various stakeholders and sub-categories in the evaluation model revealed the negative social influences of the assembled buildings.(2)Based on the LCA method from the cradle to the gate,the environmental impact of the prefabrication and construction phases in the case project was calculated.The result shows that as the production activities are transferred to the component plant,the environmental impact of the prefabrication phase is greater than that of the construction phase.Whether it is the prefabrication phase or the construction phase,the resource and energy consumption account for the largest proportion of the environmental impact.(3)Two visual social networks have been established for subcategories of the social impact and three endpoint indicators of environmental impact.Through the analysis of the individual network of the social impact network,the weight of every social influence factor in the social impact assessment model is determined and the key influencing factors in the social impact assessment of the prefabrication and construction phases are identified.Through individual network analysis of the environmental impact network,it is found that the three endpoint indicators have the same importance to the environmental impact.(4)Based on the multi-criteria decision-making method and the life cycle sustainable evaluation theory,a comprehensive comparison model of social and environmental impacts in the prefabrication and construction stages of assembled buildings was established,and the model was applied to the case.The results showed that considereing both social and environmental aspects,the sustainability of the prefabricated stage of the assembled building is still better than the construction phase.