The fourth: "Cut" mud-known life of this step to cement mainly used fingers to "pulse" cement density, to identify its factory length of time. Cement also has the shelf life of cement, in general, more than 30 days of the date of manufacture of cement strength will decline. Cement its strength after storage for three months decreased by 10% to 20% after one year decreased by 25% -40%. Proper use of cement should be no damp agglomeration, high-quality cement with a finger twist cement powder, feel the feeling of fine particles. Cement, opening check the packaging of poor quality will be damp and agglomeration; inferior cement cement powder with your fingers twist, a rough sense, indicating that the cement fineness coarse, irregular, time use low strength concrete tile, sticky poor . If the cement contains too much free calcium oxide or magnesium oxide, especially coarse particles, and when the plant has a shorter storage time, it will have stability unacceptable phenomenon. Because this fire (1000 ℃ above) calcium oxide and magnesium oxide is not completely been fully cooked, very slow white cement hydration itself, after cement setting that is under constrained conditions began to cement hydration, resulting in volume expansion After, it will form a crack. In addition, if too much cement content of sulfur trioxide, generates sulphoaluminate, volume expansion, will also adversely stability. Cement mortar, caidian cement, cement supplied by Wuhan Hongshan District of Wuhan pavilion cement operation. Hongshan District of Wuhan pavilion cement business unit (www.whltsn.com) (www.hbltsn.com) strong, credible, in Wuhan of cement and related products industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Wuhan cement into the brilliant and you work for a better future!