Concrete typically takes 24 to 48 hours to dry enough for you to walk or drive on it. However, concrete drying is a continuous and fluid event, and usually reaches its full effective strength after about 28 days.

Pouring Concrete in Rain. 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.

If the rain occurs when the concrete is fresh (about 2-4 hours after mixing), the surface should be protected from the rain. If the finishing process was recently completed, rainwater may not cause damage as long as it is not worked into the surface and the slab is left untouched.

If there’s a severe downpour and too much groundwater gets into the concrete, the concrete will weaken. To avoid this problem, you’ll need to cover off the area and try to keep the rain as far from it as you can.

Temperature Ranges for Pouring Concrete When temperatures dip below 40°F, the chemical reactions that strengthen concrete slow down and can lead to weaker concrete. If concrete curing temperatures are below freezing, the water inside the concrete can freeze and expand, resulting in cracks.

Your new concrete is designed to reach 90% of its full strength potential after 7 days, so feel free to drive your personal vehicle on it then. It will take additional time before you can drive or park heavy equipment or machinery on your newly poured concrete, so make sure to wait at least 30 days.

ANSWER: Keeping concrete moist helps the curing process. If too much water is lost from the concrete through evaporation, the hardening process slows down or ceases. Concrete continues to gain strength after pouring for as long as it retains moisture, but the longer it moist-cures, the slower the rate of strength gain.

One of the most common methods for curing concrete is to hose it down frequently with water—five to 10 times per day, or as often as you can—for the first seven days. Known as “moist curing,” this allows the moisture in the concrete to evaporate slowly.

The forms or “molding” that holds the concrete in place until it dries should be left alone for at least two days to ensure that the concrete is completely dry. If the forms are removed too soon, the concrete can begin to sag, crack and collapse, especially if conditions like temperature affected its strength.

What might happen if heavy rain falls 10 hours after concrete is poured? Probably nothing. After 10 hours the concrete should have “set ” enough so that the rain will not damage it.

The key thing to remember when curing concrete is moisture. Water causes the mixture to bond and is vital to the chemical reaction that takes place to give concrete its strength. If water evaporates too quickly the concrete’s strength can be compromised and you may end up with cracks.

Long story short, yes you can pour concrete over dirt.

If there isn’t enough water, the crystals can’t grow and the concrete doesn’t develop the strength it should. If there is enough water, the crystals grow out like tiny rock-hard fingers wrapping around the sand and gravel in the mix and intertwining with one another.

Curing time of concrete is typically 24-48 hours, at which point it’s safe for normal foot traffic. After one week, concrete is typically cured enough to handle continued construction including heavy machinery. Concrete is recognized to have reached full strength 28 days after placement.

Assuming that the concrete was mixed in the proper ratio and poured in an acceptable temperature environment, soil backfilling will not harm the curing concrete (assuming no mechanical stresses or insults were done to the curing concrete; that is, no fractures, scours, washouts or chemical exposure).

How long to keep it wet depends on temperature and the mix—you want it to have reached sufficient strength on the surface. Typically, about 7 days is sufficient with Type I cement—less in warm weather.

Spraying water on your new concrete is one of the best and oldest ways to cure your concrete. After new concrete is poured and finished the concrete begins its curing process. Spraying water on the surface prevents the surface of the concrete slab from drying faster than the bottom.

When faced with damp in concrete floors, there are two options available:

1. Dig up the old concrete floor, install a new damp proof membrane and lap up edges before replacing the concrete slab.
2. Fully isolate the dampness in the floor using a surface Damp Proof Membrane (DPM)

Cover it with plastic or damp cardboard for a minimum of three days. A week is even better. For large slabs there is even some benefit at 28 days. In dry weather, mist the concrete surface several times a day and keep it covered to retain the moisture.

50 degrees Fahrenheit

Experts agree that the best temperature to pour concrete is between 50-60 °F. The necessary chemical reactions that set and strengthen concrete slow significantly below 50 °F and are almost non-existent below 40 °F.

Discoloration on the surface of new concrete can be from several factors including inconsistent mixtures, too much or not enough water, low quality materials, poor workmanship, the use of calcium chloride, environmental issues, or issues created during the pore or during the curing process.

Cleansing — For mild discoloration, repeatedly flushing the hardened concrete surface with hot water, then scrubbing with a stiff brush, can reduce or remove discolored blotches. Acid treatment — If the discoloration is more severe, a mild acid solution of 1-3% muriatic acid to water can help remove the discoloration.

Calcium chloride in concrete is a primary cause of concrete discoloration. The resulting low water-cement ratio affects the hydration of the cement ferrites, which contributes to a darker color. Concrete surfaces that are troweled too early will increase the water-cement ratio at the surface and lighten the color.

Another option for coloring concrete is to apply a color hardener to the top layer of concrete after it has been poured. While a color hardener can produce more vibrant colors than adding colorant to the mix, any dings or edges in the finished slab will show, since the color is only on the surface of the concrete.

What causes pink discoloration on white concrete? This is usually caused by a reaction between the alkalies in the concrete and phenol-formaldehydes in the plywood form. The reaction produces a number of pink colored dyes.

Does concrete colored with Davis Colors fade? The color can’t fade, but the concrete can. The active ingredient in every Davis product is pure inorganic pigment which is made in a process of oxidizing metal, in essence, “fading” metal into a pigment powder.