Zhu H.-B.,Tongji University |
Wang P.-M.,Tongji University |
Zhang J.-D.,Pangang Group Co. |
Wang B.-W.,Armed Police Force College
Jianzhu Cailiao Xuebao/Journal of Building Materials | Year: 2011
Pangang chlorination titanium blast furnace slag fume(TZ) contains higher mass of TiO2 and chloride ions. It is liable to be affected with damp. Because particle size of TZ is high and TiO2 can react with CaO to form ilmenite, TZ exhibits poor pozzolana activity. After being washed, dried and ground, chloride ion content(by mass) of TZ can reduce from 3.14% to 0.45%. Steel corrosion in concrete caused by chloride can be avoided. Meanwhile, pozzolana reactivity of TZ increases. If 50% of cement is replaced by the same mass of ground TZ to prepare mortar, the pozzolana activity index can be improved from 36% to 68%. If 30% of cement is replaced by the same mass of ground TZ, the pozzolana activity index is 84%. The pozzolana activity of ground TZ is lower than that of S95 grade of blast furnace ground slag, and is higher than that of II grade of fly ash. Ground TZ can improve microscopic structure of hardened cement. It can decrease the directional tendency of hydration product CH of cement, and can reduce the CH crystal size. Therefore the disadvantageous interfaces between CH crystal and other hydration products losses. It is favorable for durability of concrete.