Experimental Study On The Mechanics And Sulfate Erosion Resistance Of Silica Fume/basalt-polypropylene Hybrid Fiber Concrete

Concrete is a material often used in civil engineering construction,and it is the most important building material in the world.It is widely used in civil and military buildings.As a brittle material,concrete has the disadvantages of low tensile strength and weak crack resistance.Adding fibers to concrete can effectively improve split tensile and flexural strength and increase toughness.Because of the filling effect and pozzolan effect of silica fume,mixing silica fume in concrete can significantly improve the mechanical properties and resistance to sulfate attack of concrete.In this test,silica fume,basalt fiber and polypropylene fiber were used as concrete reinforcement.First,the effect of single-doped silicon powder and single-doped fiber on the mechanical properties of concrete was studied.Then combined with the optimal amount of silica fume,the mechanical properties of silica fume / basalt-polypropylene hybrid fiber concrete with different mixing ratios were studied.Finally,by testing the quality corrosion coefficient and strength corrosion coefficient of single-doped silica fume concrete,single-doped basalt concrete,single-doped polypropylene concrete and silica fume /basalt-polypropylene mixed fiber concrete,the single-doped silica fume,single-doped basalt fiber,Effect of single-doped polypropylene fiber and three-doped polypropylene fiber on resistance to sulfate attack of concrete.conclusion as below:(1)The mechanical properties of 4%,6%,8%,10%,and 12% silica-concrete concrete were tested.From the data,it can be known that when the silicon powder content is 8%,the compressive strength,axial compressive strength,split tensile strength and flexural strength are all maximum values;the content is analyzed as 0.05%,0.10%,0.15%,Basalt fiber-reinforced concrete with 0.20% and 0.25%,the cubic compressive strength is the highest when the fiber content is 0.15%,and the split tensile and flexural strength are the maximum when the fiber content is 0.20%;For 0.30%,0.40%,and 0.50% polypropylene fiber concrete,when the fiber content is 0.30%,the compressive strength is the largest,and when the fiber content is 0.50%,the split tensile and flexural strength are the maximum.(2)Through compressive,split tensile,and flexural strength tests,the effects of different fiber content on the basic mechanical properties of silica fume / basalt-polypropylene hybrid fiber concrete at the optimal silica fume content were studied.As an example,when the content of silicon powder is 8%,the content of basalt fiber is 0.05%,and the content of polypropylene fiber is 0.50%,the compressive strength of concrete is the largest,which is73.68 MPa.When the content of silicon powder is 8%,basalt fiber When the blending amount is 0.15% and the polypropylene fiber blending amount is 0.50%,the concrete's split tensile and flexural strengths are the highest,5.13 MPa and 8.02 MPa,respectively.The strength of silica fume / basalt-polypropylene hybrid fiber concrete is significantly improved,The strength is much higher than ordinary concrete and single-fiber concrete.(3)The resistance to sulfate attack of concrete was studied by testing the mass corrosioncoefficient and strength corrosion coefficient.The results showed that the incorporation of silica fume and fiber greatly improved the resistance to sulfate corrosion of concrete.The concrete test blocks with different mixing ratios at 7d and 28 d ages were compared.When the amount of silica powder was 8%,the content of basalt fiber was 0.15%,When the polypropylene fiber content is 0.50%,the mass loss,compressive strength loss and split tensile strength loss are all the smallest,and the test block has the strongest resistance to sulfate attack.In this paper,the mechanical properties and resistance to sulfate attack of silica fume /basalt-polypropylene hybrid fiber concrete are tested.By testing the concrete compressive strength,split tensile strength,flexural strength,and mass corrosion coefficient and strength corrosion coefficient,the research is conducted.Silica fume,basalt fiber,and polypropylene fiber work together in concrete.