Abstract: In the aim of environmental protection and promoting the utilization of industrial by-products, we conducted one-dimensional consolidation and scanning electron microscope (SEM) tests on cement solidified soil mixed with industrial by-products such as ground granulated blast-furnace slag, fly ash, and calcium carbide slag. We examined the microscopic mechanism of industrial by-products' type, content, and curing age affecting the compressibility behavior of cement solidified soil. Results demonstrated a significantly positive effect of industrial by-products on the compressibility behavior of cement solidified soil. As the content of industrial by-products increased, the void ratio and compression amount of solidified soil gradually decreased, while the yield stress increased. Moreover, the compressibility of soil solidified by cement with calcium carbide slag increased with higher content, whereas the compressibility of soil solidified by cement with fly ash and ground granulated blast-furnace slag initially increased and then decreased. The optimum content varied dependent on the type of industrial by-products. SEM test revealed that the improvement in compressibility can be attributed to cementation and filling effects. Additionally, we established a prediction model of compression amount based on the bounded function to offer reference for future construction and research.

Key words: industrial by-products, solidification, compressibility behavior, yield stress, prediction model