svr1954
4 posts
TimePosted 12/05/2009 09:56:06
svr1954 says

spec for cement type is OPC 42.5-R. 3200 softness

Can anyone clarify spec for the above grade and its use & application

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Michael Clark
312 posts
TimePosted 13/05/2009 09:31:19

Re: spec for cement type is OPC 42.5-R. 3200 softness

OPC means Ordinary Portland Cement. 42.5R is a strength class from the EN197 cement specification. 3200 softness is not something I am familiar with.

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Dr. Shah
2 posts
TimePosted 20/08/2009 06:23:45
Dr. Shah says

Re: spec for cement type is OPC 42.5-R. 3200 softness

Dear Dr. Micheal Clark,

I believe by 'softness' the author of the subject query means blain value of cement in cm2/g.

As you have rightly said 42.5 R is strength class from EN 197. To clarify it further for the author, 42.5 R is high early strength cement. 2 days strength of this cement is equal or greater than 20 N/mm2 and 28 days strength is equal to or greater than 42.5 N/mm2. So for softness or blain value is concerned, EN 197 does not specify this as requirement. Being performance oriented standard, if it is left to the manufacturer, if he gets desired strength by grinding the cement upto '3200' softness or else.This cement is utilized where high early strength is preference of the user.

Shah

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Davo
44 posts
TimePosted 27/08/2009 15:09:30
Davo says

Re: spec for cement type is OPC 42.5-R. 3200 softness

Dear svr 1954 

In 42.5R 

42.5 is 42.5 MPa or 433 kg/sm2 that means that the cement compressive stength after 28 days must be not less than 42.5 MPa (or 433 kg/sm2).

R is "Rapid", that means that the cement has early strength and as said Dr. Shah, the compressive strength of the cement is not less than 20 MPa.

OPC is Ordinary Portland Cement.

And 3200 is specific surface of the cement - 3200 sm2/g

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