The Experimental Research On The Chloride Resistance And Carbonation Of Fiber Concrete

Polypropylene fiber has been widely used in practical engineering, but polyester fiber is rarely used. And polyester fiber are more cheaper than polypropylene fiber on the financial condition. In this paper, I studied the influence of mechanical properties of concrete on content of three basic indicators as the water cement ratio, the dosage of fly ash and the volume polypropylene fiber/polyester fiber with adopting the method of the orthogonal experiment L9(33).Through orthogonal test results contrast analysis of the compressive strength and splitting strength of two kinds of fiber reinforced concrete under the influence of various factors, the optimal combination is obtained. Then we can conduct an experiment about the resistance to chloride ion penetration performance and the carbonation resistance performance of the two optimal combinations.The results show that the mechanical properties of polyester fiber and the resistance to chloride ion permeability and carbonation resistance are better than polyester fiber. Specific conclusions are as follows:(1) Through the orthogonal experiment, the optimal mixture ratio of concrete of the polyester fiber and polypropylene fiber concrete is obtained.The optimal mixing proportion of polypropylene fiber are as follows:the water-binder ratio is0.33, the dosage of fly ash is20%, the volume content of polypropylene fiber is0.9kg/m3. The optimal mixing proportion of polyester fiber are as follows:the water-binder ratio is0.33, the dosage of fly ash is20%, the volume content of polyester fiber is0.9kg/m3. These two experiments are the combination of good working performance and mechanical performance.(2) Orthogonal experiment results show that compressive strength of the concrete mixed with polypropylene fiber and polyester fiber are slightly higher than the benchmark set of concrete.It is improved by3.0%～5.3%, and the degree of influence is not obvious.But the splitting strength and flexural strength are much higher than benchmark concrete, and it is improved by14.2%～15.7%.(3) Through the concrete resistance to chloride ion penetration test contrast research, it shows that the quantity of electricity of the polypropylene fiber concrete is1277.7C, it is lower than the base concrete by10.3%.The quantity of electricity of polyester fiber concrete is1236.3C,it is lower than the base concrete by13.2%. The test results indicate that both polypropylene fiber and polyester fiber improve the resistance to chloride ion penetration performance of concrete and the resistance to chloride ion penetration performance of polyester fiber concrete is slightly higher than that of polypropylene fiber concrete.(4) Through a comparative study on the concrete carbonation resistance test, it shows that in terms of carbide28d, the carbonation depth of polypropylene fiber is lower than that of benchmark concrete by11.7%.The carbonation depth of polyester fiber concrete is lower than that of benchmark concrete by13.6%.The carbonation depth of polyester fiber concrete is lower than that of polypropylene fiber concrete by2.10%.The test results show that the polypropylene fiber and polyester fiber can improve the carbonation resistance of the concrete, and the carbonation resistance of polyester fiber concrete is slightly higher than that of polypropylene fiber concrete.· Through the research in this paper, the mechanical properties, the resistance to chloride ion penetration performance and the carbonation resistance performance of polyester fiber concrete are higher than that of polypropylene fiber. We can make full use of its advantages in the use of engineering and it has certain reference and guidance for practical engineering.