“Comparative Analysis of Polyethylene Glycol and Super Absorbent Polymers as Internal Curing Agents in M40 Structural Concrete”

1.      Internal curing using PEG-400 and SAP is technically feasible in M40 grade structural concrete without loss of workability, both mixes achieving slump values within the design range at 1% and 2% dosage. 2.      Within the dosage range examined (1% and 2% by weight of cement), neither PEG-400 nor SAP enhanced compressive, split tensile or flexural strength relative to the conventionally cured control mix; both agents instead produced a measurable strength reduction that increased with dosage. 3.        PEG-400 is the more strength-efficient of the two internal curing agents examined, consistently outperforming SAP in compressive, split tensile and flexural strength at every curing age and dosage tested. 4.       A dosage of 1% PEG-400 by weight of cement is identified as the more favourable of the two dosages examined, offering the closest strength match to conventional curing among the internally cured mixes. 5.     SAP at 1% dosage remains a workable internal curing option where PEG-400 is unavailable, though it carries a larger compressive strength penalty (approximately 13% at 28 days) than PEG-400 (approximately 5% at 28 days) relative to the control mix. 6.      The strength gap between PEG-400 and SAP narrows with curing age for tensile and flexural properties, indicating that the internal moisture reserve provided by both agents continues to support hydration beyond 7 days. 7.      The comparative strength penalty associated with SAP is attributed principally to residual micro-voids left after water release, whereas PEG-400 supports hydration through a water-retentive film without introducing an equivalent void structure. 8.      From a sustainability perspective, both agents reduce reliance on continuous external water curing, which is of practical value in water-scarce regions or on sites where consistent water curing is difficult to enforce, provided the associated strength trade-off is accounted for in design. 9.      For M40 structural applications where mechanical strength is the governing criterion, PEG-400 at 1% by weight of cement is recommended as the more practical internal curing agent among those evaluated in this study.

1.          Mangal P, Juremalani J. Comparative study of self-curing concrete using lightweight aggregates and hydrogel (SAP) as internal curing agents. 2026. 2.        Virupakshappa SG, Basappa AS, Thimmarayappa M, Narayana CKN, Buradi A, Emma AF. Modelling and analysis of strength and durability properties of internal curing concrete using PEG-400. 2024. 3.         Zhou B, Wang K, Taylor PC, Gu Y. Superabsorbent polymers for internal curing concrete: an additional review on characteristics, effects, and applications. 2024. 4.         Jindal A, Mehra D. An experimental study on internal curing of concrete with the inclusion of recycled superabsorbent polymer (SAP). 2024. 5.         Ganesan S, Palaniappan M. Study on the effectiveness of SAP, PEG-400 and PVA as self-curing agents: a comparative approach. 2026. 6.          Jaishankar P, Kanchidurai S, Vivek SS, Venkatasubramanian C, Muthu D. Performance of self-curing concrete with addition of polyethylene glycol 400 and super absorbent polymer. E3S Web Conf. 2025;559. 7.         Ganesan S, Palaniappan M. Optimal dosage arrival of polyethylene glycol-400 in achieving self-curing concrete: an experimental strength and durability study. 2025. 8.         Hamzah N, Saman HM, Baghban MH, Sam ARM, Faridmehr I, Sidek MNM, et al. A review on the use of self-curing agents and its mechanism in high-performance cementitious materials. 2022. 9.         Mousa MI, Mahdy MG, Abdel-Reheem AH, Yehia AZ. Self-curing concrete types; water retention and durability. 2015. 10.          Batikha M, Jotangia R, Baaj MY, Mousleh I. 3D concrete printing for sustainable and economical construction: a comparative study. 2022.