Cracked Concrete Lintel

[PSUengineer1]

Please see attached photo. I have a cracked lintel. The cracking is about 1/16 inch wide and is horizontal across the lintel's length (at about mid-height). Lintel span is about 5 feet. Stucco above is not cracked. The lintel supports CMU above. This is an early 1900s house with exterior walls built of CMUs. I think the cracks are from long-term exposure to moisture, in this case the elements. No evidence of water intrusion through roof or down from the window above. Concrete is porous and moisture gets trapped, and with temperature variations over the long-term, the trapped moisture causes the concrete to crack. Reinforcement (if any in the lintel) could rust from the water intrusion.

I am looking for your thoughts on what the crack is from. Thank you.

 

[BAretired]

It looks like rusting rebar expanded and cracked the concrete.

BA

 

[dik]

Rebar that high?

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[XR250]

I agree with BA.

 

[LittleWheels]

No visible rust staining but but my first guess would be corroded rebar spalling off the corner of the cross-section.