The strength grades of ordinary portland cement in life are divided into four grades: 42.5, 42.5R, 52.5 and 52.5r. The strength grades of slag portland cement, pozzolanic portland cement, fly ash portland cement and composite portland cement are divided into six grades: 32.5, 32.5R, 42.5, 42.5R, 52.5r and 52.5r..
Cement label includes the strength of cement after solidification, and the strength of cement label includes the tensile strength and compressive strength of cement after solidification. The higher the cement grade, the greater the cement strength, and vice versa.
The cement label also includes the setting speed of cement. Generally, in emergency projects such as underwater engineering, such as building piers and sewers, cement setting time is required to be short.
Generally, quick-hardening cement with cement number 700 and 800 is better. For building projects such as walls and floors, if the setting time of cement is not too high, you can choose cement with slow setting time.
Extended data
Precautions:
When choosing cement, you should choose it according to different cement uses. The application scope of each cement label is different. For example, cement 525 has fast drying speed and high strength.
However, in the hot, hot and summer environment, if the wall is built with 525 cement, it is easy to crack, so this 525 cement is generally used to pave the floor. In addition, not all masonry walls are stressed walls, and ordinary 425 cement or 325 cement can meet the requirements of early construction.