1. The cement paper bags are well packed and fully labeled.

The markings on the paper bag include: factory name, production license number, cement name, registered trademark, variety (including variety code), label, packaging year, month, day and serial number.

Different types of cement are marked with different colors. Portland cement and ordinary Portland cement are marked in red, slag cement is green, and pozzolan cement and fly ash cement are black.

2. Twist the cement powder with your fingers. If you feel it has a slightly fine, sandy, and powdery feel, it indicates that the cement fineness is normal.

3. Observe that the color is dark gray or dark green, and the cement strength is relatively low if the color is yellow or white (yellow color indicates that the clinker is raw material and the whitish slag content is too much) .

4. No moisture agglomeration.

Be sure to see clearly the production date of the cement.

Cement also has a service life, and the performance of cement that exceeds the validity period of 30 days has declined.

The strength of cement will drop by 10-20 after three months of storage, by 15-30 after six months, and by 25-40 after one year.

High-quality cement can solidify in more than 6 hours.

Cement that cannot set for more than 12 hours is of poor quality.

5. It is necessary to correctly select the cement grade and the mixing ratio of cement and sand.

The proportion of cement is large, and the adhesion of ceramic tiles is strong, and the bricks can stick quickly. However, the mixing proportion of cement is high, and the expansion coefficient of cement mortar is large, so it is easy to squeeze and crack the bricks after paving.

The recommended ratio is 1:3 for wall tiles, 1:2--3 for floor tiles, and the cement label is No. 325 cement.

6. When using cement, you must pay attention to the marking. The marking indicates the strength of the cement.

There are several types of ordinary cement such as 75, 325, 425, 525, 625, 725R, etc.

The larger the number, the better the compressive and tensile strength.

Generally, No. 25 cement can be used for indoor decoration. However, it is best not to exceed the 425 grade of cement for wall and floor tiles. The higher the grade, the greater the expansion of the cement, which can easily cause hollowing of floor tiles and wall tiles. Bricks tear or simply fall off.

7. Cement cannot be used if it is 3 months beyond the factory date. Cement of different brands and labels cannot be mixed.