Research On Compressive And Tensile Strength Of Cemented Sand Gravel Based On Similar Gradation Method

Cemented Sand and Gravel(CSG for short)is a new type of dam body and cofferdam construction material that has appeared in recent years.The cementitious gravel material is mainly made by mixing a small amount of cement and fly ash with crushed stone or pebble.The morphology and mechanical properties of dams constructed from CSG materials are between the traditional RCC dams and modern reinforced concrete dams.The cemented sand gravel dams are borrowing from the RCC dams and reinforced concrete dams A new type of dam body material has been developed under the predominant conditions of both structures.The crushed stone and pebble aggregate of the CSG material are mainly the waste crushed aggregate where the site is located and the pebbles in the nearby river bed area.Unlike other materials,the aggregate used for the gelled sand gravel does not need to be washed and sieved,and can be directly applied after the material is taken,thereby effectively reducing the excavation of the original mine and greatly reducing the construction cost.The CSG construction method is an earth-rock dam construction method,with simple construction machinery,convenient rolling,and fast construction speed,which can effectively shorten the required construction period.In terms of material strength,CSG material has a certain strength to meet the engineering strength requirements because of the cement setting effect of cement.In recent years,in the construction of earthquake prevention and disaster reduction projects,slope protection projects,and dam projects,due to the unique properties of CSG materials with low consumables and low energy consumption,similar CSG materials have received more and more attention.However,CSG cementitious material is in its infancy in China,and there is no uniform industry norm and standard for the material mix ratio and construction method.Therefore,in the process of using CSG materials,the utilization efficiency of their materials still cannot be maximized.In this paper,based on the similar grading theory,the experimental mix design of CSG materials is carried out.The unit cement content of CSG materials,the maximum particle size of aggregates,and the curing age of materials are controlled by variables.The relationship between performance and unit cement content,maximum particle size of aggregate and curing age.The main research contents and innovations of this article are as follows:In this study,based on similar grading theory and design experience of RCC mix ratio,the aggregate gradation of CSG material and the amount of material were used to design a mix test to form a CSG test piece.The test data was analyzed,summarized,and summarized to discuss CSG.The effect of material dosage,aggregate particle gradation and specimen curing specimens on the strength of CSG materials.In this study,by changing the unit cement content of the CSG material,the natural frequency,uniaxial compressive strength,and mass of the specimen were measured before and after the freeze-thaw cycle.The effects of unit cement content,aggregate maximum particle size and curing age of CSG materials under freeze-thaw cycles were investigated,as well as their effects on freeze resistance and uniaxial compressive strength.In this study,a laboratory test was set up to change the unit cement content and the maximum particle size of the test specimen aggregate under the same conditions of water pressure and curing age,and explore the percolation flow of CSG materials and the aggregate particle size and unit cement Based on the relationship of the content,the permeability coefficient of the CSG material is calculated,and the permeability analysis of the CSG material is performed,and study the relationship between impermeability and material strength.This study uses BP artificial neural network system operation to explore the relationship between impact factors and target variables,and derive the importance of each impact factor to the target variable,to provide the best mix ratio design for CSG materials,and for reference in practical engineering.