| In the course of engineering construction,sand and stone,as an important part of concrete structure material,its quality has an important influence on the quality and durability of the whole project.In recent years,with the construction of a large number of projects such as traffic,the supply and demand of river sand is becoming more and more inadequate.In addition,the environmental protection concept is increasing day by day,the protection of river sand is becoming more and more strict,and the use of manufactured sand has become an inevitable trend.Manufactured sand is a kind of artificial sand-stone material obtained by sand making machine and other professional sand-making equipment Compared with natural river sand,its grain surface is rough,needle shape is more,edge angle is sharp,water absorption is high,gradation is poor,and contains a certain amount of stone powder.Therefore,the preparation technology and properties of manufactured sand concrete are quite different from that of natural sand concrete.In this paper,based on the compounding and performance testing of manufactured sand corrosion-proof concrete,the mechanical properties of manufactured sand and river sand in different structures of highway bridges(cast-in-place pile,pier cap,beam body)are compared and studied.Volume stability and durability,combined with solid structure testing technology,were used to test and study the beam C50 sand concrete.The test results show that:The test results show that:1.The manufactured sand concrete with different structures facing the bridge can be prepared by using granite sand.Compared with river sand concrete,the properties of granite sand concrete are as follows:(1)Mechanical properties:cast-in-place pile,The compressive strength of mound cap concrete is slightly higher than that of river sand concrete,while the compressive strength of beam C50 manufactured sand concrete is slightly lower than that of river sand concrete.Due to the angular property of the manufactured sand,sand,the flexural strength of the manufactured sand concrete is higher than that of the river sand concrete,and the elastic modulus is the same as that of the river sand concrete.(2)Volume stability:three kinds of strength grade manufactured sand concrete plastic shrinkage deformation,Drying shrinkage deformation and autogenous shrinkage deformation The creep degree and coefficient of creep of 7-day-old concrete and 10-day-old concrete are lower than that of river sand concrete.(3)Durability:resistance to chloride ion penetration and frost resistance are better than natural river sand concrete.2.The manufactured sand prepared by using the thunder-stone tunnel slag as the raw material can prepare the C50-manufactured sand anti-corrosion concrete which meets the requirements of the construction performance of the on-site prefabricated beam,the mechanical property meets the specification and the design requirements,and the appearance quality of the manufactured sand concrete precast beam is good,there is no significant difference between the precast beams of natural river sand concrete.The mechanical property index and the non-destructive testing index of the solid structure are better than that of the precast beam with the river sand concrete in the field,ad the application of the granite manufactured sand concrete in the bridge high-grade prestressed beam is realized. |
