Probing the hydration behavior of tricalcium aluminate under the in situ polymerization of acrylic acid

The early hydration of Portland cement is profoundly affected by the mineral phase of tricalcium aluminate (C3A), but how in situ polymerization of monomers influences the hydration of C3A remains unclear. Herein, we probed the effect of in situ polymerization of acrylic acid (AA) on the hydration behavior of cubic C3A from experiment and ab initio molecular dynamics simulation (AIMD). Our findings reveal that in situ polymerization of AA retarded C3A hydration, which was corroborated by the AIMD result that polyacrylic acid (PAA) reduced the charge transfer between C3A and water and inhibited the dissolution of Ca ions from C3A surfaces by adsorbing on the C3A. Additionally, in situ polymerized PAA improves the carbonation resistance of C3A hydrates, accompanied by lowering their crystallinity. Hopefully, our findings can provide valuable guidance on the theory for implementing in situ polymerization of monomers in cement-based materials.