Experimental Study On Basic Mechanical Properties And Durability Of Hybrid Fiber Reinforced Concrete

Concrete is still the most widely used material in the world, though it has theshortcomings of low tensile strength, brittleness and easy cracking. Fiber helps to overcomethe concrete’s inborn defects. Compare to single fiber concrete, whose study is relativelymature, hybrid fiber concrete blended with different qualities and different geometric formscan improve the balance of the three-dimensional distribution and the coordination of fibersand aggregates from different levels, and then improve the enhancement efficiency.Through the orthogonal experiment design, this paper has researched the optimizationstudy to the proportion of mixture of C60high-strength concrete, tested the physicalperformance and the strength of28d for concrete mixture, and then the optimal proportion ofmixture was get. It has used range and variance analysis to quantify the influences ofdifferent factors to mechanical properties. By using various amounts of polypropylene fibersand steel fibers to prepare hybrid fiber high-strength concrete under the optimal proportion ofmixture, and the basic mechanical properties and durability properties have studied by testing,it analyzed the influences of hybrid fiber has for improving the toughening effect, frostresistance and anti-corrosion properties of seawater of hybrid fiber high-strength concrete ofC60. The main studies are as follows:First, this paper studied non-doped fiber, single-doped fiber, hybrid fiber and theimpacts of various amounts of fibers on the fundamental mechanical properties (cubecompression performance, axial compression performance, splitting tensile properties andflexural properties) and durability (frost resistance and anti-corrosion properties of seawater)of the high-strength concrete of C60.Second, it made a definition of the index-mixed coefficients formula for evaluatinghybrid effect of hybrid fiber concrete, and systematically analyzed and compared the impactof fibers in different situations on the fundamental mechanical properties and durability of thehigh-strength concrete of C60.The studied results are as follows:First, with the single-doped steel fiber, compression intensity, axial compressionintensity, splitting tensile intensity and flexural intensity of high-strength have improved tosome extent. Single-doped polypropylene fiber has a drop impact on compression intensityand axial compression intensity, while has some improvement to splitting tensile intensity andflexural intensity. When mix single-doped steel fiber and single-doped polypropylene fiber,compression intensity, axial compression intensity, splitting tensile intensity and flexuralintensity of high-strength concrete are better than the concrete without fiber, but the mixtureeffect is due to the fiber proportion.Second, test the compression intensity lost after doing the freeze-thaw test and seawatererosion test for fiber concrete and concrete without fiber, it can be get that the frost resistanceand anti-corrosion properties of fiber concrete is better than concrete without fiber. It was also found that the proportion of hybrid fiber content and can have a significant impact onhigh-strength concrete frost resistance and corrosion resistance.