Study On Waterproofing Technology Of Spherical Hinge-concrete Structure Of Swivel Bridge

In recent years,the number of bridges using the method of swivel bridge is increasing,especially the railway interchange and highway overpass.As the key component of swivel bridge,the spherical hinge has the problems of seepage of foundation pit,water intake of support,corrosion of spherical hinge,pollution and so on,which affect the effect of later construction.Therefore,it is necessary to design anti-corrosion and waterproof measures to avoid this situation.In this paper,the waterproofing technology of the spherical hinge-concrete structure is studied from the two aspects of concrete waterproofing and the steel interface waterproofing of the spherical hinge-concrete,and hope to provide guidance for practical engineering projects.First,prepare four types of concrete,ordinary concrete(C),single-doped polypropylene fiber concrete(PC),single-doped cementitious capillary crystalline waterproofing(CCCW)concrete(SC)doped polypropylene fiber and CCCW concrete,and then their compressive strength,splitting tensile strength and flexural strength were tested.According to the results of basic mechanical properties,the compressive strength,splitting tensile strength and flexural strength of three kinds of concrete C,PC,SC and SPC are greatly improved under different age conditions,which indicates that the addition of polypropylene fiber and CCCW can improve the mechanical properties of concrete,and the effect of the two composite incorporation is significantly higher than that of the two materials alone.In addition,from the point of tensile pressure ratio and flexural pressure ratio,the toughness and brittleness of concrete are greatly improved after incorporation polypropylene fiber and CCCW into concrete,and the effect of single-doped polypropylene fiber is better than that of single-doped CCCW.Secondly,the penetration test of C,PC,SC and SPC was carried out by HP-4.0 type concrete penetrometer.The results show that compared with ordinary concrete C,the relative permeability coefficient of PC,SC and SPC has a great decrease,and the impermeability effect of single cement-based permeable crystalline masterbatch is slightly better than that of composite CCCW and polypropylene fiber,and is far better than that of single-doped polypropylene fiber.According the basic mechanical properties and impermeability of four kinds of concrete,the composite incorporation effect of polypropylene fiber and CCCW is better than that of both.Finally,the adhesive properties between concrete and steel plates of the SBS modified asphalt,polyurethane and unsaturated polyester resin were compared by direct shear test,and the interface treatment form of concrete was found which was closest to the actual engineering effect.The optimum dosage of the three waterproof adhesive materials was determined by fitting analysis,and then the effects of temperature,humidity and freeze-thaw on the shear properties of the three waterproof adhesive materials were studied.The test results show that the concrete interface is treated with scrape are most similar to the actual engineering effect.Under the condition of the surface scrape treatment and fine dosage,the performance of polyurethane in different temperature,humidity and freeze-thaw environment is better than that of the other two kinds of waterproof adhesive materials,which is more suitable for the special climate characteristics in Northeast China.Polyurethane can be used for waterproofing at the spherical hinge-concrete steel interface.