Which concrete mix for foundation

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Search Submit Clear. Search Submit Clear Home. About us. Customer Experience. Supply Chain. Building Products. Marine Aggregates. Packed Highways. Specialist Products. View all. Cement is the active binding agent that reacts with water and hardens the concrete. Aggregate levels and size add to the overall compressive strength of the concrete.

The more stone you use the stronger the concrete mix will be. The same is true as the aggregate gets larger. Aggregates are materials such as sand, gravel, or crushed stone that, along with water and Portland Cement, make concrete. Footings typically have rebar to strengthen and reinforce the concrete. Honeycombing happens when aggregate is too large or course and sits against rebar creating voids that resemble a honeycomb. These voids weaken the concrete and can lead to cracks. They also reduce the compressive strength of the concrete.

You can correct honeycombing by adding more cement and fine aggregates like sand or small smooth stones into the mix and by mixing the concrete properly. Too much water and the concrete will be weak. Too little, and it will be brittle and weak. In general, 3 quarts of water are used per 80 pounds of dry concrete. This is pretty universal no matter the strength of the concrete. However you should vary the water level as needed if your using additives or stronger cement.

Once you add the water and mix the concrete thoroughly, you can perform a very simple test. Take the concrete in your hand and form it into a ball. It should have the consistency of thick oatmeal and should hold form like a snowball. The cement should be sticky like a paste. Using less water generally makes the concrete stronger.

But you need enough to thoroughly mix it and to use up all the dry concrete. The best concrete mix for footings is actually pretty easy to make. The formula above will yield around a psi concrete at 28 days curing time. If you need a stronger concrete, use more or larger aggregate stones or consider an additive. Quikrete makes some of the best pre-mixed concrete for footings.

They come in 60 or 80 pound bags and are ready to go. Just add water. The strength varies from to psi which makes them strong enough for almost any footing. Make sure to use just enough but not too much. If your buying concrete from a truck then let them know exactly the strength you need.

Many novice masons or lazy concrete truck drivers will spray the shoots with water to make the concrete flow better. This makes work easier but weakens the concrete and your footings.

Because concrete gains 99 percent strength in 28 days, it is close to its final strength, so we use this strength at the base for our design and evaluation. Coming back to grades of concrete, the table shows the proportion of cement, aggregate, sand, and water in different grades of concrete.

For M5 grade, the mix proportion is 1 : 5 : The quantity of water required is 60 liters. In the same way, you can see the mix proportions of other grades of concrete up to M Up to M25, a nominal mix can be made for small-scale construction where concrete consumption is not high.

For M 30 and above grades, Design Mix should be used. You can see that as the strength of concrete increases, the cement content is constant in proportion but sand, aggregate, and water content are reduced. If you add more water to the concrete, its strength decreases and vice-versa. Different proportions of the same four ingredients yield different strength mixes of concrete for structural and non-structural parts of a building Lightly edited transcript: Concrete is a mixture of cement, sand, aggregate, and water, which hardens with time.

Just take the case of building construction.