Study on the carbonation resistance of sulphoaluminate cement grouting materials enhanced by acrylamide in-situ polymerization modification

Sulphoaluminate cement (SAC) is widely used in grouting applications owing to its rapid setting and high early strength. However, its low resistance to carbonation in high-CO 2 environments restricts its broader application. This study explores the enhancement of SAC's carbonation resistance through in-situ polymerization of acrylamide (AM). SAC was modified with varying AM dosages (0–40%), and the carbonation depth, mechanical properties, and microstructure were evaluated after different carbonation periods. The results indicate that increasing the AM content significantly improved SAC's long-term carbonation resistance. Samples with ≥20% AM exhibited carbonation depths of less than 3 mm after 28 days of accelerated carbonation. Microstructural analysis revealed that in-situ polymerized PAM formed an interpenetrating organic-inorganic network with cement hydration products, enhancing both ductility and strength. The encapsulation of hydration products by PAM hindered CO 2 contact, while pore-filling effects reduced CO 2 diffusion pathways. This study demonstrates that in-situ polymerized PAM is a promising solution for mitigating carbonation-induced deterioration in SAC, potentially expanding its application in high CO 2 environments. • Toughening of cement by AM in situ polymerization. • In situ polymerization of AM in SAC improves the carbonation resistance of SAC. • Excellent durability with unique flexible-rigid interpenetrating structure.