Experimental Study On The Organic Acid Corrosion For Cemented Soil Of Peat Soil

The research object of this paper is to study the cemented soil of peat soil of lacustrine facies in Kunming, and respectively discussing the relationship among unconfined compressive strength of cemented soil of peat soil and cement mixing ratio and curing age and the destroy behavior produced by erosion of organic acids for cemented soil of peat soil and interaction mechanism between them through indoor unconfined compressive strength test and corrosion test of organic acid for cemented soil of peat soil in this paper. This paper mainly did the following research work:(1)The experimental study for the regularity of the unconfined compressive strength of cemented soil of peat soil changes with mixing amount of cement. The experiment results show that unconfined compressive strength increases with increase of the ratio of cement mixing, and increasing along with the growth of curing age, assuming growth of approximately logarithmic curve, and the strength growth rate of cemented soil of peat soil becomes smaller and smaller along with the growth of curing age.(2) The erosion experimental study of citric acid for cemented soil of peat soil. The experiment results show that citric acid has a strong erosion for cemented soil of peat soil, and the erosion mechanism is that the joint action of acid erosion caused by hydrogen ion and the dilation and erosion caused by citric acid root. And acid consumption changing regularity with time can be divided into two process which includes rapid growth and slow growth, and the regularity of acid consumption rate changing over time can be divided into two process that includes falling fast process and relatively stable process, the acid consumption and acid consumption rate increase with the decrease of the PH value under other conditions being the same. And relative residual strength of cemented soil of peat soil increases with the increase of PH value and increases with the increase of immersion time. The damage strain of the cemented soil of peat soil under different PH value is between 0.05-0.07, and damage of cement-stabilized soil samples is plastic failure and there is still some residual strength after damage. The change rates of unconfined compressive strength of cemented soil of peat soil in 3d and 7d are greater than zero, the strength increases, and less than zero in 14d,28d and 60d, its strength reduces, and the 7d is strength decreasing inflection point time.(3) The erosion experimental study of oxalic acid for cemented soil of peat soil. The oxalic acid solution has corrosion on cemented soil of peat soil. The surfaces of samples generate white granular crystal precipitation in this process of the erosion. The erosion process of oxalic acid for cemented soil of peat soil is a rather complex decomposition and recrystallization process, and this process can be divided into falling process and slow reaction process, the erosion mechanism is that the joint action of acid erosion caused by hydrogen ion and the dilation and erosion caused by oxalate denominationby. And the erosion mainly includes the decompose of cement hydration products of cemented soil of peat soil and ferrous oxide of peat soil, and recrystallization generated insoluble calcium oxalate (CaC2O4) and ferrous oxalate (FeC2O4) crystal, eventually making the soil skeleton connections of cemented soil of peat soil change and forming a new frame structure.