Concrete Flexural Modulus

[dicksewerrat]

I am trying to find the Flex Modulus for 9,000 psi concrete. It seems that is not tested for on a regular basis. I have the Flex. strength as 1,600 psi. Any help would be appreciated. Thanks

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[Ron]

Dick...for higher strength concrete, the flexural strength does not necessarily follow the correlation for lower strengths. This is because the flexural strength is very sensitive to coarse aggregate size, moreso than tensile strength of the cement paste for higher strengths.

You're right...not much has been done for flexure comparisons with high strength concrete.

I would probably not bank on 1600 psi. Probably more in the 800-1000 psi range, assuming #57 stone or similar coarse aggregate.

 

[conceng]

Ron is definitely in the ball park. A couple of months ago we did a mix design trial batch for a 3000/450 psi compression/flexural requirement in 30-hours. That did 8500/825 at 28-days.

Greg

Greg

 

[dik]

Your flexural tensile strength would likely be 800 to 900 psi for 9000 psi concrete as noted by conceng. With hydraulic testing equipment, it should be a simple matter of creating a couple of 'beam' mold samples and testing them. As I recall, the Ec value is similar to the compressive Ec.

In addition to the aggregate size, the angularity of the aggregate has a significant impact on the flexural tensile strength.

Dik