If you're a newcomer to the field of concrete paving, you probably would appreciate some guidance and insight. Did you know there are many things can affect the way concrete sets, including the weather? Do you know the basics of subgrade, subbase and Visqueen? Newbies should go to sites and be familiar with terms that are frequently used in concrete paving.
If you're a do-it-yourself handyman working on home projects here are some things every newbie should know:
1. The Basic Components of Concrete
This may seem like a silly question, but do you know what concrete is comprised of? If you've never paved concrete, you may be unfamiliar. Basically, concrete is a mixture of cement, sand and gravel.
The sand is the finer aggregate, while gravel is courser. For decorative concrete, stones or marble may also be used. Water and chemicals will also be added to the mixture.
The chemicals give strength and durability to the finished project. It may also quicken the hardening process of the concrete. The chemical admixtures often consist of fly ash, granulated blast furnace slag, metakaolin and silica fume.
2. The Influence of Weather Conditions
Depending upon the climate you live in, you need to consider extreme temperatures that may affect the job of concrete paving. Certain weather conditions may make the task of pouring concrete difficult, even for an experienced contractor. Because hydration is an important process of concrete paving, temperatures below the freezing point is not optimal. In addition, extreme cold makes it difficult for the concrete to solidify.
Ideally, the ground temperature in which concrete is to be paved should be around 50-60 degrees Fahrenheit, or 10-15 degrees Celsius. Conversely, you should not attempt laying concrete during extremely hot conditions, as this may cause rapid evaporation.
3. Subgrade, Subbase, Visqueen and Rebar
Concrete paving involves installation of the above mentioned components. First, you should remove the topsoil so your concrete will adhere properly. After doing so, you need to compact the native soil using a compactor machine. This underlying soil is your foundation. It's also referred to as the subgrade.
A layer of gravel is typically placed on top of the subgrade, and this layer is the subbase. Did you know that a vapor barrier is needed on top of the base? This barrier, a polyethylene plastic sheet known as visqueen, prevents moisture from penetrating the concrete pavement.
To reinforce the concrete, you'll want to install rebar. Basically, this is a reinforced piece of steel. The reinforcing steel is what holds the concrete together. It also prevents cracking due to weather conditions and normal wear and tear. This is particularly important when installing a concrete driveway.
4. Slab Thickness
Do you know how thick your residential concrete slabs should be? Thickness will depend upon the application. Sidewalk concrete slabs are typically four inches thick. Apply the same thickness for a concrete driveway that will be used for vehicles cars only. For parking a boat or RV in the driveway, the slab should be a couple of inches thicker.
5. Concrete Paving Terminology
If you're new to the field of residential concrete paving, here are a few terms to familiarize yourself with:
Aggregate Blend: When you incorporate two or more granular substances, this is an aggregate blend. By mixing the various components, you will achieve a higher grade of concrete. This is especially useful in decorative paving.
Bar Chair: When placing a steel rebar, you may need this device to support it. This keeps the reinforcement steel from shifting during the placement of concrete.
Elephant Trunk: This is an elongated tube that is helpful when placing your concrete slab.
Overlay: This is a basic term for the material that is used when resurfacing a finished concrete pavement. This additional layer of material may improve an existing pavement that has been aged due to certain environmental conditions. The overlay will generally smooth out imperfections or damaged textures.
Concluding Thoughts on Concrete Paving
Keep in mind that it's important to use a quality sealant on your finished project. This will help minimize the need for future maintenance, saving you time and money in the long run. Glossy or wet-look paving sealers not only protect the pavement, they add curb appeal to your application. A water resistant acrylic-resin blend is ideal for most weather conditions and environments.