The use of steel fiber

Steel fibers are mainly used in the manufacture of steel fiber concrete, steel fiber produced by any method can play a role reinforced concrete.

Enhancement depends on the fiber matrix strength (fm), fiber aspect ratio (steel fiber length l and diameter d ratio, that I / d), volume rate of fibers (fiber percentage of share volume of steel fiber concrete Steel ), the bond strength between the fiber and the matrix (τ), as well as the fiber distribution in the matrix and the orientation (η) of. When the steel fiber reinforced concrete damage, mostly fibers are pulled out and not pulled off, thus improving the bond strength between the fiber and the matrix is ​​one of the main controlling factor in improving fiber reinforced effect.

Steel fiber concrete compressive strength, tensile strength, flexural strength, impact strength, toughness, impact toughness and other properties have been improved greatly.

Combination of steel fiber concrete tensile strength, flexural strength (tensile strength) design equations

The tensile strength of steel fiber reinforced concrete

The tensile strength of steel fiber reinforced concrete can be multiplied by a strength reduction factor obtained by testing to determine the splitting tensile strength 0.80, splitting tensile strength test methods according to provisions of GB J81

The tensile strength of steel fiber reinforced concrete standard value fftk = ftk (1 + αt? Ρf? Lf / df)

fftk, ftk-- tensile strength of steel fiber reinforced concrete standard value, design value;

αt-- steel fiber on the tensile strength of steel fiber reinforced concrete impact factor, should be determined through experiments;

ρf-- fiber volume fraction (ie, volume fraction of steel fiber content)

lf-- steel fiber length

df-- steel fiber diameter or equivalent diameter

lf / df-- steel fiber aspect ratio

Steel fiber reinforced concrete flexural strength

(Flexural strength)

When the steel fiber reinforced concrete for road pavement, airport pavement, or other uses bending strength structural design specifications, and the corresponding curved steel fiber reinforced concrete collective concrete tensile strength grading and use of design values, according to existing national provisions cement concrete pavement, airport pavement design specifications and other industries use.

Steel fiber reinforced concrete flexural strength design value fftm = ftm (1 + αtm? Ρf? Lf / df)

fftm, ftm-- flexural strength steel fiber reinforced concrete standard value, design value;

αtm-- steel fiber on the tensile strength of steel fiber reinforced concrete impact factor, should be determined through experiments;

ρf-- fiber volume fraction (ie, volume fraction of steel fiber content)

lf-- steel fiber length

df-- steel fiber diameter or equivalent diameter

lf / df-- steel fiber aspect ratio