Testing Research On Doped Nano-Silica Steel Fiber Reinforced Concrete

Doped nano-SiO2 steel fiber reinforced concrete is a kind of new composite material with excellent properties. As compared with conventional concrete, doped nano-SiO2 steel fiber reinforced concrete possesses high strength, high toughness and high durability,etc. An experimental research on the behaviour of fiber reinforced high-strength concrete under compression, split and rupture was performed in this paper. The main achievements are as follows:1.Through the experiments on 207 doped nano-SiO2 steel fiber reinforced concrete specimens with the dimensions of 100mm×100mm×100mm, the effects of steel fiber's volume fraction, nano-SiO2 content, conserve age and concrete grade on cubic compressive strength were investigated.The experiment results showed,nano-SiO2 can improve cube compressive strength,especially in the early stages;the effects of steel fiber on cubic compressive strength is small;Along with the concrete strength grade and curing age growth, the cube compressive strength increases.2.Through the experiments on 207 doped nano-SiO2 steel fiber reinforced concrete specimens with the dimensions of 100mm×100mm×100mm, the effects of steel fiber's volume fraction, nano-SiO2 content, conserve age and concrete grade on cubic compressive splitting strength were investigated. The experiment results showed,nano-SiO2 can improve the splitting tensile strength of grain concrete,but to steel fiber reinforced concrete, the effect is small; Steel fiber had remarkable effect on splitting tensile strength of the concrete admixture of nano-SiO2;along with the concrete strength grade and curing age growth, the splitting tensile strength increases.In addition,the relationship between splitting tensile strength and compressive strength was studied.3.Through the experiments on 207 doped nano-SiO2 steel fiber reinforced concrete specimens with the dimensions of 100mm×100mm×400mm, the effects of steel fiber's volume fraction, nano-SiO2 content, conserve age and concrete grade on cubic breaking strength were investigated. The experiment results showed,nano-SiO2 can improve the flexural strength of grain concrete and steel fiber reinforced concrete;Steel fiber had remarkable effect on flexural strength of the concrete admixture of nano-SiO2;along with the concrete strength grade and curing age growth, the flexural strength increases.In addition,the relationship between breaking strength and compressive strengthwere studied.4.Through the experiments on 46 doped nano-silica steel fiber reinforced concrete specimens with the dimensions of 150mm×l50mm×300mm, the effects of steel fiber's volume fraction, nano-silica content, conserve age and concrete grade on axial compressive strength were studied. The poisson's ratio of nano-SiO2 steel fiber reinforced concrete was investigated. Established the constitutive model for the axial compression stress-strain curve.