The early viscoelastic properties of OPC-based materials, such as concrete, are significantly influenced by the reactions involving tricalcium aluminate (C 3 A) . In the first minutes of hydration, the reaction of C 3 A, which typically constitutes up to 10 wt.% of OPC , with water leads to the precipitation of calcium-aluminate-hydrates (C-A-H, AFm phases). If not adequately controlled, this process results in a swift decline in workability. This phenomenon, known as a flash set, is attributed to the formation of AFm phases (C 2 AH 8 and C 4 AH 13 ), which form as platelets, causing rapid stiffening of the paste .