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Study On Mechanical Properties And Chloride-penetration Resistance Of Concrete With Silicon Powder And Polypropylene Fiber

Posted on:2015-02-19Degree:MasterType:Thesis
Country:ChinaCandidate:D ZhanFull Text:PDF
GTID:2252330428462343Subject:Structural engineering
Abstract/Summary:PDF Full Text Request
The paper combined with local practical of ning xia, we can take silicon powder and fly ash as mineral admixture to substitute cement partly, and mix polypropylene fiber together so that they may enhance the functions of performance concrete. Through the orthogonal experiment and parallel group comparison test. Silica fume and polypropylene fiber has influence on concrete strength, chloride-permeation behavior and drying shrinkage behavior, then analysising the superposition effect and optimization mechanism to provide reference for practical engineering application. The main research results are listed as follows:1.Obtain the optimal mix proportion of silicon dust polypropylene fiber concrete through orthogonal experiment:the water-binder ratio is0.32, the optimized SP is42%, the dosage of siliceous dust, fly ash and polypropylene fiber are5%,15%and0.9kg·m-3respectively.2. The range analysis of orthogonal test’s data shows that the influencing significant size order of five factors includes water-binder ratio(A)、fly ash(B)、silicon powder(C)、polypropylene fiber(D)and SP(E)and for the compressive strength of7days’concrete is A>E>C>B>D; for the compressive strength of28days’concrete is A>E>B>D>C; for splitting tensile strength of28days’ concrete is A>D>E>B>C.3. Compressive strength of parallel test, the early compressive strength of fly ash concrete was lower, the middle and later compressive strength of fly ash concrete was greatly developed; the early compressive strength of mixing with fly ash and siliceous dust of concrete was bigger than fly ash concrete’s; In the condition of certain dosage of fly ash and silica fume, adding0.6kg·m-3PP fiber can improve the compressive strength of concrete; When the contents is more than0.6kg·m-3, the concrete compressive strength decreased with the increase of dosage.4.The test of concrete resistancing to chloride-penetration shows that optimal PFS1group concrete electric flux is770Q after6h, compared with the reference concrete reduces871.8Q.chloridion permeability is extremely low.5.The test of concrete drying shrinkage shows that concrete age and the shrinkage rate conformed to logarithmic function; the drying shrinkage of mixing with fly ash and siliceous dust of concrete was significantly lower than the reference group, In the condition of certain dosage of fly ash and silica fume, when the contents of polypropylene fibers is less than or equal to1.2kg·m-3, Concrete shrinkage decreased with the increase of dosage.
Keywords/Search Tags:siliceous dust, polypropylene fibers, compressive strength, chloride penetrationresistance, drying shrinkage
PDF Full Text Request
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