Research on the Dynamic Mechanical Properties and Energy Dissipation of Expansive Soil Stabilized by Fly Ash and Lime

Abstract

To probe into the dynamic mechanical properties of expansive soil stabilized by fly ash and lime under impact load, the split-Hopkinson pressure bar (SHPB) test was carried out in this study. An analysis was made on the dynamic mechanical property and final fracture morphology of stabilized soil, and the failure mechanism was also explored from the perspective of energy dissipation. According to the test results, under the impact pressure of 0.2 MPa, plain soil and pure fly ash-stabilized soil exhibit strong plasticity. After the addition of lime, the stabilized soil shows obvious brittle failure. The dynamic compressive strength and absorbed energy of stabilized soil first increase and then decrease with the change of mix proportions. Both the dynamic compressive strength and the absorbed energy reach the peak value at the content of 20% fly ash and 5% lime (20% F + 5% L). In the process of the test, most of the incident energy is reflected back to the incident bar. The absorbed energy of stabilized soil increases linearly with the rise of dynamic compressive strength, while the absorbed energy is negatively correlated with the fractal dimension. The fractal dimension of pore morphology of the plain soil is lower than that of the fly ash-lime combined stabilized soil when it comes to the two different magnification ratios. The test results indicate that the modifier content of 20% F + 5% L can significantly improve the dynamic mechanical properties of the expansive soil.

Energy Dissipation and Electromagnetic Radiation Response of Sandstone Samples with a Pre-Existing Crack of Various Inclinations under an Impact Load

“…Liang [9] believed that the absorbed energy of the sample showed a significant increasing trend with the continuous increase and increase in temperature and impact velocity. Zhou [10] discussed the damage mechanism of the specimen from the energy point of view through impact and dynamic experiments. Li [11] and Huang [12] both conducted impact dynamics experiments on samples and believed that the energy dissipation density increased with the increase in the fractal dimension.…”

Experimental Study on Mechanical Properties of Fly Ash Stabilized with Cement

“…At present, the split Hopkinson pressure bar (SHPB) device has been extensively applied to assess the dynamic mechanical properties exhibited by the materials with a strain rate of 10 2 s −1 -10 4 s −1 [19,20]. Chen et al [21] adopted the method of SHPB to carry out a study on the dynamic mechanical properties of cement composites with different fly ash contents, which led to the discovery that the fly ash cement composites showed strain rate dependency and maintained plastic flow during the impact process.…”