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 highCO2 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 CO2 contact, while pore-filling effects reduced CO2 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 CO2 environments.