Experimental Study On The Performance Of 3D Printed Concrete For Assembled Ecological River Retaining Wal

The organic combination of 3D printing integration technology and prefabricated building construction technology is a novel construction and construction method,which has the advantages of intelligent construction,shortening the construction period and reducing construction pollution.Starting from the integration technology of 3D printing,this paper studies the influence of single factor dosage on the working performance and mechanical properties of 3D printing concrete,and its changing rule.Through orthogonal tests of different factors,the optimal proportion of 3D printing concrete suitable for this project is obtained,and the optimal working performance and mechanical properties are determined.According to the actual engineering environment,control the single dosage of materials,study the change law of impermeability and frost resistance of 3D printed concrete components,and compare and analyze their durability;The structural design and construction technology of prefabricated structure are expounded.The emergence of new construction methods and new technologies not only brings new research ideas,but also presents new challenges.In view of the above,this thesis makes a detailed experimental research and analysis on the performance of 3D printed concrete,and describes the construction technology of prefabricated buildings.The main research contents and results of this thesis are as follows:1.New technology and construction methods put forward requirements for the selection of materials.According to the characteristics of different materials of 3D printed concrete,the mix proportion of foundation was optimized.According to the requirements of mechanical properties and working performance of 3D printed concrete materials,the effects of sand ratio,fiber length,water-binder ratio,sand-binder ratio and mineral powder content on the properties of the materials were analyzed through the tests of fluidity,slump,setting time,compressive strength and flexural strength.2.Five factors,including sand ratio,water-binder ratio,cement-sand ratio,mineral powder content and fiber content,are set as variables in the experimental study.By controlling the single content of materials,the changing trend and optimal interval of the working performance and mechanical properties of the mixture ratio are studied.Under the same ratio,controlling the different content of single materials,it is concluded that the water-binder ratio and fiber content have the most significant influence on the fluidity of 3D printed concrete,the water-binder ratio has the most significant influence on the compressive strength of 3D printed concrete,and the fiber content has the greatest influence on 3D printed concrete.Through orthogonal experimental study,the optimum content of four experimental factors,namely sand ratio,water-binder ratio,mineral powder content and fiber content,is obtained,namely,sand ratio is 0.50,water-binder ratio is 0.40,mineral powder content is 0.30% and fiber content is1.5%.Under the optimum ratio,the 28-day compressive strength and flexural strength are68.2MPa and 9.3MPa respectively.3.In view of the practical application of 3D in the actual engineering environment,whether the emerging technology is applicable in the specific environment and whether the printed and poured products meet the specific environment,the experimental comparison and durability analysis of the poured products are made.Under the same proportion,the change of single dosage is studied by controlling the sand ratio,water-binder ratio,mineral powder dosage and fiber dosage,and the change law of impermeability of 3D printed concrete under single dosage is studied.According to the change law,the influence on impermeability of 3D printed concrete is explored.Through the single mixing experiment,it is found that the order of the influence of sand ratio,water-binder ratio,mineral powder content and fiber content on impermeability of 3D printed concrete is sand ratio > water-binder ratio > mineral powder content > fiber content.When sand ratio is 0.50,water-binder ratio is 0.40,mineral powder content is 0.30% and fiber content is 1.5%,the impermeability of 3D printed concrete is the best.The order of influence of water-binder ratio,mineral powder content and fiber content on impermeability of 3D printed concrete is sand ratio > water-binder ratio > mineral powder content > fiber content.When sand ratio is 0.50,water-binder ratio is 0.40,mineral powder content is 0.30% and fiber content is 1.5%,the frost resistance of 3D printed concrete is the best.4.3D printing prefabricated technology is different from the traditional structure,construction and construction system,and the structural system,assembly characteristics and construction process of the new technology are studied and discussed.