Teach you the difference between good and bad cement

Cement is one of the indispensable materials for every home decoration。Therefore, when we choose cement, we must choose a good cement, so that we can save a lot of worries, bring us convenience, then how to judge the quality of cement?After the analysis of experts, here the small edition of south wind building materials will teach you this method!Keep an eye out!

　　① The paper bag of cement is in good condition and the mark is complete。

　　The identification on the paper bag is: factory name, production license number, cement name, registered trademark, variety (including variety code), label, packaging year, month, day and number。Different types of cement are identified in different colors, red for Portland cement and ordinary Portland cement, green for slag cement, and black for pozzolanic and fly ash cement。

　　② Twist cement powder with fingers, feel a little fine, sand, powder feeling, indicating that the cement fineness is normal。

　　③ Observe that the color is dark gray or dark green, and the color is yellow and white (yellow indicates that the clinker is raw sintering and the amount of white slag is too much) of the cement strength is relatively low。

　　④ no moisture caking phenomenon。Make sure you look at the date the cement was made。Cement also has an expiration date, and the properties of cement beyond the expiration date of 30 days are degraded。After three months of storage, cement loses 10% of its strength?20% and 15% lower after six months?30% and 25% less after a year?40%。High quality cement, more than 6 hours to set。Cement that does not set for more than 12 hours is of poor quality。