Concrete Ready Mix Types
Consistency is the main advantage of choosing concrete ready mix over on-site mixes, followed by ease of use. Having the cement and aggregate mixed at the plant ensures that every batch of concrete has the same composition. A poorly mixed batch could see a part of your construction beginning to fail under the impact of rain and temperature changes (also known as the freeze-thaw cycle). Now that we’ve talked about the main types of pre-mixed concrete from the point of view of mixing let’s take a look at some ready mix concrete types from the usage point of view.
The Standard Mix – The most common concrete mix type is the standard concrete ready mix. As the name implies, it is used when the work doesn’t call for anything special. Even so, the mix is prepared at the concrete suppliers’ plant according to the contractor’s instructions. Like all the other types, the standard mix could be fully mixed at the plant or mixed partly at the plant and partly in transit.
The Rapid-setting Mix – This is a mixed used mostly in winter when conditions don’t give builders the time to let the concrete settle normally. However, the rapid-setting concrete ready mix also comes in handy for precast or formed applications and repairs and restoration work.
The Steel Fiber Reinforced Mix – The usual combination of concrete and aggregates is upgraded through the use of short fibres distributed uniformly through the concrete mix. Fibre is added with the purpose of controlling shrinkage during setting and drying to keep the concrete from cracking.
The conventional drying and shrinking process create cracks in concrete and fibres are used to fill in these cracks. Steel fibres are used to improve the structural strength of ready-mix concrete, as well as to increase the resistance to impact and abrasion.
The Propylene or Nylon Fiber Mix – Propylene or nylon are added to the ready mix cement and aggregates to increase mix cohesion and make concrete easier to pump over long distances. These fibres also improve the resistance to impact, abrasion, explosive spalling in a case of fire and ductility.
The Pervious Mix – This is a special mix made with large aggregates that make the concrete more porous, thus allowing water to pass through the concrete slabs and go into the ground. It is mostly used for pavement surfacing and city authorities like it because it allows the trees lining the sidewalks to benefit from stormwater.
However, developers are also interested in it because it pays to let at least some of the stormwater seep into the ground instead of having to install expensive drainage systems. It’s a good mix for backyard paths and other kinds of flatwork if the ready mix concrete price doesn’t bother you.
The Architectural and Decorative Mix – This mix comes in a variety of colours and types of surfaces to allow decorators to do their work. The traditional way of a building called for concrete floors to be covered in tiles, but things have changed recently.
Some people pour coloured concrete mixes in decorative patterns and never bother with the tiles.
The Roller-compacted Mix – This is a blend of concrete that includes fly ash and much less water than other mixes. It’s usually brought to the site in dump trucks instead of transit mixers and spread with the help of bulldozers.
After the concrete mix is spread, it is compacted with vibratory rollers because it’s too dry to be handled otherwise.
Typically, it’s not used in combination with steel reinforcing. While not a common sight in home building projects, the roller-compacted mix is tight, cost-saving and quick to settle.