Influence of Mixing-Water Magnetization Method on the Performance of Silica Fume Concrete

The aim of this study is to experimentally investigate the mechanical characteristics of concrete combining silica fume (SF) and magnetized water (MW). A total of nine concrete mixes were prepared and tested for workability, compressive strength, splitting tensile strength, and flexural strength. Ordinary tap water (TW) and MW that was prepared with five proposed different methods were utilized in the concrete mixes. The MW was prepared by passing TW through a permanent magnetic field (having intensities of 1.4 Tesla and/or 1.6 Tesla) for a different number of cycles, namely 100, 150, and 250 cycles. Water characteristics were analyzed after being magnetized using the proposed different methods and compared with the TW characteristics. Non-destructive concrete testing (ultrasonic pulse velocity, and Schmidt hammer) was also conducted to determine the effect of MW on the prediction of concrete compressive strength. Scanning electron microscopy (SEM) analysis and energy dispersive X-ray (EDX) analysis were carried out on the produced mixes. Regardless of the method utilized to prepare the MW, the results revealed a considerable improvement in concrete compressive strength, splitting tensile strength, and flexural strength by up to 80%, 98%, and 22%, respectively, when MW was prepared with 150 cycles. The best water magnetization method found in this study was the passing of water through magnetic fields of 1.6T then 1.4T intensities for 150 cycles. The ultrasonic pulse velocity test resulted in good prediction of the concrete compressive strength with overall error ranged between −12.6% and +5.8%. MW significantly improved the concrete microstructure and produced a denser structure in comparison to the control conventional concrete.