How long should I let new cement cure before I can build on it?
Yes, watering will help the curing of the concrete, not making it faster but reducing shrinkage cracking due to the loss of moisture at the surface. You can either set up a light sprinkler to keep it wet, or use wet blankets. Generally, concrete should be allowed to cure for at least 3 days before you build on it. This is dependant on the strength of the concrete you placed and the load you will place on the concrete. The concrete will reach it's design strength within 28 days, with very minimal gains after that time. Make sure you allow the surface to dry if you are water curing the concrete before you begin to build.
Yes, water is essential to a proper concrete cure.but as a note to the gunslinger (number 1 answer), yes cement does cure. Concrete does not cure. Concrete is a mixture containing cement, (usually portland cement) and the cement within the concrete mixture does indeed cure. The rest of concrete is predominantly aggregate. This is added for compression strength in the finished product, but essentially, aggregate materials are just sand or gravel. These materials do not cure. Back to the curing process. The cement needs water to develop calcium silicate hydrate. This is the principal bonding agent in portland cement, and by extension, most concretes. Without additives, the cure time can go on as long as a month, but a great majority of the strength with be achieved during the first week, and even more critically during the first 72 hours. Wait for the concrete to set, then gently water it for the first 72 hours at least. Using materials to retain water like blankets or towels, or vapor barriers like plastic sheeting will help to conserve water. In smaller applications, a constant source of hydration may be more appropriate. Most commercial concretes, as well as those available through retail and commercial outlets contain additives to help with hydration, and require less help. Read the package and there is sure to be a set of curing instructions. Refer to them if they are available. If not, 72 hours to 7 days of constant moisture is advisable.
First of all, cement does not cure... ncrete cures. Cement is just one component of concrete. The curing is the hydrating of the lime that sets up and develops its strength. Concrete will reach about 80% of its strength in 7 days. Almost 100% after 28 days. There are many kinds of concrete depending on the admixtures. These can slow down curing, speed up curing, hardeners and strength modifiers, cold weather and water-proof. Generally speaking, 8 hours after placing the concrete, cut your control joints (concrete shrinks as it cures, about 1/8 per 10 feet of length) and to lay wet burlap on the surface. This will slow curing but help with consistant curing. Corners will cure faster and accentuate cracks if control joints are not adequate.
This Site Might Help You. RE: Will watering new cement help it to cure? How long should I let new cement cure before I can build on it?
Avoid building on it for at least 4 to 10 days, depending on thickness. Concrete in industrial applications is deemed to have reached a high percentage of its final strength after 28 days, which is when it is tested. In reality, concrete continues to cure and harden for years!
