They are not the same thing although many use the terms interchangeably. Cement is used to make concrete. Cement is mixed with other things including water and it then turns into a mass that becomes hardened and is called concrete.
Slump is the amount of water in concrete mix which shows its consistency. The lower the slump the dryer the mix will be. If water is added to the mix past what is specified, it can result in reduced strength and the possibility that the surface will deteriorate.
Topsoil does need to be removed before the concrete is placed. Topsoil and other organic material are too unstable to support slabs of concrete. The subgrade of cement should contain no organic material and this is very important for having a quality concrete slab.
Concrete is available in almost any shape, pattern and color. There are many specialty materials available such as concrete forms, stamps, dyes, texture patterns, and stains, etc. These applications can be used both inside and outside of your home. If you can imagine the decorative finish, it can be done by a skilled concrete contractor.
Concrete work requires knowledge and skill. There are fundamental skills that the average homeowner does not have. Some basic skills that are required are using a hammer, chalk lines, and saws; however, more specialized skills include the use of straightedge, a concrete edger, a hand float and others.
Besides the use of tools, other areas of expertise include site excavation, preparing the subgrade, putting in concrete form. These areas and the work of placing and finishing concrete is very difficult work. Also, concrete is quite heavy and the timing of the finishing of the project is critical. For all of these reasons and more, most homeowners feel that it is necessary to hire a concrete contractor to do their concrete project.
Curing is one of the most important steps in concrete construction, because proper curing greatlyincreases concrete strength and durability. Concrete hardens as a result of hydration: the chemical reaction between cement and water. However, hydration occurs only if water is available and if the concrete’s temperature stays within a suitable range. During the curing period-from five to seven days after placement for conventional concrete-the concrete surface needs to be kept moist to permit the hydration process. new concrete can be wet with soaking hoses, sprinklers or covered with wet burlap, or can be coated with commercially available curing compounds, which seal in moisture.
The recommended time can be any time from three to seven days depending on the load that will be on it. Ask your concrete contractor for specific directions on when your driveway can be put back in service.
Your concrete needs to air dry for 30 days before you apply a sealer. A sealer prevents moisture from entering the concrete which helps keep the concrete from deteriorating during weather cycles of freezing and thawing. Sealers are usually effective for a couple of years but ask your concrete contractor for specific application rates.
Concrete needs to be frequently cleaned with sweeping and hosing it every so often. Keep wet leaves off of concrete as they may stain the concrete.
Temperature extremes make it difficult to properly cure concrete. On hot days, too much water is lost by evaporation from newly placed concrete. If the temperature drops too close to freezing, hydration slows to nearly a standstill. Under these conditions, concrete ceases to gain strength and other desirable properties. In general, the temperature of new concrete should not be allowed to fall below 50 Fahrenheit (10 Celsius) during the curing period.
Although it may be tempting to roll up your sleeves, mix up some concrete, and tackle a concrete project yourself to save money, you will likely spend most of your time preparing for the project. From planning a complete and realistic budget to considering help from professional concrete contractors for certain steps of the project to making sure your project is allowed by the local permitting office, there’s a lot to do before you start mixing up that gray matter! Pouring and finishing concrete is hard work, and often the convenience of hiring a contractor outweighs the enticement of a challenge for most homeowners.
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.