Experimental Research On Strength Characteristics Of Cement Curing Acid Contaminated Soil

With the development of industry, the ecological environment pollution gets worse and worse, and a series of environmental problems occur rapidly. The field associated with geotechnical engineering is called environmental geotechnical engineering. Acid soil pollution problems attracted much attention at home and abroad. Cement is widely used as curing acid contaminated soil.In this paper, the clay samples in Nanjing use two indoor simulated experiment methods to study the strength change rules of cement reinforcement acid contaminated soil in various conditions such as acid content, cement content, curing time, solidifying agent, curing environment. Method A:prepare acid contaminated soil firstly, then mix it with cement; Method B:mix acid and cement with soil at the same time. The results are as follows:(1) The unconfined compressive strength is closely related to cement content and sulfate content. In the certain condition of sulfuric acid concentration (2-16g/kg), with the rising of sulfuric acid content, unconfined compressive strength shows a trend of significant decreasing in lower cement content. On the contrary, it slows a trend of slow increasing in high cement content(2) Two indoor simulated experiments show that Method A is better than Method B and it is in accordance with the pollution situation.(3) By using lime or fly ash replace cement to cure acid contaminated soil, the compressive strength of stabilized soil decreases with the lime/fly ash content increasing. But mixing lime, fly ash and cement into a right proportion can improve the strength of stabilized soil effectively.(4) Appearance changes of stabilized soils eroded by sulfuric acid solution have little relation with curing periods, while they have a large relation with the concentration of sulfuric acid. The strength of solidified soil was affected by cement content, concentration of sulfuric acid solution, curing age and other factors. And reasonable cement contents and concentration of sulfuric acid solution can improve the strength of the stabilized soil.