Portable mixers are very useful for medium sized concrete projects. They are commonly used when an amount of concrete too big to hand mix but not big enough for a truck load is needed. Most portable mixers are measured in cubic feet which is much easier to estimate for your medium sized projects. they can be rented, or bought out right  but, mostly you will use them rarely for home projects.

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Concrete trucks are most commonly used for commercial use. They have the ability to hold many square yards of concrete. Truck mixers are also able to carry concrete a far distance and be mixed on site. Truck mixing is the most expensive way of mixing concrete. Although, it is one of the fastest ways to have large amounts of concrete delivered.

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Hand mixing usually takes place on smaller home jobs. Hand mixing is the least expensive method of mixing concrete. Hand mixing is also the least efficient way of thoroughly mixing concrete quickly. the easiest way of hand mixing is in a wheelbarrow or with a big pile of dry concrete and adding water. How to hand mix concrete.

Hand Mixing Concrete http://www.concreteexchange.com/how-to-center/concrete-mixes-and-additives/hand-mixing-concrete/