高寒盐沼区桥梁桩基腐蚀损伤试验研究OA

To investigate the corrosion damage mechanism of bridge pile foundation under freeze-thaw cyclesin high-altitude cold saline marsh areas,seven groups of pile foundation concrete specimens with different mix ratios were soaked in three mass concentrations of composite salt solutions.After freeze-thaw cycling,the appearance,mass loss,dynamic elastic modulus and compressive strength were analyzed.Combined with scanning electron microscopy(SEM)test,the corrosion damage mechanism of pile foundation concrete was revealed.The research results show that the ratio of external admixtures has a significant impact on the corrosion resistance performance of pile foundation concrete.The concrete specimens mixed with fly ash,silica fume and expansion agent(Mix ratio V)was soaked and frozen-thawed for 120 times with a mass concentration of 3.17％composite salt solution.The surface of the specimens only fell off slightly,which improved the erosion resistance performance of the pile foundation concrete.When the mass concentration of the composite salt solution increases from 3.17％to 19.2％,the mutual inhibition between salt ions slows down the erosion and damage to pile foundation concrete.It was observed from SEM test that the corrosion products of the concrete specimens mainly include ettringite,Friedel salt,etc.The results of this paper will have important engineering significance for the design,service and operation and maintenance of bridge pile foundations in high-altitude cold salt marsh areas.