Mixing Concrete By Hand
The wonders of modern construction never cease to amaze us. As a society, we have grown accustomed to seeing our homes built of materials that hardly resemble their origin. For instance, one would never know that a tree had anything to do with a home built of wood, in spite of the fact that its floor, walls and roof are framed with it. Neatly painted siding and meticulously papered walls conceal any evidence of assemblage.
This was not always the case. Abraham Lincoln grew up in a home built of logs. The logs were both structural and aesthetic and acted as the interior and exterior finish. With this type of construction, what you saw was what you got! So popular was this style of early American construction, it was eventually sensationalized by the toy industry with the creation of “Lincoln Logs.”
By the same token, stucco, brick and other man-made cementicious siding materials have long since replaced a home that was built of stone.
While homes are still being built using wood and stone, their prevalence and the extent to which they are used is pale when compared to days gone by. Today, building product manufacturers produce an array of man-made products designed to preserve our natural resources and improve the lasting quality of our housing. Although this is not true in the case of many “modern” materials, the majority of innovative building materials meet or exceed this challenge.
One construction material with a “natural” origin which use has increased is concrete. Actually, “concrete” refers to the hardened mixture of Portland cement, sand and gravel or crushed stone. Heating and pulverizing a mixture of limestone and clay makes Portland cement. It is called Portland cement due to its Portland, England origin.
In contrast to many other building materials, concrete is used widely in both residential and commercial construction and is essential to the construction of many roads, tunnels and overpasses. Conversely, concrete can be used for something as simple as anchoring a fence post or constructing a path or patio. In any case, one is hard pressed to find a material with the multitude of uses and versatility of concrete.
In today’s homes, concrete is used to construct foundations, building slabs, driveways, carports, paths, patios and even wall construction. The strength and quality of concrete is determined by the ratio of Portland cement to fine aggregate (sand) and coarse aggregate (gravel or crushed stone) and the amount and quality of water used in the mix. Thickness of the concrete, steel reinforcement and curing time are other elements that contribute to the strength of the finished product.
Concrete for big jobs such as a foundation or slab is most often delivered to the job as a “ready-mix.” This means that the various ingredients have been mixed at the batch plant and are trucked to the site in a special mixing truck.
Another means of obtaining ready-mix concrete is to purchase it from a plant that will supply it in a trailer that can be towed behind a vehicle. This method is especially popular for small to medium sized projects that are too small for a concrete truck, yet too large for dry mix cement purchased by the sack. Long fences with many postholes or a small equipment pad are examples of projects that can be effectively performed using this tow-behind method.
The means that most do-it-yourselfers have experience with is dry mix cement. It is ready-bagged with correctly proportioned amounts of cement, sand and gravel. All the user must do is add water. Bagged concrete is especially useful for small projects such as repairing a fence post, anchoring a basketball goal or patching a curb.
If your project is larger than can easily be accommodated by bagged concrete, and you don’t want to order ready mix, you can mix your own general-purpose cement. It is good for just about everything with the exception of foundations and exposed paving. General-purpose cement can be made as easy as 1-2-3 — one part cement, 2 parts fine aggregate, and 3 parts coarse aggregate. Add water to create an oatmeal-like consistency — too much water can weaken the mix.
The water used for mixing the cement should be clean and free of oil, acid and vegetable matter. Water that is fit to drink is the best water to use when mixing cement. The right proportion of water will provide proper “hydration” (chemical bonding of the ingredients). Too much or too little water can make a disaster of the cement mix.
Finally, don’t forget one very important ingredient with any concrete job around the house — little hand and feet prints and a date scribed in the surface that will bring special memories for years to come.
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