Concrete Strenght from 1913

[Tinguindin]

Hey Guys;

I am working on a Pipe Support Design, I will be using Cable Pipe Hangers / Nylon Strap. The problem is that this is a 78" diameter concrete pipe that was built in 1913. I was able to find the plans, but no Concrete Strenght was specified. Any Ideas on the f'c?

Thanks


Regards

 

[Tinguindin]

Sorry, the title is Concrete Strength.

Regards

 

[Ron]

Assuming the pipe is still serviceable and there's little evidence of deterioration, my guess would be relatively high strength concrete, probably on the order of 5000 to 6000 psi. You can check it with a Windsor Probe and that will get you in the ballpark. Don't rely on a Swiss Hammer (rebound hammer) to give you an accurate strength value.

 

[Tinguindin]

Thanks Ron;

6000 psi seems very high, but I will take into consideration the Windsor Probe.

Here is a Picture of what I am talking about.

Regards

 

[dik]

I would have guessed about half that value. I've encountered concrete strengths from that time period of from 2000 to an upset of 3000, give or take. 1913 was in the early years of PCC use and early mixes were predicated on mortar mixes. A "three bag" or "two and a half bag" mix were not uncommon. These would yield approx 3000 psi concrete. A six or seven bag mix were not common.

Again it being during the earlier stages of PCC use, anything is possible.

 

[cvg]

you would be better off estimating low, especially since the condition and thickness of the concrete may be questionable and highly variable. Design life for concrete pipe or other structures is commonly estimated at 100 years so your pipe has reached the end of a long and happy life