Experimental Study On Compressive Strength And Chloride Ion Erosionresistance Of Fibre Reinforced Concrete

Steel corrosion is the main reason for the durability of Marine concrete structure damage, Chloride ion erosion is the primary cause of steel corrosion inside the concrete. Investigation domestic and overseas shows that, A large number of reinforced concrete structure lead to early degradation due to the erosion of chloride ion in coastal areas. In order to solve this problem, Three kinds of strength grade of concrete (C30, C40, C50) were used as substrate in this paper, Through a separate mixed with roycele fiber, royler fiber and hybrid fiber of two kinds of fibers, experiment about the liquidity of fresh concrete and hardened concrete compressive strength and the chlorine ion erosion resistance of concrete is studied. Among them, the roycele fiber content is1.2kg/m3,2.4kg/m3and3.6kg/m3, royler fiber is2kg/m3,4kg/m3and6kg/m, hybrid fiber content is3.2kg/m3,6.4kg/m3and9.6kg/m3, According to the test results, Summary and analysis the influence of fiber type, fiber content and water-binder ratio on concrete slump, compressive strength, the electric flux and the chloride ion diffusion coefficient. Predict and analyze durability life of fiber concrete through the concrete durability life prediction model. The main research work and conclusions in this article are as follows:(1) Take C30, C40and C50as concrete matrix, Conduct Slump test and cube compressive strength test of fiber concrete which mixed with different fiber type and fiber content, The test results show that the slump of concrete mixture decline with the increase of fiber content, But fiber concrete will keep good workability within a reasonable range of dosage of water reducing agent. The cube compressive strength of concrete is generally slightly reduced when mixed with roycele fiber or royler fiber alone, compressive strength is generally slightly increased when mixed with hybrid fiber, But overall,the Influence of fiber on the compressive strength of concrete is not obvious.(2)6hours electric flux test on different fiber types and content of fiber concrete is carried out according to ASTM C1202method, Results indicate that the electric flux of the concrete reduce inordinately After adding fiber.the electric flux of Roycele fiber concrete and fiber content is inversely proportional relationship; And electric flux of Royler fiber concrete decrease first, then increase and then decrease when fiber content increases, the concrete electric flux is minimum when fiber content is2kg/m3; Hybrid fiber concrete is in minimum electric flux when fiber content is3.2kg/m3, then electric flux increase gradually with the increase of fiber content. The influence of water-binder ratio on the electric flux of concrete is obvious, The concrete electric flux decreased significantly when water-binder ratio reduce. (3) Conduct RCM test on fiber concrete adopting Nordic standard method (NT Buid492). Test results show that the influence of fiber and water-binder ratio on the chloride ion duffusion coefficient of concrete is consistent with which on the electric flux of concrete. Comprehensive test results, when the Roycele fiber content is3.6kg/m3, Royler fiber dosage is2kg/m3, hybrid fiber content is3.2kg/m3and water-binder ratio of0.31, fiber concrete has the best resistance performance to chloride ion erosion respectively.(4) Take a correlation analysis on the results of electric flux test and RCM test results, The calculation of correlation coefficient is r=0.9914, The results show that the electric flux of concrete from test and the chloride ion diffusion coefficient calculated from RCM test results have highly correlation, indicating electric flux test and RCM test results reflect fiber concrete chloride ion erosion resistance with synchronization and consistency.(5) Establish a perdiction model of concrete durability life according to Fick’s second law, Take a prediction on durability life of fiber concrete, The prediction results show that the durability life of concrete has extension of defferent levels after mixing fiber, The size of the three kinds of fibers on concrete’s durability improvement is:royler fiber>hybrid fiber>roycele fiber. In addition, the thickness of concrete cover is also an important factor affecting the service life of concrete durability. The concrete cover thickness should be choosed legitimately according to need of engineering.