A Novel Approach to Delivering Superabsorbent Polymers for Internal Curing of Concrete

This study investigates feasibility of incorporating dry superabsorbent polymer (SAP) particles as internal curing agents in concrete utilizing two delivery methods: direct addition of the particles and addition of the particles encapsulated in dissolvable bags. The use of dissolvable bags provides a practical method of storing, handling, and dosing pre-measured amounts of dry SAP particles into cementitious mixtures. Concrete specimens containing SAPs were prepared using both methods, and their properties were evaluated through compressive strength tests at 3, 7, and 28 days, flexural strength tests, ultrasonic pulse velocity (UPV) measurements, and dynamic elastic and shear modulus determinations. Results indicate that the use of dissolvable bag method led to improved mechanical properties and reduced variability compared to direct pouring, likely due to more uniform dispersion of SAP particles. Compressive and flexural strengths showed aignificant improvements, especially at early ages. UPV results confirmed higher uniformity of microstructure, while dynamic elastic and shear moduli indicated improved stiffness. The findings highlight the effectiveness of dissolvable bags delivery method as a practical and efficient approach that can be easily adopted for commercial applications.