Research method for frost resistance of lignin-modified silty clay

Abstract

The invention discloses a research method for frost resistance of lignin-modified silty clay. The method comprises the following steps: S1. air drying the silty clay, and screening out granular siltyclay; S2. doping the the screened silty clay with lignin; S3. uniformly stirring silty clay samples with different lignin doping ratios, performing sealed infiltration for 12h, forming a cylindrical test piece by using a static pressure method, culturing the cylindrical test piece in a sealed manner at constant temperature and constant humidity, and then performing a freezing and thawing cycle test; S4. performing a repeated loading dynamic rebound modulus test on the test piece before and after the freezing and thawing cycle test; S5. performing a bearing ratio test on the test piece before and after the freezing and thawing cycle test; and S6. performing a heat conductivity coefficient test on the test piece before and after the freezing and thawing cycle test. By adopting the research method for frost resistance of lignin-modified silty clay disclosed by the invention, the blank of the research on the road performance of an industrial by-product in cold regions, that is, the lignin-modified silty clay, under a freezing and thawing cycle condition is filled.

Description

technical field [0001] The invention relates to the field of research on properties of lignin-improved silty clay, in particular to a method for researching the frost resistance of lignin-improved silty clay. Background technique [0002] In seasonally frozen areas, the subgrade soil thaws in spring, and the water content of the subgrade soil increases due to the melting of ice crystals accumulated on the upper part of the subgrade soil layer. In addition, the silty clay soil has poor drainage capacity, and the upper layer of the subgrade layer softens and its strength decreases. Under the repeated action of vehicle loads, structural rutting appears on the road surface in light cases, which limits the driving speed; in severe cases, the road surface cracks, mud emerges, and the subgrade deforms too much and becomes unstable. [0003] In recent years, during the investigation of road operation conditions in northern severe cold regions, it was found that the subgrades filled ...

AI Technical Summary

Problems solved by technology

[0003] In recent years, during the investigation of road operation conditions in northern severe cold regions, it was found that the subgrades filled with silty clay have significant freezing damage. The application of lignin-improved silty clay in subgrade engineering in cold regions requires exploratory research on its engineering properties and durability. However, there are few reports on road performance of cohesive soil improved by industrial by-product lignin in cold regions under freeze-thaw cycle conditions, and its engineering application and effect evaluation are very lacking.

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