The difference between 32.5 cement and 42.5 cement: different strengths, different uses, and different final setting times.
1. Different strengths
You can know the strength from the label. The larger the label, the higher the strength. Therefore, the strength of 42.5 cement is higher than that of 32.5 cement. New number 32.5 = old number 425, new number 42.5 = old number 525. 32.5 means that after the cement solidifies for 28 days, its strength is 32.5MPa, and so on. The internationally accepted cement labels are 32.5 and 42.5.
2. Different uses
32.5 cement is mainly used for home decoration. For example, waterproof mortar, plastering, brick paving and other materials will use 32.5 cement, while 42.5 cement is used Used in building walls, concrete pouring, etc.
3. The final setting time is different
The initial setting time of both is required to be more than 45 minutes, but the final setting time of 32.5 cement cannot be less than 600 hours, while the final setting time of 42.5 cement cannot be Below 390 minutes.
Precautions for selecting cement
1. Pay attention to packaging
When choosing cement products, they are all packaged and there are relevant signs on the packaging bags. , including name, brand, production license number, variety, packaging year, month and day, etc. At the same time, pay attention to the color, because the color of the logo on the packaging of different types of cement is also different, for example, Portland cement will use red Logo, slag cement will be marked in green.
2. Pay attention to the fineness
When choosing cement, or before using cement, it is best to twist the cement powder with your fingers a few times. If it feels fine and powdery, the fineness is normal. of cement.
3. Pay attention to the color
Cement is colored, usually gray or dark green. If the color is yellow or white, be cautious, as it is most likely slag. Add a larger amount, which will affect the strength of the cement.