Strength Development and Stabilization Mechanism of Water-Based Drilling Cuttings Treated with a Multi-Source Solid-Waste Binder

Water-based drilling cuttings (WBDCs) are a large-volume solid waste generated during oil and gas drilling. Their weak cementation and loose particle structure limit their direct engineering utilization. In this study, a multi-source solid-waste binder mainly composed of ground granulated blast furnace slag (GGBS) and fly ash (FA) was used to stabilize WBDCs. Portland cement was used as an auxiliary binder, and sodium silicate was used as the alkaline activator. The effects of sodium silicate modulus, sodium silicate dosage, cement dosage, and GGBS-to-FA mass ratio on strength development were investigated. XRD, FTIR, TG, MIP, and SEM-EDS were further employed to clarify the stabilization mechanism. The results showed that binder composition strongly affected the strength level and strength development rate of stabilized WBDCs. At a total binder dosage of 15%, the mixture with a sodium silicate modulus of 1.4, a sodium silicate dosage of 4%, a cement dosage of 10%, and a GGBS-to-FA mass ratio of 6:1 exhibited the best mechanical performance. Its unconfined compressive strengths reached 6.87, 9.74, and 10.17 MPa at 7, 14, and 28 d, respectively. Microstructural analyses indicated that the strength development of stabilized WBDCs was mainly associated with the formation and continued development of poorly crystalline C-S-H/C-(A)-S-H-type gels and a small amount of AFt. From 7 to 28 d, the porosity and total pore volume decreased by 9.5% and 11.0%, respectively, while the average pore diameter decreased by 31.2%. This study provides a basis for the resource utilization of WBDCs and the design of low-cement binders containing multiple industrial solid wastes.