To study the effect of fiber and rubber content on the properties of cement-based materials for coal mines,cement mortars prepared with water-cement ratio of 0.34 and different kinds of fiber and rubber content were prepared.Uniaxial compression test was carried out on cured specimens with MTS testing apparatus.The results show that the compressive strength of specimens without fiber and with fiber in 14 days can reach 30 MPa,and it increases slightly on 28th days.The compressive strength of all specimens decreased significantly with the increase of rubber substitution rate.The peak strain of the non-fiber specimens decreases firstly,then increases and finally decreases with the increase of rubber substitution rate on 28th day.The toughness of the specimen mixed with 2%polyethylene fiber increased obviously.The compressive strength of the specimen with 2%steel fiber increased obviously.The growth rates of input energy,elastic energy and dissipative energy are weakened with the increase of rubber substitution rate but strengthened with the increase of fiber content.With the increase of rubber substitution rate or the addition of steel fiber,the dissipated energy step increases to different degrees,the elastic energy release rate decreases significantly,and the crack resistance of the specimen is favorable.Cement-based materials are divided into 5 types according to material properties,such as high ductility,high strength,high toughness,impact resistance and durability,and the economic cost of the materials is analyzed.The research can provide reference for improving the properties of cement-based materials and optimizing the material formulation,and thus provide technical support for the engineering practice and sustainable development of using high toughness materials in coal mines.
维普
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