Inventor: Assis. Prof. Dr. Zeena Khthair Abass/Department of civil engineering, College of engineering, University of Baghdad
One of the most important problems that threaten the durability of concrete is the internal attack of sulphate which found in the aggregates. Sand in Iraq contains a high percentage of low soluble calcium sulphate in water. New technology is adopted in this study for treatment using magnetic water by two intensities (5000 and 9000) Gauss where physical properties of water, such as surface tension and solubility has been changed. Laboratory experiments proved the efficiency of the technique in reducing the content of sulphate in sand; the intensity 9000 Gauss was better than the intensity of 5000 Gauss. The optimum amount of magnetized water needed for washing was also determined to obtain satisfied sand (as required by Iraqi standard number 45). Moreover, concrete mixtures were prepared with sand before and after treatment. The results revealed that the concrete containing sand treated with magnetized water showed an increase in compressive strength compared to the concrete containing the untreated sand. For example, concrete mixtures containing treated sand (SO3 = 0.25) showed an increase in compressive resistance of (7,14, 10,69 and 32.87)% for the age of (28, 90 and 180) days respectively compared to the concrete contained untreated sand (SO3 = 3.0).