Our useful concreting guide provides you with easy step-by-step tips on how to attain a flat and professional concrete finish.
Choosing a Concrete Mixer
In order to be effective and do its job, concrete needs to be mixed both quickly and efficiently; something which isn’t practical to do by hand. For this reason, it is important to invest in a concrete mixer. Concrete mixers are available in different sizes to suit different needs; from larger commercial needs to home DIY projects there will be a concrete mixer suitable for your requirements. The majority of concrete mixers work the same however size is the largest varying component that you will need to base your decision on.
The Concreting Process
As previously mentioned, the most important thing to note when choosing the right concrete mixer for your needs is size. If you are going to be needing concrete for a large area, you are better off selecting a large mixer as it prepares more concrete at one time which in turn makes your job easier. For larger jobs, bulk concrete mixers are generally the better choice but for smaller projects a tip-up concrete mixer will do the job as it can still mix a good amount of concrete.
For on-site mixing, the correct mix ratio (cement:sand:stone) depends on the application; high strength requires more cement and rougher applications require more aggregate. The ratios given below are given as a guide to common applications. Use a concrete mixer to form your cement.
The Concrete Mixing Ratio
When working with concrete it is important that you know what strength of concrete your job requires. Not every job requires the same strength of concrete and this should be considered before you start mixing it. There are a variety of different uses for concrete including fence posts and garden paths and higher strength tasks such as motorway bases and house foundations. As each task requires a different strength of concrete, this means that when mixing concrete, the ratio will differ from job to job. Concrete is made of four materials; cement, sand, aggregate (stone), and water. The ratio of aggregate to sand to cement is a key factor in determining the strength of the concrete. In addition to this; water also plays a determining roll in how strong the concrete is. The less water, the stronger the concrete tends to be however it can sometimes be harder to work with. By ensuring you measure the ratio each time you can be certain you will have a consistent concrete mix throughout your project.
Bulk Concrete Mixer Applications
|Rough mast concrete||1||4||8|
|Watertight floors,tanks,pits etc.||1||1.5||3|
2. Poke It
Thorough compaction and removal of air is essential for concrete to achieve full strength and durability. The most effective way of achieving this is the efficient use of a vibrating poker. The area around the poker will be fully compacted. The size of this area depends on a number of factors like the size of the poker and frequency and amplitude, and slump of the concrete.
3. Lay It
Concrete floor slabs need to be compacted, flat and at the right level. This process is known as screeding.
Two distinct techniques are commonly used for screeding; traditional screeding using framework/screed rails set at the right height and free screeding using laser levels to achieve the correct level. Use a Beam Screed to accurately compact and level your concrete slabs.
4. Finish It
The screeding process will leave slight ripples on the concrete surface. For some applications this is acceptable as the texture can increase the effective slip resistance on slopes and ramps. When the concrete is still in a plastic state the surface can be re-mixed and surface irregularities smoothed out using a float. This process is quick and easy and if the right tools are used. A wide float blade is pushed and pulled across the slab using a long handle so the operator can work the slab from the sides. Floats can also incorporate a brush to reintroduce a texture to the concrete surface.
It is important that when working with concrete you take the necessary safety precautions and read the instructions to ensure you are using it correctly. When operating a concrete mixer make sure you wear long sleeves and pants, gloves, safety goggles and closed-toe shows when operating the mixer to avoid injury or accidents. Always make sure you set up barriers and signs which warn people of the wet concrete; it would be dangerous and a pain if someone were to walk over your wet concrete.
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