Research on the shrinkage performance and pore characteristics of flexible solidified silt based on solid waste

This study aimed to verify the effect of solidification materials based on solid waste on the shrink-age performance of silt, the main raw materials of solid waste were red mud, zeolite powder, and matrix asphalt. Temperature shrinkage and drying shrinkage tests were conducted to compare and analyze the shrinkage characteristics using three kinds of solidification materials (2%, 4%, and 6%), with 6% cement-solidified soil and plain soil used as control. The results showed that the solidification material based on solid waste effectively reduced the temperature shrinkage strain and temperature shrinkage coefficient of soil; moreover, the material had good resistance to temperature shrinkage deformation. A drying shrinkage test showed that the addition of solidification materials based on solid waste considerably improved the early water retention capacity of the test soil. The water loss process mainly occurred in the first 7 days of the test. Meanwhile, the addition of the solidification material considerably reduced the drying shrinkage strain and drying shrinkage coefficient of the test soil, and the effect was more obvious as the content amount increased. Through NMR and CT scanning tests, the pore size and pore volume of the solidified material mixed with solid waste were found to be significantly reduced. The dominant pore size ranged from 0.01 μm to 1 μm. The solidification material based on solid waste improved the crack resistance of the soil, providing a new reference measure for subgrade and roadbed fillers, as well as a new means for the recycling of solid waste.