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Cement-based materials prepared with activated water induced by a magnetic field or electric field represent a possible solution to environmental issues caused by the worldwide utilization of chemical admixtures. In this contribution, electric- and magnetic-activated water have been produced. The workability and mechanical properties of cement mortar prepared with this activated water have been investigated. The results indicate that the pH and absorbance (Abs) values of the water varied as the electric and magnetic field changed, and their values increased significantly, exhibiting improved activity compared with that of the untreated water. In addition, activated water still retains activity within 30 min of the resting time. The fluidity of the cement paste prepared with electric-activated water was significantly larger than that of the untreated paste. However, the level of improvement differed with the worst performance resulting from cement paste prepared with alternating voltage activated water. In terms of mechanical properties, both compressive strength and flexural strength obtained its maximum values at 280 mT with two processing cycles. The compressive strength increased 26% as the curing time increased from 7 days to 28 days and flexural strength increased by 31%. In addition, through the introduction of magnetic-activated water into cement mortar, the mechanical strength can be maintained without losing its workability when the amount of cement is reduced.

This article makes a study of electrochemical noise analysis on the crevice corrosion behavior of Ni-CrMo-V high strength steel using recurrence plots. The crevice corrosion behavior of Ni-Cr-Mo-V high strength steel was investigated by the electrochemical noise (EN) technique and SEM observation. The experimental results reveal that the crevice corrosion could be distinguished by three stages including induction stage, transformation stage, and stable stage. While increasing the growth probability of metastable corrosion, the presence of crevice decreases the initiation rate of metastable corrosion. In the case of crevice, the metastable corrosion is easy to develop into stable one.

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