Expanded soil improver based on industrial organic solid wastes, and application of expanded soil improver

Abstract

The invention discloses an expanded soil improver based on industrial organic solid wastes, and application of the expanded soil improver. The expanded soil improver is prepared from the following components by mass percent: 70-76% of lignin, 12-15% of calcium chloride and 12-15% of coal ash. The expanded soil improver is evenly mixed with expanded soil, and the mixture is compacted and molded andis then cured to a prescribed age. The preparation of the expanded soil improver comprises the following steps: 1, carrying out spray-drying on industrial pulping and papermaking waste liquid to obtain the lignin; 2, drying waste carbide slag of acetylene manufacturing plants in the air so as to enable the water content of the waste carbide slag to be reduced to 10% or below, then mixing the dried waste carbide slag with waste hydrochloric acid, and carrying out a reaction under the condition of heating so as to obtain the calcium chloride; 3, evenly mixing the lignin, the calcium chloride and the coal ash with grade F so as to obtain the expanded soil improver. The free swelling ratio of the expanded soil improved by using the expanded soil improver is obviously reduced; the expanded soil improver is environmentally friendly and low in price, thus being wide in application prospect; the application method of the expanded soil improver is simple, economical and high in operability.

Description

technical field [0001] The invention relates to the field of geotechnical engineering or road engineering construction, in particular to an expansive soil modifier based on industrial organic solid waste and its application. Background technique [0002] Expansive soil is a special kind of soil, which has the characteristics of high particle dispersion, high clay mineral content, and sensitivity to environmental humidity and heat changes. This kind of soil absorbs water, swells and softens, loses water, shrinks and cracks, and is one of the common disastrous soils in engineering construction in my country. After the expansive soil subgrade is soaked in water, the subgrade soil swells, and a "fluffy layer" or "plasticine" appears on the surface; after drying and dehydration, the soil shrinks and cracks, and rainwater can directly enter the depth of the soil through the cracks, reducing the bearing capacity of the subgrade. In severe cases, disintegration, uplift and partial ...

AI Technical Summary

Problems solved by technology

Although these materials show excellent performance in improving strength and durability, reducing expansion rate and permeability, etc., there are still certain defects in the context of modern engineering construction needs and green development: (1) cement, lime and other materials The production of cement requires a large amount of non-renewable fossil energy and consumes natural resources such as natural clay; (2) Harmful gases such as carbon dioxide, dust, and sulfur dioxide emitted during the manufacturing process aggravate the greenhouse effect and threaten the safety of the surrounding environment; (3) cement The pH value of improved soil such as soil and lime soil is strongly alkaline, and the service life of underground structures such as concrete and steel structures is seriously affected in this alkaline environment

At present, my country has not effectively utilized lignin, a by-product of pulping and papermaking, and about 95% of the waste is directly discharged into rivers or concentrated and burned as fuel. The efficiency of resource utilization is very low.

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