Abstract:
Using mineral-based cementitious material as a curing agent and aluminum powder paste as a foaming agent, light-weight solidified soil dredged marine silt were prepared by in-situ foaming method. The influence law of curing agent content (1∶10−1∶4), foaming agent content (0.025%−0.100%), and water-to-binder ratio (0.6−1.2) on the unconfined compressive strength (UCS), bulk density, water absorption, softening coefficient of the samples were systematically investigated. The microstructural evolution and solidification mechanism were analyzed with X ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results show that increasing the curing agent content promotes the gas-generating reaction of aluminum powder, forming a more developed pore structure. This achieves a reduction in the bulk density to 0.75 t/m
3 while improving the UCS to 1.06 MPa. However, higher foaming agent content and water-to-binder ratio led to a simultaneous decrease in both bulk density and UCS. Under the optimal mix proportion (curing agent content of 1∶4, foaming agent content of 0.100%, and water-to-binder ratio of 1.0), the 28 d sample exhibits excellent comprehensive performance, with a UCS of 1.06 MPa, bulk density of 0.75 t/m
3, and softening coefficient of 0.84.The enhanced performance is attributed to the formation of a network structure composed of hydration products such as calcium silicate hydrate (C—S—H) and ettringite (AFt), which effectively bonds particles while regulating pore distribution, thereby achieving a synergistic optimization of lightweight characteristics and mechanical properties. This study provides important insights for the development of soft soil stabilization materials in land reclamation engineering.