The Research On The Solidification And Mechanical Properties Of Sludge

Sludge with high moisture content, high liquidity, such as faults, it is difficult to be directly used, and silt may cause pollution to the environment, how to silt to recycle waste, is bound to become the top priority. Silt chemical curing is currently the most used a method of the disposal of sludge, although foreign chemical curing agent has grown but the cost is very high, starting from the national conditions of our country, the low-cost high-performance mud curing agent has the vital significance.Based on unconfined compressive strength and direct shear test method to study the curing agent types and dosage on the properties of mud room temperature curing, and based on the orthogonal experiment to optimize the curing agent, the optimal composition, at the same time was studied by triaxial test of mud solidified soil shear failure behavior.Cement, lime, gypsum and sodium silicate as the main curing agent, curing agent is studied through single mixing experiment of curing performance. Research results show that the test content range, for cement and sodium silicate, the unconfined compressive strength of solidified mud casted with the increase of the dosage of cement and sodium silicate, linear increase for lime, gypsum and potassium permanganate, within a certain dosage (2% dosage of gypsum, lime content within 2%, potassium permanganate content within 1.5%), silt unconfined compressive strength increases with the increase of curing agent content, when gypsum and lime content exceeds 2%, more than 1.5% potassium permanganate, intensity with the increase of dosage showed a trend of decrease. Within 1.5% when the dosage of water reducing agent, silt unconfined compressive strength increases with the increase of the dosage of water reducing agent, when the dosage of more than 1.5%, strength as a trend of decrease with the increase of the content.With silt 7 d,28 d unconfined compressive strength as the evaluation indexes, through the orthogonal experiment analysis, the best combination of curing agent were as follows:18%18%, water reducing agent 1.5%, sodium silicate cement,2% gypsum,6% lime. Replace GX04 curing agent.Through the unconfined compression test to analyze the strength of the silt solidification and curing age, GX04 curing agent and curing agent cement the relationship between the dosage. Research has shown that with the increase of cement content, sludge solidification strength also increase gradually, but less than 2%, the dosage of cement strength increase is not obvious. As the growth of the age, raises its silt strength of solidified soil,7 d curing age, due to the insufficient hydration reaction of various curing agents, strength increasing slowly, age at 7 d-28 d intensity relatively fast growth, age more than 90 d, strength and growth trend. With the increase of GX04 curing agent content, the strength of the silt stabilized soil is growing gradually, and when GX04 curing agent content is 2%, strength increasing slowly. Incorporation of GX04 curing agent in promote the growth of silt strength of solidified soil have more advantages.Through triaxial compression test the failure modes of the stabilized soil from silt is analyzed, the results show that the sludge solidification type failure mode with strain hardening, ideal elastic-plastic model, strain softening model, three kinds of concrete damage forms related to the size of the curing agent content and confining pressure. And only mixed cement testing scheme, silt after curing, the scope of the effective internal friction Angle between ° 11 to 18 °; Incorporating GX04 test scheme of curing agent, the effective internal friction Angle between 16 °-21 °, the range of effective cohesive force is growing rapidly, compared with the cement hardening agent group, internal friction Angle and cohesive strength has greatly improved. And by infiltration test, the silt GX04 after curing the permeability performance is better than cement soil solidified sludge.Preparation baking-free brick, the use of cement and GX04 solidified mud preparation baking-free brick tests showed that the optimum water ratio is 10%, the molding pressure 10 mpa-20 mpa, the compressive strength of baking-free brick more than sintered common brick Ievel-mu15 requirements. Preparation baking-free brick cement as curing agent, the optimum proportion of cement admixture is 42%, GX04 as curing agent, the preparation was the optimum ratio of cement admixture is 38%-42%. Under the influence of the ratio of the preparation of baking-free brick freeze-thaw cycle mass loss and strength loss rate has reached the requirement. GX04 curing agent silt preparation was more dominant than concrete curing agent.