Concrete shop floor problem

[Kane]

Hi all,

just wondering if anyone can give me a little advice?

I had a new concrete floor laid recently and had it polished, now when it was laid before the roof went on my workshop it was torrential rain. The company laying said it wasnt a problem - in fact it was the same weather when i personally laid the base of my pond which is rock solid (concrete from a different company though)... so not sure if their mix was bad?
after polishing the floor is powdery and you can twist a screwdriver blade through it. Anyone any advice as I will be lifting almost 3 ton cars on this floor. Is it a rip up and redo or is there anything I can coat the floor with to help? dont want it to crack or move..

this is a 40ft x 50ft floor by the way...

 

[cgallery]

How long ago was it poured, and show us a picture of the screwdriver damage to it.

 

[Kane]

will take some pictures after the weekend, it was actually poured a while ago now, but I havent had time to do anything further with it, but finihsing the workshop this summer is on my list.
As said you can literally "drill" through by just truning a screwdriver into the floor..

 

[LegacyIndustrial]

Pictures would be great.
However, from the sound of it, you may have had too wet a mix and they troweled the pants off it. This leaves a week sandy cap without much strength.

If this is the case you could have them back to "cut" the top and get to where the concrete is stronger. Lots of grinding involved and it will definitely expose aggregate.
It's a nice look, but not everyone digs it.

 

[Kane]

pictures attached, concrete has been down longer than I thought - time flies...

 

[LegacyIndustrial]

The pictures are fuzzy. However, I think you have a weak cap. If you paid to have someone do this I would be having a talk with them about how they are going to fix your floor.

If they want to try and make it work in place, I would do a core sample to see how bad it really is.

 

[Kane]

The pictures are fuzzy. However, I think you have a weak cap. If you paid to have someone do this I would be having a talk with them about how they are going to fix your floor.

hence my problem, the company went bust not long after they did it, they had said they would overlay another 1 inch ontop before they went bust, but i dont think 1inch would take 3ton cars without cracking.