| Concrete is the most commonly used man made | | | | Pouring concrete, such as a sidewalk, |
| building supply on Earth. Six billion cubic | | | | requires several steps. First, figure out |
| meters are manufactured a year, in a $35 | | | | how much you need. This is determined by |
| billion industry. This means there are | | | | measuring the surface area and thickness to |
| pretty good odds that you'll eventually do | | | | determine how many cubic yards you need, and |
| something with, or be around something with | | | | this will tell you whether you can mix it |
| concrete. | | | | yourself, or need to have it delivered. |
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| Weather and climate will affect your | | | | Then you build your forms. This probably |
| concrete. It is not wise to pour your cement | | | | involves digging, and laying 2"x4" boards to |
| in conditions that involve a drop below | | | | hold the edges of the concrete. 2"x2" boards |
| freezing before the cement cures, as this | | | | should be used to hold those in place, |
| will prevent the cement from reaching its | | | | pounding them deep enough that the weight of |
| maximum strength. Likewise, if the humidity | | | | the concrete won't push the boards out of |
| is too low, the surface of the cement can | | | | place. |
| crack and produce weaknesses for weather to | | | | |
| attack. | | | | You will almost always want to lay |
| | | | reinforcing material in the bottom, such as |
| All concrete will eventually crack to some | | | | metal fencing materials. Ensure that you |
| extent, though this can be minimized by good | | | | have everything square and at the proper |
| design and selection of good reinforcement | | | | level, as after you pour, it will be too |
| where needed. This does not mean concrete is | | | | late. Then ensure that all of the pieces are |
| a bad choice, as concrete structures have | | | | well secured with nails and clamps. Spray |
| lasted thousands of years. | | | | the site with later lightly, and pour. Tamp |
| | | | the concrete down, especially on the edges, |
| Concrete is used as a fire barrier, but while | | | | and level the concrete. |
| it doesn't burn, it can be damaged by heat. | | | | |
| Once the temperature reaches or exceeds 300 | | | | Once it has set enough to support a 2"x8" |
| degrees, the concrete is considered unsafe, | | | | board, use one as a straight edge to cut |
| and this can usually be detected by a pink, | | | | contraction joints. These should be every |
| light gray or yellow-brown color. Discolored | | | | four to six feet. For sidewalks or narrow |
| concrete should be replaced. | | | | areas, this is sufficient, but for patios |
| | | | these should go in both directions. A pair |
| For handyman style use, bagged cement is | | | | of beveled clapboards can be used. Coat them |
| perfectly reasonable, and for convenience, | | | | with motor oil and place a nail into one. |
| there are pre-mixed bags with aggregate | | | | Insert them into joints on large concrete |
| already mixed, just requiring water. These | | | | structures. As the concrete begins to set, |
| are very handy for small jobs such as setting | | | | the nail is used to remove one of the boards, |
| a pole into the ground for a doggy chain or | | | | and the other is hidden inside, leaving room |
| clothesline. This is usually too expensive | | | | for the concrete to expand or contract with |
| for large jobs. | | | | the weather. |
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