Glutinous rice paste stabilizes earthen site soil with environmental benefits

Earthen sites deteriorate under long-term environmental exposure, requiring compatible and low-carbon stabilization strategies. This study evaluated glutinous rice paste (GRP) as a stabilizer for authentic soil from the Tongwan city site. Samples were treated with 0, 5.0, 7.5, and 10.0 wt% GRP and examined using direct shear, consolidation, SEM, X-ray CT, and life cycle assessment. The optimal consistency was 7.5 wt%, which increased cohesion by 70.3% and reduced compressibility by 27.5%; 5.0 wt% produced limited strengthening, whereas 10.0 wt% increased compressibility. SEM and CT analyses showed that GRP formed a gelatinized polysaccharide network that coated and bonded soil particles, refined pores, and reduced pore connectivity and orientation. Compared with potassium silicate and lime-polypropylene fiber stabilization, GRP reduced global warming potential by 57% and 90%, respectively. Overall, GRP provides a mechanically effective and environmentally friendly option for the low-carbon conservation of earthen site soils.