Prepare your ground by removing as much of the water as possible. This can be done with a shovel and a wet-vacuum. Dry the ground out even more by throwing an inch of sand onto the ground.
Damp ground will not be a problem unless is can not support the weight of the concrete. Cement/concrete does not "dry" , it cures , a chemical reaction. It absorbs water to cure, as noted , some concrete applications are sprayed with water to aid the cure.
- Dig the ground down to the proper depth. ...
- Smooth out the ground with the flat side of a rake so that you have a level surface. ...
- Tamp the ground with a hand tamper or mechanical tamper. ...
- Pour 2 inches of small, rounded gravel for additional drainage needs.
The American Concrete Institute standards generally prohibit placing concrete on water saturated soil, since additional water will change the "mix design", that is, how much water should be in the mix to achieve a certain amount of strength.
You can place concrete in up to 1 inch of water-concrete is 2½ times heavier than water, and it will displace the water. You might want to thicken the footings in that case, because the bottom of the concrete may absorb some water and be a little weaker than normal.
Long story short, yes you can pour concrete over dirt.
Well, Can You Pour Concrete in the Rain? Surprisingly, yes, you can pour concrete in the rain. Concrete does not dry, it cures. Curing is a chemical reaction and not a physical one, so rainwater won't kill concrete.
THE SOLUTION: LIME!
of either quicklime or hydrated lime, dries up wet soil quickly, so that it can be compacted readily, forming a working table that will resist further wetting as well--you can get back to work! hydrated lime are both highly effective in drying wet clay and silt soils.
Because concrete is a very porous material, it will absorb any moisture that it contacts. This can cause pooling. Without crushed stone, pooling water will settle under it and erode your slab. Adding a layer of crushed stone will add proper drainage, as well as create a barrier between your slab and the ground.
You do need gravel under a concrete slab, footing, or patio. Gravel provides a solid foundation for your concrete as it can be compacted. It also improves drainage, preventing water from pooling beneath the concrete.
Just as every home needs a good foundation, your property's concrete slab needs a good subbase to function properly. Contractors sometimes use sand as a subbase when pouring concrete, but it all depends on the slab's function as well as your region's climate.
Pouring concrete in the rain can compromise its strength, increasing the tendency for dusting and scaling to develop. Once the damage is done, it can be hard to rectify and will often ruin the appearance of the finished surface. Don't let it rain on your parade.
The base in concrete construction is usually a form of crushed stone. Most concrete contractors want a mix of coarse and fine aggregate to create a compactable base that is going to be safe for settlement and drainage.
If you have a concrete floor that's in continuous contact with a source of moisture, you're going to have problems. This is why a vapor barrier under concrete is essential. Vapor barriers are a way to keep moisture from getting into the concrete.
Standard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.
Lime-based drying reagents, such as Calciment LKD, also known as Lime Kiln Dust, and Quicklime, will help quickly dewater wet soils to reach optimum moisture content (OMC). The reagent is applied at a pre-determined dose rate (typically 2%- 5% depending on soil conditions), mixed into the soil and hydrated.
Sometimes it takes as little as two days to dry an area and other times it could take several weeks. Areas that are not that saturated with dryer air tend to be on the shorter end, while humid areas that have been fully saturated will stay wet longer.
While it only takes around 28 days to cure concrete, drying can take months. The general rule of thumb is that concrete takes about 30 days to dry for every one inch of slab thickness.
If the rainfall is heavy, it may wash off cement from portions of the concrete surface. It will weaken the structure and also reduce its durability. Unsealed concrete surfaces absorb water and crack due to freeze and thaw cycles. The most damaging effect of water is the scaling of concrete surfaces.
Although concrete will harden soon after pouring, it's still susceptible to damage from weight during the first four weeks. Wait at least 24 hours before allowing foot traffic, including pets, on a newly poured sidewalk or slab, and don't drive a vehicle on a new driveway for at least 10 days.