Study On The Comprehensive Index Of Assembled Concrete Structure System Of Sea Sand In Coastal Area ——An Example Of Assembled Farmhouse

At present,there are serious problems of environmental damage and lack of durability in China’s traditional coastal area farmhouse structures:（1）in coastal areas,reinforced concrete structures have a high risk of steel corrosion,which seriously reduces the service life of engineering structures;（2）traditional cement-based concrete materials have high carbon emissions in both the production and fabrication processes;（3）the application of sea sand can solve the traditional native river sand resources（3）the application of marine sand can solve the problems of scarcity of traditional virgin river sand resources and severe environmental damage caused by over-exploitation.In response to the above problems,the author’s team has carried out research in recent years on "green toughness" assembly-type farmhouse construction system and equipment key technology research and development,and proposed a kind of sea sand concrete assembly-type farmhouse.At present,the construction of the coastal farmhouse project needs to meet the technical,economic and environmental needs of various aspects,so how to obtain the indicators of this sea-sand concrete assembled farmhouse,based on this to establish a comprehensive evaluation index system to analyse and compare the overall advantages and disadvantages of this system and the traditional structural system,corresponding to the application of this new material and structural system to promote and optimise is of great importance.Based on the analysis of literature and field research,this thesis analyses and explains the basic characteristics and functions of the studied sea-sand concrete buildings and assembled farmhouses,and introduces the evaluation methods such as hierarchical analysis and the Delphi method.Next,the literature and research data are analysed to carry out the analysis of the technical and economic indicators of the sea sand concrete assembled farmhouses.Then,a hierarchical structure model is established to clarify the three-tier analysis structure of target,criterion and indicator layers.Through literature review and field research,26 indicators were initially identified in terms of technology,economy and environment.Then,combining the actual situation of the rural areas in the coastal region and the questionnaire survey data,the similar indicators were combined and the unimportant ones were removed to finally determine 18 main indicators,and the evaluation index system was initially established.Based on the process of hierarchical analysis,the judgment matrix was obtained through the questionnaire,and the index weights were calculated through the establishment of a mathematical model to finally establish a comprehensive evaluation index system of sea sand concrete assembled farmhouse.This comprehensive evaluation index system was then applied to the sea-sand concrete assembled farmhouse project,using analytical data and on-site research to determine the scores of each evaluation index,and calculating the total score based on the index weights to compare the comprehensive evaluation of the three construction modes: traditional cast-in-place reinforced concrete,reinforced concrete assembled and sea-sand concrete assembled;finally,the evaluation results were analysed to conclude that cost and construction technology are Finally,the evaluation results are analysed to conclude that cost and construction technology are the main factors in the application and promotion of sea-sand concrete assembled farmhouses,and corresponding development suggestions are put forward.This thesis explores the construction of a comprehensive evaluation index system for sea-sand concrete assembled farmhouses,and gives preliminary comparison and evaluation results,finding that the constraints to the practical application of sea-sand concrete assembled farmhouses are their construction and use costs;concluding that sea-sand concrete assembled farmhouses can be used in coastal areas where river sand resources are depleted,labour costs are relatively high and reinforced concrete structures are susceptible to corrosion.The project provides an important theoretical reference and data base for the development and promotion of new concrete materials for the construction of assembled farmhouses.