To pour a concrete slab for a terrace, a driveway, garage or a pool deck, you need to be aware of the precise concrete mix needed. Fortunately, through a simple calculation, you can determine the volume of concrete required for your task! Here is what you need to know to successfully complete your construction project.
Determining the thickness of a concrete slab is an essential prerequisite to order the right quantity of ready-mix concrete for your project. This is no simple matter: the thickness, determined by the engineer, influences the quality and lifespan of your structure. Thus, to avoid any cracks over time and to ensure adequate resistance of your construction, the quality of concrete and reinforcements alone are not enough as prerequisites! Please note: unlike a slab that is considered light, additional thickness of your concrete will not only increase the weight of your structure but also the construction cost. Finding the right balance is thus crucial!
Several factors need to be considered before embarking on a calculation, as the thickness of a concrete slab depends on several parameters. First, we need to consider the nature of the structure itself: depending on the intended use of the project, the slab may need to be thicker or thinner. For instance, the structure will be different if it is being used as a parking lot for multiple vehicles or as a pedestrian walkway.
The nature of the soil where the slab is being poured is another important element to consider: if it is loosely-packed or heterogeneous, it will require further reinforcements with a layer of compact gravel of at least fifteen centimetres.
Lastly, the materials used also matter: not all ready-mix concrete mixtures have the same level of strength and reinforcements tend to affect the rigidity of the structure. Be sure to follow the best recommendations for optimal performance!
To calculate the theoretical volume of concrete needed for your slab, the following formula is generally recommended: volume (m3) = slab area (m2) * slab thickness (m) = length (m) x width (m) x height (m).
Depending on the project planned and on the level of the pressure applied on the slab, its thickness will need to be adjusted. Here are the common standards for various scenarios: