| In order to make the waste sludge obtain the engineering application value and solve the environmental problems brought by the sludge,the strength and mechanical properties of the sludge can be improved by solidifying the sludge.In this paper,the river silt is taken as the research object,and the mechanical characteristics and microstructure of the solidified silt are studied by adding ion curing agent and cement.The compression strength,shear strength,dry wet cycle,impermeability and microstructure of solidified silt samples were studied.The main results of this paper are as follows:(1)According to the unconfined compressive strength test of different cement and ion curing agent at different ages,the best content of ion curing agent is 0.2 ‰ ion curing agent.When the ratio of 0.2 ‰ ion curing agent and 6%cement can meet the requirements of medium light traffic subgrade soil.(2)Through the analysis of two main indexes of cohesion and internal friction angle by shear test,it is found that cement can improve these two indexes in varying degrees,but the performance of ionic curing agent is not obvious.(3)It is found that the performance of dry wet cyclic test sample without adding amount of soil is very low,and adding ionic curing agent alone has no obvious effect,but the combination of ionic curing agent and cement can increase the cycle for 1 to 2 times.(4)The permeability test shows that both cement and ionic curing agent can improve the permeability and reduce the permeability coefficient.The cement and ionic curing agent can reduce 47.4%and 16.9%respectively.(5)Through XRD and SEM experiments,the curing mechanism of solidified samples was explored,mainly including hydration reaction and ion exchange reaction of solidified soil.The factors of strength improvement were analyzed,including cement,ion curing agent,age and other factors.The change of soil elements before and after adding curing agent was described.Figure 36 table 8 reference 81... |
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