Abstract: This article studies the influence of concrete′s mechanical properties of four kind of special micro-carbon fiber composites under rod, flake(wide and narrow), wave and so on by axis tensile test. Experiments show that the addition of carbon fiber composite materials can be effective and largely improve the tensile strength, strength and flexural strength of concrete. The tensile strength of special micro-carbon fiber composite materials can maximum increase 64% compared with the reference concrete. The grades of reinforced concrete can be increased from C40~C45 to C60; As the increase of the sum of specific surface area of carbon fiber composites, the strength and flexural strength of concrete can both maximum increase 45.6% and 50.6% respectively. Besides, flake carbon fiber concrete is more likely to be broken than wavy under the same size and specific surface area. All of above prove PAN-based carbon fiber composite materials have a better increase of concrete′s toughness.

Key words: special micro, carbon fiber, composite materials, concrete, mechanical properties