The Mechanics And Durable Performance Study Of Red Clay Composite Cement In Low Dosage

Cement composite soil, with its low cost, low carbon environmental protection, is widely used in the highway pavement base, the water engineering slope reinforcement, the lining of seepage prevention and the construction engineering projects such as soft soil foundation treatment. This paper analyzes the performance of the cement-soil after adding coal fly ash in the abandoned power plant and polypropylene fiber chopped silk in the cement-soil. And provide theoretical reference for practical engineering through experimental research.First of all, select the optimum mixture ratio in the various combinations that are using the orthogonal principle of four factors three levels through the orthogonal experiment. Through poor statistical analysis method and variance statistical analysis method it is concluded that:Dosage of cement and fly ash have significant effect on the unconfined compressive strength of cement-soil, yet the polypropylene fiber content and moisture content of the code have little effect. And it is got that the optimal mixture ratio in the scope of this study is that 10% cement,16% fly ash, 0.12% polypropylene fiber,18% moisture content.Secondly, the erosion tests of different concentrations of sodium chloride solution are carried out on the soil-cement block of the optimal mixing proportion. Through the analysis it is concluded that the quality and the intensity of the blocks follow the trend of development of decrease after the first increase with the increase in the number of erosion. The strength of the blocks changed little with the increase in the number of erosion in a certain range of concentration of NaCl solution, but the strength of the block decline significantly as the increase in the number of erosion when the concentration is beyond the particular boundaries, It shows the great Cl-concentration enhance the erosion of soil-cement block significantly, and the soil block is damaged more serious.Again, the freezing-thawing cycling tests is carried with the optimal group A and its control group B、C、D, after a series of analysis it is concluded:Each block in the process of freezing-thawing show the trend of decrease after first increase of the quality, and the strength of every group presents the trend of decreasing; but the quality and strength loss of the optimal group A are smaller than the other three contrast group after freezing-thawing cycle 20 times.In order to conduct further research, it studies the block from the micro aspect combined with the electron microscope scanning test, and carries the analysis of the mechanism on the above basis.