Page 62 - Masonry and Concrete

Concrete Construction Techniques
61
CONCRETE CONSTRUCTION TECHNIQUES

FIGURE 3-21
Reinforcing mesh splices.

ingredients accurately for each batch. For best results in mechanical
mixing, load concrete ingredients into the mixer as follows:

1. With the mixer stopped, add all the coarse aggregate and half the
mixing water.
2. Start the mixer, then add the sand, cement, and remaining water
with the mixer running.
3. After all ingredients are in the mixer, continue mixing for at least
three minutes, or until the ingredients are thoroughly mixed and
the concrete has a uniform color. Do not overmix, or the ingredients
will begin to separate.

Always clean the mixer thoroughly as soon as possible after you
have finished using it. Add water and a few shovels of coarse aggregate
to the drum while it is turning. This will scour the inside of the mixer.
Dump the water and gravel, and hose out the drum.

3.6 Pouring Concrete

There are several rules to follow when pouring concrete. The first is
that concrete should be placed in the forms as soon as possible after it

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