Can superabsorbent polymers be used as rheology modifiers for cementitious materials in the context of 3D concrete printing?

Autogenous shrinkage may be a critical issue concerning the use of limestone-calcined clay-cement (LC3) in high-performance concrete and 3D printable cementitious materials, which have relatively low water to binder (W/B) ratio. Adding an internal curing agent, i.e., superabsorbent polymer (SAP), could viable solution this context. However, employing SAP (without adding additional water) also influence fresh properties LC3 composites by increasing yield stress viscosity, beneficial for printability. Therefore, study attempts as rheology modifying admixture with aim investigating impact on flow behavior, structural build-up, hydration kinetics, compressive strength, autogenous pastes fixed W/B (0.3). In addition, hydroxypropyl methylcellulose (a typical rheology/viscosity modifier materials) was employed two mixtures compare their effects. Results show that increases dynamic apparent well build-up hydration, but decreases strength at 3, 7 28 days. Furthermore, using (especially 0.2 wt% SAP) not only promotes early-age expansion effectively mitigates up Overall, obtained results indicated act promising development materials.