What Kind Of Concrete Do I Order - Concrete Mixes
The type of concrete that you order can be the difference
between having a successful project or ending up with something that you
will be tearing out in the future. If you're building a concrete patio,
and it's going to be built In expansive soil, you might think about
using a stronger concrete mix.
The concrete strength will usually be determined by the amount of cement that will be used, water, sand and rock. The size of the rock and the type of cement will also play an important role in the strength of the concrete.
A typical concrete strength that can be used for almost any project, will be around 2500 psi and we need to pay attention to these numbers as they get larger. The mixtures strength usually goes in 500 PSI increments and these increments are usually increased by adding more cement or larger rock, for each cubic yards of concrete.
In other words, a 2500 PSI standard concrete mix usually has 5 - 90 pounds sacks of cement, where a 3500 PSI mix, will have 6 - 90 pounds sacks of cement in it. This will also depend on the rock size that will be used, to create the specific concrete mix.
The size of the rock, will also help in determining, how strong the concrete will actually be. Let me give you an example: the smaller the rock, the more cement that will be required to create the same amount of structural strength, per cubic yard.
With all that said, if you're just pouring a sidewalk or a driveway, you can contact your local concrete supplying company for a recommendation. I have been doing this for years and they haven't let me down yet. Usually the concrete companies have plenty of experience and know exactly what kind of concrete mixture you need for your area and project. If your neighbors have large cracks in their concrete driveway, you might want to hire a professional, to get some advice. Large cracks might mean there are problems with your soil and will require additional construction methods.