Experimental Study Of The Relevant Properties Of Hybrid Fiber Reinforced Cement Based Composites

With the rapid development of our country’s urbanization and infrastructure, cement-based composite materials, as structural material of superior performance, gets more and more attention in engineering field. Whether on the development of structural seismic or the performance materials, the performance requirement is becoming higher and higher. The development of high strength and high toughness materials has been the urgent demand of Engineering structure. However, too high intensity will make the material brittleness, so improving the toughness and developing a kind of material with low brittleness and high toughness are the most urgent in engineering practice. At present, adding fiber has become one of the effective ways to increase the toughness of concrete, and many scholars have done in-depth research. The research of this paper is the effect of hybrid fiber mixed with micro steel fiber and PVA on the performance of cement-based composite materials. The test set four hybrid ratio of different fiber volume (Vsteel/Vpva, which are1:1,1:3,1:2,3:1, to optimize the cement composite material. Then the tests of axial compression, cube compression, bending, and tensile are done after manufacturing and maintenance according to the related standards. The research contents of the tests are the relationship between the axial compression strength and the cube compression strength, the tensile strength and the standard cube strength, the tensile strength and the bending strength, and the cube dimensional effect of test specimen, under different fiber volume hybrid ratio. The relationship between stress and strain of the pyramid test-piece and the sound emission characteristic parameters in compression test are analysed finally.The test results shows that there is a liner relationship between axial compression strength and the cube compression strength with little gap, and a exponential relationship between the tensile strength and the standard cube strength and between the tensile strength and the bending strength, and that the dimensional effect is exist, under under different fiber volume hybrid ratio. The dimension has some influence on cement strength, and a conversion relationship exists between them. The fiber volume hybrid ratio also affects the strength. The stress-strain relationship of the pyramid test-piece under different fiber volume hybrid ratio obeys the current research results and the objective laws. The sound emission characteristic parameters got in this paper can be used to analyse the evolution and failure characteristics of damage. The research results on cement-based composite materials added micro steel fiber and PVA have a certain research significance and reference value for engineering practice.