Hello /diy/. The concrete floor in this corridor sinking, it's placed directly under compacted earth. I already opened everything and re-concreted 2 times but it keeps sinking. What should I do? The earth is very compacted and I'm not sure what is causing it to sink.
Sorry didn't noticed that the photos were like this, my father took them. Here's another. It's the part near the wall.
That's what I did the last time. Broke it and used the broken concrete so it won't sink. It's probably water that is causing the earth to move, but I don't think I can do anything about that. I thought about putting steel bars underneath but I'm not sure this would help.
you can't pour concrete on straight dirt and expected it to stay. pic related
Really to prevent that it should have been tied into the foundation with steel. So everything sinks together.
Now you have three choices
1 - dig up the whole thing and do it right
2 - patch work to hide the separation every now and then
3 - leave it as is. Because for fucks sake you have a toilet sitting right there so I am surprised that you even care about aesthetics.
drill 2" angle steel into the foundation to be center of slab
weld 1/2 or 5/8 rebar to span the gap every 24"
place rebar every 12 along length
>It's probably water that is causing the earth to move, but I don't think I can do anything about that.
You probably can. Break up the old concrete, dig some trenches and put in proper drainage to intercept the ground water and divert it off to somewhere harmless. Then properly prepare ground and pour new concrete.
Probably the floor slab didnt rest on the compacted earth in the first place. I dont know whether your building is a two storey house or a highrise, but Im betting it uses a strip foundation for the house.
The outdoor pavement has been sinking, you need to dig the edge of pavement and make a proper strip foundation. And I dont know whether you live nearby lakes or swamp, you may need to turn the whole concrete slab into a raft foundation. Adding more and more layer of concrete wont help, since the normal reaction from the compacted ground isnt really compact.
You may need to get an expert on soil test or DIY for it.
Antoher theory would be the contractor went the cheap way and didnt put a moisture sheet below the slab and it cracks like crazy.
Take out more earth and replace it with more aggregate not just shitty peice of old concrete, a good thick layer of dolomite or something similar, then compact it really good with a petrol whacker plate.
The first time you did it you might not have gone deep enough, so you dug a hole, compacted it, but deeper down its still loose, causeing it to sink again.
Dig it down a minimum of 250mm, more if the ground is still shit. Build back up to within 100mm of finished level with well compacted stone. Compact in layers.
Lay 1000guage polythene, steel mesh on spacers, pour.
Pic related, just on a smaller scale.
ALeo, I'd recommend some sort of expansion joint along the edges touching the wall
>All the replies telling him to do scientific shit or to do it right.
You niggas are dumb. If he had the money or time to do either, it would've been done.
OP, your best bet is >>926098 2 and 3.
Pour a new shitty layer every year or so. Eventually it might stop sinking.
Bongland.they come flat, you loop them then tie with wire. Tbh they're probably the best system I've used. If you're tight on cover you can stamp them down, opposed to the plastic crap that shatters and collapses.
soil, like all materials is a composite material. consider for example, concrete not as pourable stone, but as a matrix for holding water. water is stronk. its just that people dont like to think of it like that. soil expands as it absorbs moisture. then contracts when it dries. many cycles of this expanding and contracting causes a cavity to form under the concrete. now what you have is a bowl that collects water, accelerating the process. you need to consider drainage. drainage wont stop the problem. it will slow it down. but for all intents and purposes, it will slow the process down to the point where it wont happen again for another 50 years. think of it like paint. paint that lasts 50 years is preddy gud paint. but everyone knows that old paint will flake. so your goal, first and foremost, is to reduce the duty cycle of the expansion and contraction. make it so that water cannot pool in the area.
>no drain at all
even just installing a proper drain channel along the edge of that path will dramatically reduce the water that can pool in that area. hell, you can use a piece of PVC pipe as a form, do as you are going to do and re-lay the concrete but this time, half submerge a piece of pvc pipe along the edge in the concrete then remove after a day. now you have somewhere for the water to go.