Study On Properties For Crack Resistance And Impermeability Of Fiber Concrete In Underground Structure

With the development of social economy, citifying process, for remission aboveground space pressure, High-rise buildings and large-scale construction of public buildings to the underground space development to the concept of evolving. Underground structures have been built for almost the leakage of pieces of pieces of the project status, try to make it in the design, materials, construction and other measures taken to alleviate the leakage of underground structures. Underground project suffered erosion in concrete rather complicated, External environment can not be changed, therefore, to improve the underground works of the leakage of concrete from the concrete to reduce the internal defects and the composition of materials to improve their start.In this paper, a study from the materials, using fiber reinforced concrete to improve the leakage of underground engineering status.Steel fiber has been taken into account the maturity of the study, using the method of same volume fraction less, adding dula fiber, basalt fiber of different longth into concrete matrix specimens, experimental study of slump, compressive strength, crack resistance and impermeability. In view of the traditional test plate poor speech rehabilitation, in crack resistance test, using kinfe-edge method, and two anti-cracking of the comparative analysis of test methods, crack indicators make more scientific test results.Durability of concrete involved in three criteria:strength, permeability and anti-cracking ability. Impact factors based on the impermeability of the more complex, there are more test methods, according to the specific characteristics of various methods, using electron flux method, the durability of fiber reinforced concrete and comprehensive analysis and evaluation indicators, eventually apply to underground structures to determine the durability requirements of the optimal ratio of fiber reinforced concrete. In view of the reliability of the existing standards to identify aspects of fiber reinforced concrete in the imperfect, national standards for concrete structures in service of the crack width and deflection requirements of certain, basing on tests for crack resistance of fiber concrete, according to the measured value for crack width of plain concrete, after the adding for characteristic parameters of fiber, establishes the limits state equation and confirms the random variable; using the center point method, reliability index to achieve the ultimate.In this paper, fiber reinforced concrete on the theoretical and experimental study of a series of seminars, Give full play to their potential for materials, maintenance and optimization of the ground floor of the structure of the application of the ground structure to promote a constructive and practical application of value engineering.