Ready-mix concrete is concrete that is produced in a batch plant, according to a put down engineered mix design. Batch plants mix a precise amount of gravel, sand, water, and cement together by weight, permitting specialty concrete mixtures to be constructed and executed on construction sites.
Types of Ready Mixed Concrete
There are mainly three types of ready mix concrete (RMC):
- Transit mixed concrete
- Shrink mixed concrete
- Central mixed concrete
1. Transit mixed concrete
The transit mixed concrete is also known as dry-batched concrete because all the fundamental ingredients containing water are charged directly into the truck mixer. The mixer drum is rotated fast at charging speed during the fill-up of the material and after that, it again starts rotating at a normal disconcerting speed.
While being transported in the direction where it should be taken to its final destination, the drum is rotated at a slow or disconcert speed of 2 rpm, but after reaching to the destination or constructional site just before releasing the material, it is rotated at the maximum speed of 12 to 15 rpm for nearly 70 to 100 rotation to make sure homogeneous mixing.
Concrete mixed in transit
The drum speed is taken to the medium during the transit time, which is approximately 8 rpm for about 70 rotation. After 70 rotations, it is decelerated down to a disconcerting speed of 2 rpm till releasing the concrete.
Concrete mixed in the construction sites:
The drum is kept at a high-speed of 12 to 15 rpm for about 50 rotations in the construction field. The concrete is then disconcert decelerated during transit time.
2. Shrink mixed concrete
Shrink mixed concrete is half mixed in the plant mixer and then balance mixing is conducted in the truck-mounted drum mixer at the transit time. The amount of mixing in transit mixer based upon the expanse of mixing prepared in the central mixing plant. Tests should be done to develop the requirement of mixing the drum mixer.
3. Central-mixed concrete
Central-mixed concrete is also known as a central batching plant where the concrete is closely mixed before transferring into the truck mixer. The plant is also mentioned as wet-batch or pre-mix plants. While sending the concrete by using the truck mixer acts as deconcert only. Sometimes, when the workability requirement is less or the lead is less, distressing units or dump trucks can also be utilized.
Advantages of Ready Mixed Concrete:
The advantages of rmc are as follows:
1. The more durable structure is provided, thus increasing the service life and conserve the life cycle costs.
2. The small or large amount of concrete as per the specification is transferred timely at the site.
3. Petrol and diesel used are less thus noise and air pollution is decreased.
4. The concrete combined is utilized with high versatility. It is put by the following best concrete placing methods.
5. Cement saving will preserve energy and resources.