Study On The Influence Of Chlorine Salt Concentration And Fiber Admixture On The Durability Of Face Concrete

As an important anti-seepage structure of concrete face rockfill dam,the durability of concrete slab is very important for the long-term safe operation of the dam.However,under severe environmental conditions,the salt solution erosion and freezing erosion in the water environment often cause certain damage to the concrete panel structure.Studies have shown that the incorporation of fibers into the panel structure can improve the durability of the fiber panel concrete to a certain extent.Therefore,it is of great reference significance to select the fiber in practical engineering to carry out the relevant research on the influence law of the fiber admixture method on the salt concrete erosion resistance of the panel concrete.First of all,according to the relevant specifications,this article strictly designs the mix ratio of panel concrete,and performs basic performance tests on the prepared panel concrete to ensure that the prepared test piece meets the requirements of panel concrete;second,for the influencing factors of chloride salt concentration,the same fiber varieties are different Under the condition of chloride salt concentration,the quick freezing method was used to conduct a salt freeze cycle test on the test piece to explore the salt freezing resistance performance of the fiber panel concrete under the erosive environment of different chloride salt concentrations;then,the influence factors of fiber content and hybrid fiber,Maintain the same chloride salt concentration,and conduct salt freeze cycle tests to explore the influence of fiber content and hybrid fibers on the resistance of the panel concrete to salt freeze corrosion;Finally,use an electron microscope scanner to observe the fiber panel concrete after the salt freeze cycle corrosion test The internal morphology of the structure,analyze the internal damage of the structure from the perspective of micro morphology.Research indicates:(1)The increase of the chloride salt concentration will aggravate the damage of the fiber panel concrete by salt freeze erosion,but the excessively high chloride salt concentration will reduce the freezing point to a certain extent,make the solution freezing speed slower,and instead damage the test piece.light.(2)Polypropylene fiber can effectively improve the durability of the panel concrete against salt freeze corrosion,and different amounts of fiber have different degrees of improvement.In this test,the polypropylene fiber with an amount of lkg/m3 has the best effect on improving the durability of the panel concrete against salt freeze corrosion.Polyacrylonitrile fiber panel concrete and polypropylene fiber panel concrete are similarly affected by salt freeze erosion:fibers with too high a content are easily dispersed and uneven,and it is inevitable that agglomeration occurs,making the internal stress of the structure uneven and more susceptible to salt freeze erosion Destructive effect.The greater the amount of steel fiber,the lighter the specimen is eroded,because the selected amount of steel fiber does not cause excessive agglomeration.(3)Hybrid fiber panel concrete is more conducive to the salt frost resistance of the panel concrete than the single-mixed fiber panel concrete,but when the steel fiber content is large,the single-mixed steel fiber specimens also perform better;polypropylene-polypropylene The nitrile hybrid fiber panel concrete is not as resistant to salt freeze corrosion as the steel fiber-containing hybrid fiber panel concrete.The research results of this article can be used for reference in the related research in the future,and can provide reference for practical engineering.