In its simplest form, concrete is a mixture of paste (cement & water) and aggregates (sand & stone). The paste coats the surface of the fine (sand) and coarse (stone) aggregates and binds them together into a rock like mass known as concrete. In addition to paste and aggregates, concrete may also contain highly specialized chemical admixtures that enhance the specific properties of concrete. Chemical admixtures are used to improve both the workability and/or the durability of concrete.
The key to achieving a strong, durable concrete for your projects are as follows:
The first step in any concrete project is utilizing high quality raw materials. All members of the Ready Mixed Concrete Association of Ontario (RMCAO) utilize only raw materials that meet CSA standards for concrete production (visit www.rmcao.org
for a list of local concrete producers).
Being aware of the minimum concrete specifications required for your concrete application. In Ontario, these requirements are dictated by the Ontario Building Code and CSA A23.1 – Concrete Materials and Methods of Concrete Construction.
You should be aware of these minimum requirements and you should ask your contractor what they propose to use for your project. If they suggest anything less than these standards, or if they don’t know what the minimum requirements
are, you should find another contractor.
in the process is hiring a quality contractor to complete the work. You should use a contractor that has been trained to an industry certification standard such as the ACI Flatwork Finishers Certification Course and ask for a list of previous
projects and references. Make sure to visit projects that have gone through at least two winters and look for any signs of deterioration.
To ensure that your contractor follows proper curing practices and cures the concrete effectively. 7 days of curing is recommend for all exterior concrete flatwork and 3 days of curing is required for all other concrete. Failure to complete
this step properly will negate all of the good work done during the previous steps. Care must also be taken to maintain and protect your concrete investment. Avoid the use of eicing chemical during the first 12 months and consider
the application of concrete sealers to further protect the concrete.