A brief guide to ready mix concrete: What every contractor should know

No one ever enters the construction business with every piece of knowledge already in their arsenal. Even civil engineers and architects require experience to consolidate the knowledge they gain in college, so everyone goes through that learning phase in this industry. Today we are going to concentrate on understanding ready mix concrete while focussing on a few key factors that could make all the difference.

Ready Mix Concrete (RMC): The Definition

Ready mix concrete or RMC has plenty of advantages over regular, site mix concrete, but it all stems from the way these two are made. Ready mix concrete is made according to proprietary or customised specifications and instructions, which the concrete manufacturer follows to the letter.

Keep in mind that the basic ingredients of RMC are still the same as regular concrete, namely, lime, silica, alkaline, sulphur trioxide, calcium sulphate, alumina, ferric oxide, magnesia, aggregate, and water for the most part, but the formula mentions how much of what needs to be mixed under what conditions and for how long to get a product that is superior to site mix concrete in every possible way.

What Exactly are the Advantages of RMC?

Quality – The quality of RMC is by default significantly better than site mix concrete because site mixes cannot possibly be expected to have the same level of quality control standards in place, as compared to what is possible inside a specialised, sophisticated, and closely monitored ready mix concrete factory.

Faster Output – Although the numbers will vary depending on variable parameters, getting the necessary output is always going to be multiple times faster than what could ever be possible with site mix concrete. For example, a concrete calculator was used to get the following mean results.

  • A single 8/12 mixer can produce 5 m³ of site mix cement in 60 minutes
  • About 50 m³ of ready mix concrete can be produced within the same time period or less

Reduction of Cement Consumption – Due to the ready mix cement production process being mostly automated, it has almost no chance of making or missing errors. Also, ready mix concrete production usually requires roughly 10 per cent less cement than is necessary for site mix concrete production, on average.

Importance of Having the Right Calculations

Just ensure that you use your concrete mix calculator properly to get an accurate estimation, or it’s going to be a costly mistake. On the other hand, due to the speed at which RMC is produced, being able to work with the right calculations will boost profit margins for the contractor quite significantly. Therefore, you should use MixIt’s handy calculator to know exactly how much ready mixed concrete you will be needing for the job.

Next, use their screed calculator to find the right thickness necessary (25mm – 75mm) for levelling the foundation and laying a base for the finishing. After you have the necessary numbers, consult with the RMC experts at Mixit and they will both supply and guide you with the concrete you may need for your project/projects.

Are there Different Types of Ready Mixed Concrete?

Primarily, there are three types of RMC, but multiple variations of these three are also there of course.

Transit Mixed Concrete, aka Dry Batched Concrete – The cement mixer is spun fast enough to create the necessary charging speed, but only as long as the mixer is being loaded. Post the loading phase, rotation speed is brought down to normal.

Central Mixed Concrete – The RMC is premixed at the factory itself, and after loading the concrete into the mixer, it’s only spun at an agitating speed to keep the mix from solidifying during delivery.

Shrink Mixed Concrete – This one is a hybrid of the two already mentioned – shrink mixed concrete is to an extent already prepared at the factory, but the rest of the process must be completed in transit and at the site.

Do Contractors Always Use Ready Mix Concrete?

Contractors may advise a client towards opting for a particularly potent and apt variety of ready mix concrete for the project, but they will not use it unless the client approves it. Nevertheless, due to the higher quality, most contractors will recommend ready mixed concrete. It’s always worth the initial expense though because RMC just has so many advantages going for it.

Do be aware that if there’s a long distance in between the factory and the construction site, there is a chance that the concrete might settle in transit. Of course, this can be temporarily countered with admixtures that extend the settling time, but long distances and bad traffic can make even that useless. So, it’s best to get your ready mix concrete delivered at night, during hours that experience the lowest traffic congestion on the route.