An Experimental Study on Internal Curing of Concrete with the Inclusion of Recycled Superabsorbent Polymer (SAP)

Concrete, as a widely used construction material, is prone to various issues such as early-age shrinkage, cracking, and reduced durability. Internal curing, a technique aimed at providing a continuous source of moisture within the concrete matrix, has come to light as a possible approach for above mentioned issues. This study investigates the utilization of hydrogel (as a recycled form of SAP) derived from ice gel packs as an Internal Curing Agent (ICA) in concrete. Ice gel packs, commonly used for cold therapy (in many industries such as the medical field, cold storage, etc) contain Superabsorbent Polymers (SAPs) that can absorb and release moisture. By repurposing these gel packs, this study explores the feasibility and effectiveness of the hydrogel in internal curing, evaluating its impact on workability, strength development, water absorption, and its optimal amount/ dosage (i.e. percentage replacement of cement) etc. This study also investigates the mix design considerations, and potential challenges associated with incorporating hydrogel into concrete. The findings show that the mechanical properties were improved i.e. compressive, split tensile, and flexural strength at 28 days were increased by 9.83%, 8.94%, and 17.52% respectively. Also, the optimum amount used for SAP was identified as 0.7% (which is percentage replacement of cement). These findings contribute to advancing knowledge on the use of ice gel pack-derived hydrogel for internal curing, paving the way for more sustainable and durable concrete structures.