Polyvinyl alcohol water solution expansive soil modifier, preparation method and application thereof

Abstract

The invention discloses an expansive soil modifier, which is solution prepared by polyvinyl alcohol and water according to a certain weight ratio; and the preparation method comprises the following steps: taking the polyvinyl alcohol and the water according to the certain weight ratio, doping an appropriate amount of anhydrous ethanol, heating the mixture in a water bath, fully stirring, dissolving the polyvinyl alcohol in the water, placing for a certain time in the water bath, taking supernatant liquor, and obtaining saturated water solution of the polyvinyl alcohol as the modifier. The modifier is sprayed on the surface of dry expansive soil, the second spraying of the modifier is carried out after the surface of the expansive soil is dry, after a plurality of times of spraying of the modifier, a surface modification layer with a certain thickness can be formed, thereby eliminating or reducing the expansion-shrinkage property of a soil body in the modification layer; and the test result shows that the free expansion rate of the expansive soil which is taken out from 90cm to the soil surface is reduced from the original 50 to 37 through the free expansion test, thereby meeting the requirements of engineering construction.

Description

technical field [0001] The invention relates to an expansive soil improver, in particular to a polyvinyl alcohol aqueous solution expansive soil improver for reducing swelling and contraction of expansive soil, a preparation method and application thereof. It belongs to the technical field of geotechnical engineering. Background technique [0002] Expansive soil has been found in most areas of our country. When using expansive soil as engineering soil, it must be further processed due to its large expansibility. There are two types of methods to reduce the expansion and contraction of expansive soil and increase the stability of expansive soil foundation and slope: physical method and chemical method. [0003] Physical methods are: [0004] (1) Surface water protection: set up various drainage ditches and establish a surface drainage network system to make it difficult for surface water to seep into the soil; [0005] (2) Slope protection. At present, the main reinforceme...

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Problems solved by technology

However, the method of improving expansive soil by combining inorganic modifiers and organic modifiers has not been popularized and applied in actual engineering so far, and the results are still in the stage of indoor experiments. This is not only related to the incompleteness of the test results, but the construction is complicated or expensive. High is also the main reason