Cracked New Concrete

[Lazy Eric]

As said above , wait till you actually have a problem before spending again. You may get 25 years plus service life..
I also believe concrete ain’t what it was 30- 40 years ago..

 

[David.]

Some firms down here are using recycled aggregate now, and mixing sand and stone together, whereas they used to use ballast in the past, it doesn't tamp the same as it did.

 

[shumungus]

The latest thinking round here on silo floors is to lay 50N reinforced 150mm deep roughly tamped finish on base with starter bars for walls. Then when walls poured and finished lay floor with 70mm of 20N mix powerfloated glass hard. Thinking being that this is a replaceable layer which protects the structural concrete below and that the 20N concrete doesn't react with the effluent as much as the stronger 50N mix, They could have a point because the old 'better' concrete would all have probably been 20N.