Experimental Research Of Fiber Material In "White+White" Ultra-Thin Whitetopping

In past,a large number of cement concrete pavement had been constructed in china.With the development of rapid economy and transportation in our country, many diseases often emerge in the original concrete pavement.In particular, there is a typical disease,which the sinkage of subgrade lead to the whole sinkage of some sections of the concrete pavement panel. A solution is proposed that firstly to deal with the stability of subgrade and secondly break the original road surface, repave a new concrete pavement. However, repavement of a new concrete pavement, is bound to waste the resources of the original pavement, and increase the cost of repairment. Based on this point, the research project proposes the UTW technology.Because thickness of the UTW is thin and UTW is easy to crack, the article is aimed to identify the fiber materials suitable to the requirements of project, in order to improve the flexural tensile strength of UTW concrete and the ability to resist temperature shrinkage stress and achieve the purpose of open traffic as soon as possible.The main conclusions were represented as follows:â‘ The author had summarized the qualitative requirements of UTW to concrete, and screened fiber material and raw materials of concrete.â‘¡Orthogonal experimental method had been used to analyze fiber reinforced concrete mix ratio, theoretically get the best content of steel fiber and the corresponding concrete mix ratio.â‘¢From the aspects of the mechanical performance and pavement performance, the improvements of steel fibers and polyacrylonitrile fibers in the UTW were compared. Finally from the testing point of view, fiber materials and their mix ratio suitable to need of the project were got and met the requirement of open traffic of UTW as soon as possible.â‘£The experimental results also show that: concrete into which adequate volume of steel fibers and polyacrylonitrile fibers were added can improve a variety of concrete mechanical properties, but the PAN fibers are stronger than steel fibers in the resisting flexural strike performance, the preventing crack performance in early days and impervious performance.Experimental study of this paper provides a theoretical and experimental foundation to the application of fiber material into UTW, and will enhance the application of the UTW into the original concrete pavement.