No abstract

To achieve better mechanical properties and higher scour resistance of yellow mud in Qiang Village, this study investigated how to improve yellow mud by single factors of straw, starch, cement, and epoxy resin. First, the effect of each material on the shear strength of yellow mud was analyzed through the direct shear test, and the effect of the respective material on the scour resistance of yellow mud was examined using a self-made spray device. Subsequently, combined with the results of the two experiments, the improvement effect of the material was comprehensively studied, and the optimal dosage of the respective material was determined. Lastly, an electron microscope was used to observe the microscopic morphology of the samples, and the improvement mechanism of each material was discussed from qualitative and quantitative perspectives. As revealed by the results, straw, starch, cement, and epoxy resin improved the shear strength and scour resistance of yellow mud. Peaks of straw, starch, and epoxy resin were found in their corresponding properties-dosage curves, corresponding to the optimal dosage in the experimental range. The corresponding performance curve of cement showed a unidirectional change, which was found with a significant improvement effect.

More than 2 billion people around the world still use raw earth architecture, in countries like Nepal, India, and Iran. In China, the proportion of people living in earthen structures rose to 36%, some of them in western Sichuan. Minority dwellings in western Sichuan, China, use local stone and yellow mud as building materials and have been used for thousands of years. Because yellow mud is a brittle material with poor mechanical properties, and because the region is prone to earthquakes, the walls are highly susceptible to damage under seismic action. To improve the mechanical properties of yellow mud, the yellow mud of Taoping Qiang Village in western Sichuan was studied and modified. Uniaxial compressive tests were conducted on the modified specimens, and the existing ontogenetic equations of raw soil-based materials were analyzed and optimized. Finally, we developed the constitutive models for yellow clay and modified yellow clay in the western Sichuan area, which can be used for different kinds of modified materials through the variation of parameters. The results show that the compressive strength of yellow clay is improved by adding the modified materials. The optimized constitutive model can better fit the test curves, which can provide a basis for theoretical calculations and seismic mitigation of minority residential structures in western Sichuan or similar structural systems.