| The development of modern industry has become more and more vigorous,and Portland cement has become an indispensable material for solidifying soil.However,the large-scale use of cement is accompanied by environmental pollution and other problems.The production and use of cement will cause indelible pollution to the environment.Therefore,it is urgent to find green and environmentally friendly alternatives.Silica fume has an important effect on improving the early strength,and at the same time,it can effectively refine the internal pore structure of the cement slurry and effectively reduce the proportion of macropores.Blast furnace slag is an industrial by-product,and its internal chemical composition is similar to that of cement,which can be used as a partial substitute for cement.In this paper,slag,silica fume and low-content cement are used as curing agents.After a series of laboratory tests and theoretical analysis,the strength and durability of the solidified soil test block mixed with the new solidifying agent are studied,and the solidified soil is analyzed by microscopic experiments.Internal curing mechanism.The main conclusions are as follows:(1)Through the experimental analysis of the strength characteristics of the solidified soil,the results show that: The compressive strength of the solidified soil test block was obviously improved after adding blast furnace slag and silica fume;On the basis of the fixed amount of curing agent,six different proportioning schemes are proposed,and it is proved by experiments that the ratio of slag to silica fume is 2:1,the best effect;The best ratio combination was selected,and the quantitative curing agent was added according to the design of the test plan.It was found in the experiment that the compressive strength of the test block was improved.When the curing age is 28 d,the compressive strength of the CG-SF-stabilized soil with a total content of curing agent of 30% is 76.95% higher than that of the CG-SF-stabilized soil with a total content of curing agent of 12%;The compressive strength of the test block is positively correlated with the curing time,and the compressive strength of the sample with the best ratio of 90 d age can reach more than 2.7 times of its 7d age.(2)The standard curing of the solidified soil test block was carried out to 28 days,and the frozen-thaw cycle test was carried out on the solidified soil test block with different contents.The test results showed that: After the number of indoor freeze-thaw cycle tests increased,the mass loss rate of the solidified soil test block increased,and the unconfined compressive strength decreased.(3)The standard curing of the solidified soil test block was carried out to 28 days,and the dry-wet cycle test of the solidified soil test block with different contents showed that: With the continuous dry-wetting cycle test,the mass loss rates of the CG-SF group and the ordinary group of solidified soil test blocks both showed an upward trend,and the unconfined compressive strength showed the characteristics of increasing first and then decreasing.(4)The standard curing of the solidified soil test block was carried out to 28 days,and the erosion test of the solidified soil test block with different dosages showed that:In the case of erosion in different solution environments and a certain amount of curing agent,the strengths of the test blocks are in the order of clear water group>chloride group>mixed solution group>sulfate group.The erosion resistance of the CG-SF group of solidified soil is better than that of ordinary solidified soil.Figure [46] Table [11] Reference [83]... |
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