All About How Concrete is Made
Making concrete worktops, and concrete sinks every day means that we have to be experts in our choice material – concrete. We thought it’s probably a good idea to share some of this knowledge with our clients so they can understand a part of the process in making their unit.
What is concrete made from?
In its purest form, concrete is a mixture of paste and aggregates (or rocks). The paste is made from cement and water, and is used to coast the surface of the fine aggregates. In using a well-known chemical reaction known as ‘hydration’, this paste then hardens and toughens into a rock-like form that we call concrete.
Why is concrete used so often?
The reason why this substance is so valuable for us is that it is incredibly malleable while in its pre-hardened state, which allows you to mould it into any shape you want.
The character of the concrete is decided by the quality of this paste mixture, in turn the strength of the paste is decided by the ratio of water to cement. High-quality concrete is produced by lowering the water cement ratio without sacrificing the malleability of the fresh concrete which allows it be properly placed, consolidated and cured, creating the concrete shapes that make our lives better.
What is the perfect make-up of concrete?
The correctly designed blend will have the needed workability for the fresh concrete to produce an optimum shape, and the requisite durability and strength for the strengthened concrete. The mix is approximately 10% to 15% percent cement, 60% to 75% aggregate and only 15% to 20% percent water. Entrapped air in many concrete mixes could also take up to another 5 to 8 percent.
Are there any additional ingredients in concrete?
Almost any regular water that is clean and has no prominent taste or smell may be used as mixing water for concrete. However, any excessive impurities in the water used for mixing may not just affect setting time negatively, it could also affect the integrity of the concrete, and can even cause efflorescence, staining, unsuccessful reinforcement, affect volume, induce instability and also reduce durability. It’s therefore imperative that high quality water is used. We’re very lucky that here in North Wales we have access to extremely high level of water quality, but also in the UK the water is all around very good. This means that we avoid any negative consequences from bad water in concrete.
How is concrete aggregate for concrete chosen?
Aggregate on the other hand, it is more important that we select our ingredients carefully. The reason being is that aggregate makes up over 60% of the total concrete volume. The type and size of aggregates used depends on the thickness and purpose of the final concrete product.
After the aggregate, cement and water are combined, the mixture starts to harden. All the Portland cements are hydraulic cements that set and harden through the hydration process.
once the concrete is thoroughly and professionally mixed, and in a workable state it should be placed in forms before the mixture becomes too hard.
If you’d like to know more about the process, simply give us a call and we’d be happy to go into detail.