Abstract:

This study investigated the effects of magnetized water on the workability and compressive strength of concrete at four strength grades （C20， C40， C60， and C80）， using mixing water subjected to different magnetization cycles （1， 5 or 10 times） under fixed magnetic field intensity （1 T） and flow velocity （1.33 m/s）. Microstructural changes were characterized using scanning electron microscopy （SEM） and mercury intrusion porosimetry （MIP）. The results indicate that magnetized water significantly enhances concrete workability. Among the four grades， C60 concrete shows the most pronounced improvement， with slump increasing by 41.17% and flow spread by 20.27%. Regarding mechanical properties， C40 concrete exhibits the greatest gains in compressive strength， achieving increases of 16.81%， 18.37%， and 10.22% at 3， 7， and 28 d， respectively. The optimal performance is achieved at five magnetization cycles. Microstructural analysis reveals that magnetized water promotes cement hydration， leading to increased C-S-H gel formation， denser paste structure， and refined pore size distribution. These findings provide insights into the role of magnetization cycles in modulating concrete performance and support the application of magnetized water in sustainable concrete construction.

Key words: magnetized water, concrete, workability, compressive strength, microstructure, pore structure