Concrete, like cement and mortar, forms a thick paste when mixed and turns into a hard surface when it dries. It seems simple, but you also must ensure that your concrete doesn't dry too quickly, or it forms a dusty surface that cracks easily. Properly curing your concrete gives you a surface that resists stronger forces than concrete that has dried too quickly.
When you cure concrete, it means you provide it with the proper surrounding conditions for it to harden correctly and resist most forces that it meets. Curing begins with a process called hydration which involves a reaction between water and the cement, forming small crystals that bond. The second step of curing slows down the water-cement reaction. A proper cure might take several weeks or years, in some cases.
Concrete doesn't resist abrasion when it dries too quickly. The surface easily turns into dust which exposes the gravel below it, making the concrete look "eaten away." This often happens with concrete cured in the summer without any insulation against evaporation.
How to Cure Concrete
Once you finish a small slab of concrete, don't hesitate to put some curing compound on it right away. Letting the concrete wait more than 10 minutes without curing compound might make the concrete cure weakly. The humidity level in concrete must not drop below 80 percent. Pour a coat of curing compound on the concrete and allow it to settle before pouring a second coat without leaving any gaps. This ensures that humidity doesn't leave the concrete too early.
Seal Your Concrete
Sealant increases the durability and overall lifetime of a concrete surface, especially if you live in an area where water freezes. If water that has absorbed in concrete freezes, it expands the hardened concrete, causing it to crack. Sealant prevents water from penetrating concrete. Don't get just any sealant, though. Read the label to verify whether it works well in your climate.