Research Of Mechanical Properties For Basalt And Polypropylene Mixed Fiber Concrete

In this paper,the reinforcement effect of fiber to concrete is discussed by means of theoretical analysis and experimental research.The content of basalt fiber 1kg/m~3,2kg/m~3,3kg/m~3,4kg/m~3,5kg/m~3,6kg/m~3and the content of polypropylene fiber0.3kg/m~3,0.6kg/m~3,0.9kg/m~3,1.2kg/m~3,1.5kg/m~3,1.8kg/m~3with basalt fiber and polypropylene fiber were mixed by way of its compressive strength test,splitting tensile test,single point cross flexural performance test.After comparing and analyzing the test results of mechanical properties and obtaining the best fiber content,the test of ring restraint and crack resistance is carried out with the best mixing amount,which is compared with plain concrete,and the crack rating is judged.Through the mechanical performance test,it is concluded that basalt fiber and polypropylene fiber have little effect on the compressive strength of concrete,but can significantly improve the tensile strength and flexural strength of concrete.The compressive strength of the plain concrete is 38.4MPa,tensile strength is 2.89MPa,and the flexural strength is 4.08MPa.When the basalt fiber is added alone,the best volume is 3kg/m~3,and the compressive strength is 39.0MPa,which is 1.56%higher than that of plain concrete.;Its tensile strength is 3.35MPa,which is 15.92%higher than that of plain concrete;and its flexural strength is 4.83MPa,which is 18.38%higher than that of plain concrete.When the polypropylene fiber is added,the best content is 1.2kg/m~3,and the compressive strength is 38.5MPa,which is 0.26%higher than that of plain concrete;Its tensile strength is 3.42MPa,which is 18.34%higher than that of plain concrete;and its flexural strength is 4.72MPa,which is 15.69%higher than that of plain concrete.Among them,basalt and polypropylene fiber concrete mixed with comprehensive test effect is the best,the best fiber content is basalt fiber content 3kg/m~3,polypropylene fiber content 1.2kg/m~3.At the optimal content of the compressive strength of 38.2MPa,reduced by 0.52%compared with plain concrete;tensile strength reaches the maximum value of 3.59MPa,compared with plain concrete increased by 24.22%;the flexural strength reaches a maximum of 5.15MPa compared with plain concrete increased by 26.23%.The optimum mixed amount of basalt fiber 3kg/m~3,polypropylene fiber 1.2kg/m~3do experiment on crack resistance of single doped fiber concrete,basalt fiber 3kg/m~3,polypropylene fiber 1.2kg/m~3 do experiment on crack resistance of mixed fiber concrete under the optimum fiber content.Compared with plain concrete,the crack of basalt fiber reinforced concrete to reduce the coefficient of 80.2%,cracking of polypropylene fiber concrete to reduce the coefficient of 82.5%,crack basalt and polypropylene fiber concrete reduce coefficient is 90.6%,three kinds of fiber reinforced concrete crack are a grade.The crack reduction coefficient of the basalt and polypropylene fiber concrete is the highest,and the crack resistance test results are the best.