Determination of the Optimal Percentages of PEG-400 in the Internal Curing of Concrete: A Systematic Review

Abstract

Abstract- In situations where water resources are scarce, the optimization of internal curing in concrete has drawn more attention as a sustainable substitute for traditional external water curing. In order to assess the efficacy of polyethylene glycol (PEG-400) as an internal curing agent and identify the ideal dosage, this study presents a systematic review of the scientific literature published between 2017 and 2025. Using Scopus, Web of Science, ScienceDirect, and Google Scholar as the main databases, the review was carried out in accordance with the PRISMA methodology. Based on concrete grade, PEG-400 dosage, curing age, and mechanical performance, a total of 24 experimental investigations that satisfied the inclusion criteria were examined. The findings show that for M20, M30, and M40 concretes, a dose of 1% by weight of cement is the most frequently recorded and offers the highest overall performance in terms of compressive strength, reaching compressive strengths of up to 57.8 N/mm2 at 28 days. Higher dosages (1.5%–2%) may provide localized increases in tensile and flexural strength, but they may have a detrimental impact on workability and may not always improve compressive strength. All things considered, a 1% PEG-400 dosage is found to be the ideal worldwide ratio for efficient internal curing, guaranteeing ongoing hydration, enhanced mechanical performance, and decreased dependence on external curing water.