Enhanced underwater toughness and tunable setting time of cement-based materials by acrylamide in-situ polymerization

Applications in underwater environments impose stringent requirements on the toughness and workability of cement-based materials. In this study, acrylamide in-situ polymerization was introduced to modify conventional underwater cementitious materials without the use of superplasticizers, and its effects on material performance were systematically investigated. Results indicate that before polymerization, the modified sample exhibited a 79.41% increase in flowability compared with the control group, demonstrating excellent grouting capacity. Once polymerization was triggered, rapid solidification occurred within 6 min. This makes it possible to control the setting time of cement. Furthermore, compared with the control group, the sample incorporating acrylamide and cellulose achieved a 99.79% increase in underwater flexural strength and a 318.62% increase in ultimate strain. The underwater bond strength with old mortar reached 5.25 MPa, highlighting the material’s potential for underwater repair applications. This work provides theoretical insights and experimental evidence for optimizing underwater cement-based materials.