Green Benefit Evaluation And Compratative Studies Of Prefabricated Concrete Buildings And Traditional Buildings

Driven by policies,prefabricated buildings are becoming more and more widespread,and it is one of the means to achieve sustainable development of the construction industry.However,in practice,it encountered problems such as high cost and unobvious environmental benefits,which also caused controversy in the society about the promotion of fabricated buildings.Studying the green benefits of prefabricated buildings can help deepen understanding and reduce differences in the promotion process.The purpose of this paper is to establish green benefit evaluation system,evaluate the green benefits of prefabricated concrete buildings,and take a comparative analysis with traditional buildings,which provide suggestions for the popularization and application of prefabricated concrete buildings.The term "green benefits" refers to the resource conservation and environmental protection effects of the building during the materialization phase.This paper has selected 18 evaluation indexes on the basis of inventory analysis,and sort out these indexes from two types——resource depletion and environmental load according to the connotation of green benefits.In order to reflect the scarcity of resources,based on the resource depletion potential factor,a weighted evaluation of 12 index of resource depletion is conducted,and a resource depletion index(RDI)calculation model is established.In order to reflect the current emphasis of Chinese environmental governance,based on the distance-to-target method,6 indexs of environmental load are weighted and an environmental load index(ELI)calculation model is established.Green benefit of prefabricated concrete building indicated by the RDI and ELI.Finally,prefabricated building and a cast-in-suit building are selected as empirical cases,which have the similar scales,and the data of building material consumption and energy consumption were collected in the process of commercial concrete mixing,prefabricated component production,material transportation,and on-site installation.The study found that the resource depletion potential factors of crude oil,manganese ore and fluorite are large,and they have a greater weight in resource depletion indicators.The evaluation results show that the resource depletion of prefabricated concrete buildings is reduced by 8.2% and the environmental load is reduced by 5.5% compared to cast-in-situ concrete buildings.In terms of resource depletion,the advantage of prefabricated concrete buildings is their low crude oil depletion potential.The advantage of prefabricated buildings in environmental load is that their environmental impact of various emissions is less than that of cast-in-situ buildings.By analyzing the input-output list of prefabricated building during materialization stages,it was found that steel and commercial concrete are important factors affecting green benefits.Through sensitivity analysis,it is found that increasing the prefabrication rate can reduce resource loss but increased environmental load.Based on the research results in this paper,it is suggested that a moderate increase in the prefabrication rate and the slab overlap rate,optimizing the design,reduce transportation distance,seeking green materials to replace steel bars and concrete will help improve the green benefits of fabricated concrete buildings.