Bad concrete pour

[Enoo]

Any idea what went wrong?
Contractor poured the footing in heavy rain but claimed it would be ok.
The top layer is now like hard clay, it flakes off with a shovel. Can I just build on this with mortar bed for dips or should it I get them to 're do the work?
What is the green and pink?
Thanks!

 

[Jadele]

is it not just clay from the surroundings that's washed in on the top and a good jet wash would sort it out?

 

[garyo]

How old is the pour? Sometimes the creamy bits go like that in the first 48 hours.

 

[noseall]

The top of the concrete will be a mixture of scummy settlement and shoite that has washed down from the sides.
It wants a scrape with a shovel. Concrete loves water and can be laid in the rain. Probably benefits from the rain in fact.
Also the surface concrete often dishes like that where the trench sides have pulled on the gear and the middle hasn't.

 

[John D v2.0]

Not supposed to leave uncovered in heavy rain, it'll wash the cement out of the top layer.
Why didn't he cover it after pouring?
In my DIY experience it should be shovel proof after a few days, but 48 hours it might not quite be there. Still shovel resistant though.

 

[noseall]

Not supposed to leave uncovered in heavy rain, it'll wash the cement out of the top layer.

Won't make the blindest bit of difference to a foundation pour. Where will the cement wash to exactly?

 

[Ian H]

What mix do you do for foundations? Ballast to cement.

 

[stuart45]

6 and 1 would be normal, although it's quite rare to use the mixer nowadays as trench fill is common and is easier to use readymix.
Going further back in time it was 1-3-6 for footings.

 

[Enoo]

The pour was almost exactly a month ago now, so would expect it to be pretty well cured.

Thanks for the advice; I will scrap the top with a shovel as does appear to be much harder underneath top layer, 1cm maybe less, and then build off that. Tried to jet wash it but doesn't come off so time for a workout.

 

[John D v2.0]

Won't make the blindest bit of difference to a foundation pour. Where will the cement wash to exactly?

Maybe for Foundation it's fine - I am only going by my bedding block paving and other general tasks etc. I thought it would not be even and would need mixing again after additional water.

 

[tomfe]

If it was a scc you get quite a bit of crud (cement paste) ontop.