The early strength of early strength cement is higher than that of ordinary cement without R.

The strength grade of cement is a sign of cement strength, and the measuring index is the compressive strength of cement. The testing standard is mainly the strength of cement mortar after 28 days of hardening. For example, after 28 days, the compressive strength is 42.5MPa, and the cement strength grade is 42.5 or 42.5 R. ..

Cement has eight strength grades: 32.5, 32.5R, 42.5, 42.5R, 52.5, 52.5R, 62.5R, and some buildings can use the strength grades of 32.5 and 32.5r.. Strength grade above 42.5 can be used for building larger bridges or factories, as well as some important pavements and manufacturing prefabricated components.

In fact, the use of cement strength grade is not very detailed. Generally speaking, it will be clearly stipulated in the design drawings.

In civil construction projects, ordinary portland cement and slag portland cement are commonly used. The commonly used strength grades are P.O 42.5 and P.S 32.5/42.5.

Extended data

international standard

The European cement trial standard ENV 197- 1-95 divides the strength grades of ordinary cement into 32.5, 32.5R, 42.5, 42.5R, 52.5 and 52.5R；;

British Portland cement standard BS 12-9 1 divides the strength grades into 32.5, 32.5R, 42.5, 42.5R, 52.5 and 62.5. The strength test method adopted in the above two standards is ES 196 equivalent to ISO679.

However, China's cement label is formulated through the ENV 197- 1-95 standard, BS 12-9 1 standard and China's development status.

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