Black is typically used in home driveways and gas stations because it hides oil stains and grime. Brown hues are common in industrial flooring and some homes. Colored concretes are common in concrete masonry units, concrete pavers, and other forms of decorative concrete.
For an even brighter color, mix your concrete with a white aggregate.
To measure your ingredients properly, consult manufacturer instructions for your cement, oxide pigment, and other concrete materials before adding them to the mixer. Generally, you can mix concrete that is one part cement, two parts sand, and three parts gravel (or some other aggregate). The total weight of the water you add should be about half the weight of the cement.
For instance, if you have 100 pounds of cement, you should add 5 pounds of oxide. Adding oxide at a concentration of slightly more than 5% of the weight of the cement content will result in a darker hue. Adding oxide at a lower concentration will result in a lighter hue. Adding too much oxide will negatively impact the quality and durability of the concrete. If you’re trying to achieve a particular color, you might need to do some experimenting in order to discover the right oxide concentration.
Drum mixers are used to produce large volumes of concrete. These can range from large drum truck mixers (which can produce up to nine cubic yards of concrete) to smaller non-tilting mixers (which produce about one cubic yard of concrete). One sort of drum mixer, the tilting drum mixer, is the best option if you’re using large-sized aggregate or very thick concrete. Pan mixers use blades fixed to an assembly that stir the concrete as the vertical shaft rotates. Like tilting drum mixers, pan mixers are best used with zero-slump or relatively stiff concrete mixes. Pan mixers are best when you need to produce small or medium-sized batches that range from 0. 25 cubic yards to 2. 5 cubic yards of concrete. Continuous mixers are typically reserved for very large projects (dams, foundations, retaining walls, and so on). They usually use a conveyor belt to continuously feed the mixer concrete-creating materials.
The method by which you mix the dry ingredients depends on the total mass of dry ingredients you’re using. For large batches used to create, say, a parking lot, you will need a continuous mixer or a drum truck mixer. If you’re adding dry ingredients to an older, less efficient mixer, your dry ingredients may need to be mixed for up to 90 seconds. The aggregate you decide to use also affects the length of time you need to mix the dry ingredients. Consult the instructions for your aggregate before adding it to the mixer.
If your concrete is too aqueous and sloshes about, you could add a water reducing agent (also known as a super plasticizer) to the mixture. The amount you need to add depends on the volume of concrete you are producing. Consult manufacturer directions for more information. If your concrete is too thick, add water slowly in small amounts until it becomes more workable. Adding more water will lighten the final color of the concrete. Using less water will saturate the color of the concrete.
All forms are made by simply nailing wooden boards together into the shape you wish the concrete to assume. If you’re interested in creating a concrete walkway, for instance, you will probably make several small concrete squares of similar size. Therefore, you will need to turn four equally-sized two-by-fours on their edges so that the narrow part of the board is on the ground. Nail the boards together at their corners. If you’re pouring concrete for the foundation of a home, you will use a single, much larger form.
Two passes across the surface of the concrete with the darby should be enough. After leveling out the concrete, water will pool on the surface. Wait for the water to reabsorb into the concrete before proceeding.
Finally, smooth the concrete over one more time with the floater. Lift the leading edge of the floater and sweep over it in overlapping arcs, just as you did with the darby. After the concrete has dried and hardened somewhat, repeat the smoothing-over process with your steel trowel. Make two or three passes with the trowel to get a smooth finish on your concrete.
It’s impossible to tell how long it will take for the concrete to dry. The time it takes for concrete to dry depends on local environmental conditions. In hot, dry weather, concrete will dry faster. In cool or shaded areas, it will dry more slowly.
After the concrete is completely dry and cured, remove the form.
