Experimental Research And Analysis On Anti-erosion Ability Of The Shrinkage-compensating Steel Fiber Reinforced Shotcrete

As the development of China’s economic, the coal-based energy demand is also increasing. The coal mine roadway construction environmental is complex, coupled large stress, the stability and service life of rock under great threat. This paper to extend the service life of the mine roadway concrete and improve the construction environment as a starting point, as shrinkable-compensating steel fiber reinforced shotcrete for the study, carried out a systematic laboratory simulation experiments of sulfate and chloride erosion for which affect the durability of the material, and did engineering application in Huainan Mining Group’s Zhu-ji mine.The shrinkage-compensating steel fiber reinforced shotcrete as the sprayed plain concrete for the base material, made of the expansion agent and steel fibers uniformly dispersed in it. Previous tests showed that the new composite materials in the expansion and deformation properties, the basic mechanical properties and crack resistance were better than single-doped expansion agent or steel fiber. On this basis, this paper by means of full-immersion method indoor, different mix of the shrinkage-compensating steel fiber reinforced shotcrete were soaked in the saturated erosion solution, and the compressive strength, splitting tensile and flexural strength of Od,100d,200d,300d were tested.The sulfate attack results showed that:erosion of the strength reached the maximum after100d, slightly decreased in the intensity of erosion after200d compared with100d, the strength further reduced after immersion300d. Sulfate not only failed to reduce the strength of concrete, but increase the intensity in the early erosion phase, also can ease the rate of decline in strength with the extension of the erosion time in certain extent.Sulfate and chloride mixed corrosion test results showed that:the strength the shrinkage-compensating steel fiber reinforced shotcrete increased after erosion100d, reached the maximum intensity in the200d, reduced in300d. In the erosion process, the presence of sulfate increased the chloride ion diffusion coefficient, reduced the corrosion resistance of the concrete to chloride ion, the presence of chloride ions extended the time of each erosion phase, slowed the rate of sulfate damage to the concrete. when the shrinkage-compensating steel fiber reinforced shoterete in the steel fiber volume rate of1.2%, the best match of the expansive agent dosage was8%, the maximum compressive strength, splitting tensile strength, flexural strength of shrinkage-compensating steel fiber reinforced shotcrete in sulfate attack were increased by47.19%,53.32%,33.33%comparing to the injection plain concrete in the same erosion resistance period, and respectively increased46.56%,42.29%,17.46%in the mixture erosion solution of sulfate and chloride,the anti-erosion ability enhanced markedly.On the basis of the laboratory test, the shrinkage-compensating steel fiber reinforced shotcrete in the optimum mix was used in the965-level coal mine roadway of the Huainan Mining Group’s Zhu-ji mine, the results showed that:the material had strong ability to resist erosion, was a new building composite materials with excellent durability, convenient application and promotion for the future engineering practice.