PSI - Issue 70

Surya Mouli R. et al. / Procedia Structural Integrity 70 (2025) 239–246

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tapioca starch (TS) mixes the minimum shrinkage value of 0.058 mm occurred at 1.25% dosage while the control group reached 0.081 mm. The internal curing mechanism of the gel substance achieved its effect by holding moisture inside the mixture while decreasing the material's natural drying process. Higher gel amounts applied to the samples seemed to disrupt the hydration process and matrix packing which caused a minor growth of shrinkage levels. The study demonstrated that the best shrinkage outcomes occurred at moderate amounts of internal curing agents (Krafcik et al., 2017; Craeye et al., 2018). 4.6 Saturated Water Absorption (SWA) test The test findings on SWA are depicted in Fig.7. The SWA measurements of the starch gel mix (CS and TS) proved to be lower than the control mix (CM) which demonstrates that starch gel enhances concrete water retention properties. Less water penetrated the material because the starch gel improved pore structure possibly through its contribution to create fewer large interconnected openings between pores. The addition of higher starch gel percentages from 0.5% to 2.0% led to additional reduction in water absorption values which mainly affected TS mixes. The gel demonstrates water retention properties within the matrix so it decreases bulk water absorption levels. The data demonstrates that higher starch gel addition levels result in decreased absorption which stands as evidence that starch gel enhances concrete durability and water resistance. The control mix absorption levels remained higher than TS mixtures since control concrete usually demonstrates these elevated absorption rates. The research demonstrates how starch gel shows promise as an efficient concrete enhancement material for lowering water absorption and enhancing material durability.

Fig.7. Saturated water absorption results

5. Conclusion The research examined the performance of starch gel solutions used within concrete as an internal curing compound. The workability and durability and strength of concrete increased following addition of CS and TS starch gels. The slump test results demonstrated declining values as the amount of starch gel increased because of better workability effects. The highest compressive strength together with split tensile strength and modulus of rupture was attained at 7 and 28 days through the use of 1.0% CS starch gel combined with 1.25% TS starch gel. The materials used a reduced quantity of water in comparison to the normal control mix (CM) indicating they became more resistant to moisture dampness. Starch gel concrete showed lower rates of drying shrinkage which points to better stability of concrete dimensions. Concrete mixes containing starch gels exhibited reduced saturated water absorption levels which led to denser concrete structures that demonstrated increased permeability resistance. The addition of starch gel to concrete revealed potential as an efficient sustainable approach for improving concrete properties by strengthening its properties as well as providing durability and better resistance to moisture.