Effect of Fly Ash Content in Tunnel Lining Concrete on Chemical Crystallization in Drainage Pipes
In this study,groundwater and crystallization samples in drainage pipe from multiple tunnels were collected,and microscopic and chemical composition analysis were conducted. An experimental setup was established to simulate the tunnel drainage pipe system. The impacts of different amount of fly ash dosage on concrete were studied,including the total alkalinity of the test solution,the quality and the microstructure of pipe crystallization. It was found that the tunnel crystallization samples were primarily composed of high-purity calcium carbonate,and the content of magnesium affected the shape of the crystallization. High magnesium content resulted in irregular crystallization,while low magnesium content resulted in more stable rhombohedral crystallization. In the experiment,as the dosage of fly ash increased,the total alkalinity rose in the solution,and the accumulation of crystallization initially decreased and then increased. The experimental group with a 10％ fly ash dosage exhibited the fastest rate of crystallization accumulation,while the experimental group with a 15％ dosage showed the slowest,with a significant difference between them in terms of accumulation amount. The microstructure morphology of the crystallization from the experimental setup was similar to that of the samples,mainly consisting of rhombohedral calcite crystals of calcium carbonate. The fly ash dosage had no significant impact on the microstructure morphology and surface features of the crystallization.
tunnelscrystallization in drainage pipescalcium carbonateindoor model testsfly ash concrete
万方数据
维普
