The Chlorine Ion Penetration Study Of Fiber Lithium Slag Concrete Beams Under Coupling Between Loading And Chloride Salt

Xinjiang has a large scale lithium salt production base,with the continuous progress and development of society,people's increasing demand for lithium salts.A large number of lithium salt products caused a large number of lithium slag waste,not only occupy space,but also a threat to air quality.With the right amount of lithium slag instead of cement mixed concrete,not only to solve the problem of waste accumulation,but also get better performance,more economical concrete,one after another.The appropriate amount of low modulus polypropylene fiber into concrete can improve the internal pore structure,improve the degree of compaction,and then make the concrete in crack resistance,tensile strength and durability and other aspects have a better performance.From the results of previous studies this topic group,considering the mechanical performance and durability,the lithium slag replacement ratio is 20% based on the research of polypropylene fiber and polypropylene 1.2kg/m3 doped polypropylene fiber concrete and reinforced concrete beams under performance:1.The effect of chloride ion erosion time on the mechanical properties and the penetration depth of chloride ions was studied by means of cube compressive test,prism compressive strength,splitting tensile strength and chloride ion penetration depth test.The results show that the chloride ion erosion of small test block strength effect,but with the increase of time erosion of chloride penetration depth increases gradually;the incorporation of little effect of polypropylene fiber on concrete compressive strength,when can significantly improve the splitting tensile strength,enhance the integrity of concrete at failure.2.After coupling,concrete beams of two kinds of material bending test,research on the coupling time,stress ratio and polypropylene fiber on lithium slag concrete beam failure process,cracking load,ultimate load and the load deflection curve effect.The results show that all the beams were reinforced damage effect of concrete beam coupling on the ultimate load,load deflection curve is not obvious,the cracking load increases with the coupling time and stress increase,but when the stress ratio is 0.7 when the cracking load decreases.The cracking load,ultimate load,flexural rigidity,deflection and integrity of the lithium slag concrete beam are improved by adding polypropylene fiber.3.Through the determination of chloride ion concentration at the depth of the test beam is obtained the distribution of chloride ions in concrete beams,according to the Fick's second law relation between the calculated surface chloride concentration C_s and chloride ion permeability coefficient D_e,and then get the coupling time,stress,the stress in the category and mixing effect of polypropylene fiber on the beam of chloride lithium slag concrete.Finally,the mathematical model of surface chloride concentration C_s and chloride ion permeability coefficient D_e is established.