Study On The Durability Of The Compound Plastic Fiber Reinforced Concrete

Many experts and scholars devoted to exploring ways surface concrete performance to improve the ways and measures since Long-term in order to improving its wear-resisting performance, the flexural strength and anti-freeze properties, anti-permeability, increasing the toughness and fatigue resistance, reducing swell-shrink sex and prolonging the service life of cement concrete pavement. Model steel fiber can not only effectively prevent hardening concrete crack and enhance the concrete various mechanical performance indicators, but also the price of model steel fiber is low, completely fight acid-base, good dispersion, easy to mixing, can spray construction,therefore,which has become a modern road cement concrete technology research priorities. In this paper, the author got some Influence laws which were the volume fraction of plastic fiber, sand ratio and water-cement ratio were to anti-wear properties, anti-permeability,frost resistance,flexural strength through taking dimension model steel fiber concrete auxiliary as the research target and using Ternary quadratic orthogonal rotating combination design.Main conclusions gained can be expressed as follow:(1) The anti-wear properties of plastic fiber reinforced concrete decreases first and then increases when sand ratio is increase and increases all the time when the volume fraction of plastic fiber is increase, however, which decreases all the time when the water-cement ratio is increase.the anti-wear properties is 0.0176 kg/m2 which had reduced 95% compared with plain concrete when the volume fraction of plastic fiber is 1%, sand ratio is 0.3, and water-cement ratio is 0.4,(2) Plastic fibers can significantly improve the frost resistance of concrete, and with the increase of number of freeze-thaw, its effect is more apparent. The Relative dynamic elastic modulus of concrete after 50 times the freeze-thaw cycle is 96.23% when the volume fraction of plastic fiber is 1%, sand ratio is 0.4, and water-cement ratio is 0.4.(3) The influence rules are the anti-permeability of plastic fiber reinforced concrete increases first and then decreases when sand ratio is increase and decreases all the time when the volume fraction of plastic fiber and water-cement ratio are increase,(4) The influence rules are the flexural strength of plastic fiber reinforced concrete increases when the volume fraction of plastic fiber and sand ratio are increase and decreases all the time when the water-cement ratio is increase. The optimum proportion of concrete after Comprehensive analysis is better when the volume fraction of plastic fiber is 1%, sand ratio is 0.3, and water-cement ratio is 0.4.