Strength Properties and Microscopic Experimental Study of Modified Sawdust Based on Solid Waste Synergistic Utilization

Sawdust is the cutting tailings produced during stone processing, which is difficult to deal with and has a huge stock. Therefore, it is particularly important to enhance the comprehensive utilization of sawdust. The aim of this study was to synergistically utilize sawdust with other industrial wastes (fly ash, silt, and red mud), add cement as a curing agent to prepare modified sawdust, and analyze its performance through an unconfined compressive strength test, dry and wet cycle tests, and SEM. The results showed that the compressive strength of modified sawdust with different solid waste dosages was more than 2.5 MPa after 7 days of maintenance, the strength was basically more than 4 MPa after 28 days of maintenance, and 8% solid waste dosage had the best effect. In addition, the modified saw mud with 8% fly-ash dosage had superior wet and dry cycle resistance, with expansion and shrinkage lower than 0.5% and good stability. This study provides a new idea for the synergistic utilization of saw mud and other solid wastes, and it is recommended to consider 8% solid waste dosage to optimize the performance in practical applications.