Internal Curing of Self-Compacting Concrete Using Superabsorbent Polymers Based on Sodium and potassium

One Of the effective parameters in the final strength and durability of self-compacting concrete is post-fabrication curing. External Curing with water Supply and moisture retaining coating are commonly used despite the limitation of these methods. Internal curing is one of the main issues in the implementation of reinforced concrete and bulk concrete structures with much less restrictions, especially in high performance concrete. The aim of this study was to investigate the effect of internal curing of self-compacting concrete using superabsorbent polymers on mechanical properties and durability of concrete. These polymers absorb some water and gradually release it during the hydration process. Using this method, the curing process is performed more efficiently, not only on the surface but also in the depth of concrete elements. Two types of superabsorbent polymer powders based on sodium and potassium with two different amounts have been used in this research. Concrete samples at 7 and 28 days of age were subjected to compressive strength, electrical resistance, water permeability, thaw-freeze cycle and microstructure tests including SEM, XRD and XRF. Compressive strength of samples with internal curing increased by 11.4% compared to control samples. In terms of durability parameters, the samples with internal curing show a reduction of more than 100% in water permeability and 16.7% improvement in electrical resistance. The result of microstructural experiments showed an improvement in evolution of the hydration process by at least 2.4% and at most 8.3% due to internal curing.