Enhancement of the energy dissipation capacity C-S-H gel through self-crosslinking the poly (vinyl alcohol)

Damping cementitious materials have been widely used in engineering structures for vibration control. However, achieving a balance between the mechanical strength and damping capacity of cementitious materials remains a challenge. Herein, we utilized an initiator (APS) to initiate the self-crosslinking reaction of PVA molecules in C₃S paste, then successfully introduced the viscoelastic PVA membranes into C-S-H gel to enhance its energy dissipation capacity. Results showed that the self-crosslinking PVA (scPVA) increased the loss modulus ($E^{\prime \prime }$) of C-S-H gel by about 158 %, increased loss tangent ($tan\delta$) by 85 % and increased the compressive strength by 24 %. Nano-microscopic tests and molecular dynamics (MD) simulation confirmed that scPVA was introduced into C-S-H gel via the hydrogen-bonding interaction, and then formed the viscoelastic PVA membranes, which promoted C₃S hydration, reduced the pore size of C-S-H gel and increased the mean chain length (MCL) of C-S-H gel. This study proposes a novel approach for designing high-damping cementitious materials.