The concrete ratio varies on the strength you want to attain, but as a general rule, a basic concrete mix would be 1 part cement to 2 parts sand to 4 parts aggregates. A foundation mix of one part cement, three parts sand, and six parts aggregates can be employed. As with most things in construction, there are exceptions depending on what kind of material you are using and how strong you want the finished product to be.
The best concrete mixer for your job will depend on how much you plan to mix and how large your equipment is. For example, if you are making only a few batches of concrete, a hand-powered mixer may be enough for your needs. But if you are planning to make a lot of concrete, or if you need a high-quality finish, then you should consider buying a commercial mixer. There are two main types of mixers: wheeled and stationary.
If you are making only a few batches, a hand-powered mixer is the way to go. These mixers use two blades that rotate at different speeds to emulsify the cement and water without using electricity. Hand mixers are available in a wide variety of sizes from small household models to huge versions used by contractors. They usually cost between $100 and $300.
Stationary mixers are also called barrel or cone mixers. These machines use two rotors inside a cylindrical container to mix concrete easily and thoroughly.
Half of the cement, sand, and aggregates (for a concrete mix alone) should be measured. Using half of the mix now will prevent it from drying out before you have a chance to use it all; you can mix the other half later. The mixture should be moist but not wet when added to the forms.
Concrete requires water to hydrate, or cure, into a strong solid. Concrete also requires air to dry properly. Drying too quickly can cause the surface to crack. If this happens, you may need to re-wet areas of the slab with a hose until the cracks stop widening. Any moisture inside the form after adding the concrete mix should be removed because it will accelerate drying and could lead to cracking.
Mortar is a very thin layer of grout used to bind together bricks or stones in a wall. It's made by mixing water with cement powder to create a paste. The ratio depends on what type of mortar you want to make. For example, if you want a fast-drying white mortar, add more water than cement powder. If you want a slower-setting gray mortar, add more cement powder than water. You can make your own mortar or buy pre-mixed bags at home improvement stores.
The key to making good mortar is to keep it moist but not wet.
This concrete mixture ratio of 1 part cement, 1 part sand, and 3 parts aggregate yields a concrete mix with a compressive strength of 2500 to 3000 psi. When water is mixed with the cement, sand, and aggregate, it forms a paste that binds the ingredients together until the mixture hardens. The amount of water required depends on the type of cement used. For example, if sodium hydroxide is added to portland cement, more water is needed than if calcium chloride is used as a water reducer.
Concrete mixes typically include some form of plasticizer to make the mixture workable at lower temperatures. Commonly used plasticizers include dihydroxybenzene sulfonates, aromatic carboxylic acids, and glycols. Dihydroxybenzene sulfonates are the most common plasticizers used in concrete because they cost less than the other types of plasticizers and provide similar performance results.
Plasticizers do not contribute to the final properties of the hardened concrete material. They only help make the concrete easier to work with by reducing its stiffness and viscosity. Once the concrete has set up sufficiently, any remaining moisture should be removed from the surface or it will cause the concrete to crack.
Compressed air can be used as an alternative to water when mixing concrete. This is called air-entrainment mixing and reduces the need for water during the initial setting of the concrete.
1 part cement, 3 parts sand A three-part mix yields a concrete mix with a compressive strength of about 3000 psi. Mix water with the cement, sand, and stone to create a paste that will bind the materials together until the mixture solidifies.
The type of rock you use affects the mix you need. For example, if you are using granite, use a mix that is slightly wetter than normal. This allows the granite to absorb more water, which helps the material bind together better.
There are two types of mixes used for concrete driveways: full and partial. With a full mix, there is enough liquid added to the dry ingredients to produce a pourable substance that can be poured into a slab or onto an existing surface. As it sets, the concrete gains weight and becomes harder.
Partial mixes have less liquid than full mixes, so they won't set as hard. You would use this type of mix when you don't have access to a pump to add more water to the concrete, such as if you are pouring the slab over an area that isn't flat or if your tap water has high minerals in it. Partial mixes are also useful if you want to add other materials to the concrete while it's still soft. For example, you could add gravel to a partial mix to create a rolling road surface before it sets.