The enclosed area is continuously flooded with water, and Portland cement is a hydraulic cement that sets and hardens in the presence of water. Concrete made with Portland cement will harden even if it is completely submerged. To cure a concrete slab, one technique is to build an earthen dam around the perimeter of the slab, flood it with water, and keep it covered for a week. This method is often used by large-scale builders, as it helps to speed up the construction process.
Curing in ponds is an activity that lasts three days, and no daily care is needed, just be sure to maintain the water level above the concrete slab. Keep in mind that it takes a lot of soil to form berms around a large concrete slab, such as a foundation slab. After pouring the concrete, there is a drying process in which the excess water must evaporate, but not dry out completely. Like curing, this drying can take several weeks - a good rule of thumb is that it takes approximately 30 days for concrete to dry for every inch of concrete poured.
When concrete is poured under water, one of its compounds reacts with water to form an outer coating. This coating prevents a large amount of water from leaking out or diluting the cement. Then another compound in the concrete reacts at a slower rate and reaches its final hardness 28 days later. Water-cured Portland cement is a hydraulic cement that sets and hardens in the presence of water.
Any drying weakens the reaction, so that concrete that sets can be stronger than concrete that sets in the air. If you're wondering how long it takes for concrete to set, one solution to your concrete setting needs is a concrete warming or cooling blanket. Concrete moisture testing has been carried out since the 1960s and today there is a scientifically proven way to easily test the moisture content of a concrete slab. It is usually recommended to wait at least 28 days for concrete curing, but there are systems that will allow you to start much earlier. A good way to ensure that your concrete sets correctly is to pour it when temperatures are expected to stay above 50 degrees for five to seven days.
A concrete professional will add the right amount of water for drying that is not too slow or too fast. The difficult part is closing the parking lot so that the concrete product can be set up correctly, all without leading tenants to despair. You can't tell if concrete is dry just by looking at its surface because the surface is almost always drier than the center of the slab. Although concrete is cured, the outside temperature can play an important role in the quality of the poured and finished product. Covering plastic-cured concrete keeps it cleaner, but there is a more important purpose behind this practice - pouring concrete in the rain can compromise its strength, increasing the tendency to develop dust and scale.
