Abstract
Adding magnesia can compensate shrinkage of concrete and prevent crack of concrete, and this technique is applied widely. However, if magnitude of expansive stress caused by adscititious magnesia is too large, it trends to damage the structure of cement concrete. Substantial research results show that the magnetized water can make the cement hydration reaction more completely. The magnetic water can increase the strength of concrete, which can infer that the impermeability of concrete has been improved. So, the physical and chemical properties of magnetized water in different degrees and the compactness and impermeability of the magnesium oxide micro-expanded concrete mixed with magnetized water in different degrees are studied in the thesis. The research starts with the physical and chemical properties of magnetized water such as the conductivity, viscosity, PH value and surface tension. 14 samples with the intensity levels C25 and C30 MgO concrete are chosen in the impermeability test. The test indicates the difference of impermeability between magnetized water MgO concrete and ordinary water MgO concrete at the condition of same strength. The effects such as hypothesis of the mechanism, action of the cement hydration, concrete workability, water ratio of the concrete of MgO concrete mixed with magnetic water was studied in this issue. And the mechanism of impermeability of magnetic water MgO concrete is also analysed.
