Through the sludge solidification technology

the municipal sludge is transformed into a new type of municipal sludge solidified soil. In order to study the engineering properties of the sludge solidified soil

the unconfined strength test

shrinkage test

leaching toxicity test and microstructure test are carried out on the new type of municipal sewage sludge solidified soil. The test results show that the unconfined compressive strength of urban sludge solidified soil increases with the aging period

and basically stable after 28 days. The linear shrinkage of new city sludge solidified soil increases with age

and 28 days later tend to a stable value; compared with city sludge solidified soil after digestion

the leaching toxicity of city sludge solidification in soil decreased

the leaching amount of heavy metals are in line with the requirements of national standard. The peak of calcium hydroxide in the urban sludge after lime digestion diffraction peak is very high; but with the increase of curing age

the diffraction peak of calcium hydroxide in the city sludge solidified soil decreased; the diffraction peak of calcium carbonate increased. Microstructure studies show that there is a large number of fibrous material associated with soil particles and agglomerates of particles of city sludge solidified soil in SEM images

interactive spatial structure of soil skeleton fiber

which improves the strength of the soil.