Ready Mixed Concrete is an ideal concrete that is manufactured in a factory or in a batching plant based on standard required specifications.
The finished concrete mixture is then transported to the worksheet within the transit mixer above the truck.
Ready Mix Concrete saves time and gives proper strength, where the traditional concreting method takes a long time for constructing large projects.
This type of concrete assures high durability and stability.
Types of Ready Mixed Concrete:
Transit Composite Concrete:
It is also called dry-batch concrete because all the essential components are immediately charged in the truck mixer.
The mixer drum is quickly rotated at the charging speed during the loading and after it is rotated at conventional mixing speed.
In such ready-mix concrete, three types of adjustments are also possible.
Shrink Mixed Concrete:
The concrete is partially mixed in the plant mixer and partially mixed in truck-mounted drum mixer during transit time.
The amount of mixture within the transit mixer depends on the amount of mixture carried out at the central mixing plant.
Tests need to be performed to establish the need for mixing of drum mixers.
Central Mixed Concrete:
It is also known as a central batching plant, where the concrete is added accurately before loading into a truck mixer; they are also called as wet-batch or pre-mixed plants.
Sometimes, non-agitating units or dump trucks will also be used, when reasonableness is required or leads are low.
The material used in Ready Mixed Concrete:
They are important materials in concrete; they occupy 70–80% of the volume of concrete
The aggregates are divided into two categories by consideration of size:
• Coarse aggregate
• Fine aggregate
Aggregates bigger than 4.75 mm are considered as coarse aggregate, with a dimension of 4.75 mm and less which is considered a fine aggregate.
Cement is composed of four main compounds: Dicalcium Silicate (2Ca0 Si.), Tricalcium silicate (3Ca0 Si02), Tricalcium aluminate (3Ca0 Al203), Tetra-Calcium aluminoferrite (4Ca0 Al203 Fe203).
These compounds are designated as C2S, C3S, C3A, and C4AF, where C stands for calcium oxide (lime), S for silica, and A for alumina and iron oxide.
Small quantities of alcohol and magnesia are additionally present, as well as minor quantities of alkalis and other elements.
The coal used in plants is mainly composed of combustible elements such as carbon, hydrogen and oxygen and non-combustible impurities (from 10 to 40%) commonly present as clay, shale, quartz, feldspar and limestone.
The size of fly ash ranges from 1.0 to 100 microns and the average size is about 20 microns.
The pH value of water should be between 6.o and 8.o according to IS 456-2000.
Advantages of ready mixed concrete:
- Quality concrete is obtained as a ready-mixed concrete mix plant that uses advanced equipment and stationary methods.
- There is strict control over material testing, process constraints and continuous monitoring are the key practices throughout the construction.
- In the case of site mix concrete, poor management over the enter materials, batching and mixing methods are resolved within the ready mix concrete methodology.
- In the construction works to be adopted within the ready mix concrete plant, the speed after the mechanical operation is fixed.
- The output from the site combines the concrete plant using an 8/12 mixer which is 30–60 metric cubes per hour to four to five metric cubes per hour within the ready mix concrete plant.
- Better handling and proper mixing will help in reducing cement consumption by 10 – 12%.
- Also, the use of admixtures and various materials will help in reducing the amount of cement.
- Concrete mixes are used with high versatility; these are the best concrete methods.
- Cement is shielded and dust is minimized because the finished concrete uses a bulk mixture of concrete instead of a bag of cement.
- Conservation of cement will conserve energy and resources; due to low consumption, cement production is low, hence environmental pollution is low.
- Thus an extra durable structure is obtained, which will increase service life and saves costs.
- In the manufacture of ready-mix concrete, there may be much less dependence on human labourers, so the probabilities of human errors are lowered, dependence on intensive labourers also decreases.
- Small or massive quantities of concrete are delivered on time as per specification.
- There has been no delay due to site-based batching plant erection or dismantling; no equipment rental; no depreciation of value.
- Consumption of petrol and diesel is low, hence noise and air pollution are reduced.
Disadvantages of Ready Mixed Concrete:
- Transit time might be a loss of performance from the time of preparation of concrete on the distribution site.
- This will demand additional water or penetration to maintain functionality according to the specification.
- On-site, quality assurance (QA) / quality control (QC) has to test functionality through fatigue testing before being used for manufacture.
- Traffic during the transit of concrete might result in the setting of concrete, so the addition of entrances is required to delay the setting period.
- Formwork and placing arrangements should be prepared in a big area in advance as concrete might be bought in large portions.
Application of Ready Mixed Concrete:
- Retaining wall.
- Pile Foundation.
- Water tank.
- Shear wall.
- Power Plant.
Frequently Asked Questions:
What is meant by ready mix concrete?
Ready Mix Concrete or RMC refers to concrete that is batch or manufactured specifically for construction projects and supplied to the customer as a single product on site.
How much is ready mixed concrete per cubic Metre?
In general, costs between 81.60$ and 106.71 $ per cubic meter.
What is the difference between ready mix concrete and cement?
Cement, usually in the form of powder, acts as a binding agent when mixed with water and aggregates.
Ready-mix concrete is a type of concrete, made in a factory according to a prescribed recipe and then distributed on a worksheet.
Is code for ready mix concrete?
As per Indian Standard code of practice (IS 4926).
The concrete quality produced on the Ready Mixed Concrete plant is extremely according to low deviation orders.
This offers a higher strength of the hardened concrete and the efficiency of the construction at a later date.
RMC operation is extremely mechanized and managed entirely via electronic control and due to this fact reduces the possibility of errors in various tasks.