Mixing Concrete: What is the Correct Ratio and What Tools Can Help You On the Job?
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Concrete is a versatile building material since ages. It is mixture of cement, fine aggregate, coarse aggregate, and water in controlled proportions of a suitable quality. It is a composite man-made material, and the most widely used building material in the construction industry.
There are plenty of jobs around the house that require relatively small amounts of concrete. These jobs can include patching holes in concrete floors, installing fence posts, or making a stable base for a birdbath, a grill, or other outdoor features. If the concrete is too wet or too dry, it will not set up correctly or have the desired strength. Large concrete jobs require ordering a concrete truck and workers to spread it correctly and quickly so the resulting floor or surface is smooth and level. In this blog, we are going to discuss steps and tools required for concrete mixing.
Purpose of Concrete Mixing
The object of concrete mixing is to make the concrete mass homogeneous and uniform in colour and consistency. All the aggregate particles must have a coat of cement paste and all the ingredients of the concrete must blend into a uniform mass. The concrete mixing is done either by hand or by machine called mixer.
Mixing of Concrete for Large Concrete Projects
Large projects, such as new homes, housing developments, and commercial projects, require professional concrete companies offering Concrete Formwork Systems for walls, slabs, load-bearing systems, stairways, parking lots, and more. Multi-story commercial buildings made with concrete and other commercial buildings require special expertise and equipment. These projects involve architects, project managers, and field service technicians. Engineers draw up assembly and erection plans in conjunction with architects.
Next, there are concrete projects that are planned for existing homes, such as new patios or pathways, new concrete or replacement concrete driveways, or tennis courts. These projects require truckloads of premixed concrete installed by experts. Forms must be constructed and then removed. A professional crew must work quickly to pour and level concrete.
At large building sites, concrete is delivered ready for use, i.e. ‘ready mixed’ to the required specification. The strength and nature of the concrete depends on variety of factors including:
01. its purpose (i.e. the type of work)
02. its durability (i.e. the intended working life)
03. whether the concrete will be reinforced
04. the risk of chemical attack
05. the method of pouring
Concrete Mixing for Small Concrete Projects
There are many small concrete projects the homeowner can tackle. These include projects that will require one to thirty bags of concrete. Projects requiring 30 or more bags of concrete will be more successful with premixed cement delivered in a special truck. But, the small projects accomplished with hand-mixed concrete will be more successful if the concrete is properly mixed. Properly mixing concrete requires the right equipment and a few mixing steps:
Steps of Concrete Mixing
01. Gather the correct tools and purchase the right mix of concrete. Tools to assemble include buckets, a cement mixing tub or wheelbarrow, clean water, a dust mask, goggles, rubber gloves, a hoe or other mixing tools, and a stiff-bristle brush. For larger jobs, rent a concrete mixer at about $35.00 per day. Concrete bags weigh from 60 to 90 pounds. The protective gear is important because concrete is caustic and can cause burns.
02. If mixing cement in a tub or wheelbarrow, set the bag in the mixing container before opening. Slice the concrete bag open with the hoe and then pull out the bag.
03. Leave the concrete at one end of the container and add a measured amount of water to the other end. Do reserve small amounts of both water and concrete mix for later adjustments. Too much or too little water will make concrete that is too soupy or not workable. Read the bag instructions for the recommended water amount.
04. Start pulling small amounts of dry concrete into the water with the hoe and mixing it in completely until all the concrete is mixed with the water. Mix the concrete until it has an even texture, do a slump test for correct consistency, and then add dry mix or water as needed. Mix the concrete until you have a smooth, moldable mixture with no puddles of water.
05. Clean the mixing tools or leave them in a bucket of water. At this point, you have usable concrete to poor in the designated spot. Clean the wheelbarrow or tub immediately because, once concrete hardens, it is difficult to remove. Now, mix the next batch.
To sum up, concrete mixing is done by various methods. For small jobs, hand mixing is used. While for mass concreting, mixing of concrete either done by machine mixture or RMC. Proper mixing of concrete ingredients is utmost importance to get the desired quality concrete. Throughout the mixing phase the surface of all the aggregate particles is coated with cement paste. For the desired workability and performance of concrete in both the fresh and the hardened state, well mixed concrete is required.