Concrete Cracking Stress vs. Fatigue

[JAE]

In the ACI, there is the value given for modulus of rupture, fr = 7.5 x sqrt(f'c). This is the theoretical stress at which normal weight concrete will crack. For 4000 psi concrete this is about 474 psi.

My question is this. When concrete is stressed to something less than that value, whether it be 100 psi or 300 psi, it isn't supposed to crack. But if that concrete is subjected to repetitions of stress at these lower values, does the concrete fatigue (like steel) and crack at the lower stress levels after so many cycles?

If so, is there any documentation of this anywhere that would suggest acceptable stress levels with repeated loading? Like the AISC fatigue tables for steel stress ranges?

 

[magudfe]

Maybe you can check this article "Fatigue of normal weight concrete and lightweight concrete"

http://www.sintef.no/static/BM/projects/EuroLightCon/BE3942R34.pdf

In paragraph 4.3.3 you can find a reference to Model Code 1990, regarding the failure of concrete subjected to fatigue load under tension. The failure will not occur if a certain limitation is satisfied. For a concrete of 4000psi (27.6MPa) it gives a maximum value of stress of 60psi (including a material coefficient of 1.5).

 

[JAE]

Thanks, magudfe, looks interesting and relevent to my question - I'll look at it.