Stabilization strategies for granite waste powder applied in sustainable pavement subgrade: Mechanical and durability performance

The sustainable and efficient treatment of massive granite waste powder (GWP) has received increasing attention. This study proposes a novel method for recycling GWP cemented by inorganic binder-stabilized materials (IBSM) for sustainable pavement subgrade filler, i.e., IBSM-stabilized GWP (ISG). IBSM consists of Portland cement (PC), quicklime (QL), ground granulated blast furnace slag (GGBS), and sodium dodecyl benzene sulfonate (SDBS). Response surface methodology (RSM) and microstructure analysis were employed to analyze the effects of IBSM components on ISG mechanical properties and durability. The 56d compressive strength of ISG is above 2.62 MPa, meeting the minimum criterion of 1 MPa. The residual strength coefficient after 5 freezing-drawing cycles is generally greater than 65 %, except for the groups with high QL content. Both PC and GGBS are positively correlated with the performance of ISG. Moreover, multi-objective optimization identifies the optimal mix ratio: 3.03 % PC, 0.83 % QL, 3.47 % GGBS, and 0.18 % SDBS. The optimal ISG presents excellent strength and durability performance, with S-7d of 1.61 MPa, S-56d of 3.88 MPa, S-w of 3.35 MPa, R-ftc of 90 %, R-wdc of 92.01 %. These findings provide insight into the stabilization strategies of GWP using in highway subgrade filler, which can alleviate the environmental pollution induced by GWP waste.