Study On Impermeability Of Structural Self-Waterproof Recycled Concrete

In recent years,with the rapid development of underground construction and the increasing number of underground engineering projects in China,the waterproof requirements for underground structure engineering are also improving continuously,the problem of construction waste produced by large-scale urban construction is gradually becoming more prominent.Therefore,this paper conducts research on the impermeability of self-waterproof recycled concrete based on the above two aspects.One the one hand,this study alleviates the problem of structural leakage caused by cracking and deformation of the concrete structure itself due to various effects.On the other hand,it also provides new ideas for the use of waste concrete and reduces the exploitation of natural resources as response to the government’s call to protect the environment.The main work of this paper includes:(1)Obtained the water absorption,water content,apparent density,bulk density,slump,compressive strength and tensile strength of waste concrete in self-waterproof recycled concrete through tests and gave the changes of compressive strength,tensile strength and slump of selfwaterproof recycled concrete with the content of waste concrete and YYK water-repellent change law;Used SPSS software to perform multiple linear regression analysis,and gave the regression equation of the slump,compressive strength and tensile strength of self-waterproof recycled concrete;(2)Carried out impermeability tests of self-waterproof recycled concrete under different dosages of waste concrete and YYK waterproofing agent by the water penetration height method,obtained the changes of permeability coefficient under different conditions.Ran multiple regression analysis using SPSS software and gave the regression equation of permeability coefficient with respect to the two factors.Obtained the change law and fitting curve of the impermeability coefficient of self-waterproof recycled concrete with respect to the amount of waste concrete and the amount of YYK waterproofing agent according to the results of range and variance analysis;(3)Conducted impermeability tests of self-waterproof recycled concrete under freeze-thaw cycle conditions,and obtained the permeability coefficient of self-waterproof recycled concrete with the amount of waste concrete and YYK waterproofing agent.(4)Compared and analyzed the microstructure of self-waterproof recycled concrete specimens by using scanning electron microscope and energy spectrum analysis.Obtained the microstructure characteristics and influence mechanism of self-waterproof recycled concrete under the influence of different waste concrete and YYK water repellent content.Compared and analyzed the influence of presence of additives and the number of freeze-thaw cycles on the impermeability of selfwaterproof recycled concrete under the action of freeze-thaw cycle;(5)Conducted a detailed study of the second phase of a concrete construction project in Xinwu district,Wuxi city,Jiangsu province.Discussed the mechanical properties,impermeability and microscopic influence of the self-waterproof recycled concrete used in the project,gave the optimal dosage of waste concrete and YYK waterproofing agent in the project,and put forward reasonable suggestions for actual project requirements.