Durability and Compressive Strength, Low Tests 3

[Boiler106]

With respect to ACI 318-14, our compressive strength tests for a retaining wall fall marginally below the minimum f’c requirements for durability given in Table 19.3.2.1 for Exposure Class F2, but our analysis indicates the lower concrete strengths are acceptable for the applied forces. The difference in value is 200 psi, however, the arithmetic mean of the tests does not equal or exceed f’c.

Does the concrete need to meet the strength requirements of 26.12.3.1 Compliance Requirements and 26.12.4 Investigation of low strength-test results for durability even though its adequate for the applied forces? Or are there relaxed requirements for durability alone?

If not, are there other solutions such as applying xypex?

 

[dik]

There was an issue with that a while back in Winnipeg or Toronto, I'm not sure where I was. There waS a huge demand for cement and the degree of fineness to the cement powder wasn't up to snuff...

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

-Dik

 

[dik]

For durability/serviceability I generally don't use anything other than 28days. I have a rough idea of how 28day strength behaves... not 56day strength. I think it's an error to look at it in that fashion.

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

-Dik

 

[JLNJ]

Where is your exact location and what is the nature of the retaining wall? Maybe you can justify a little lower exposure class. In fact, the exposure classes themselves are not very granular. ACI assigns exposure class with an axe and you might be trying to measure the resulting log with a micrometer.

 

[JoelTXCive]

I just noticed that last month's Concrete International Magazine had an article on Low Breaks and next steps to take.... See attached...

 

[MHobbs]

Generally using 56-day strength rather than 28 can be a great way to take cement out of the concrete mix reducing cost and environmental burden. It won't be suitable for all construction practices but if the scheduling of construction can accommodate the concrete reaching the final design strength later it's something worth considering.

https://www.greenspec.co.uk/buildin...ete,CEM II/CEM III or an addition. More items