Introduction
RMC refers to Ready-Mix Concrete, a specially made concrete mixture which is produced at batching plants and delivered directly to building sites in the form of ready product. For several reasons, it is vital in construction. Second, RMC reduces the risk of structural flaws through consistency in concrete quality and strength. Second, it saves time and labor costs by avoiding the need to mix on-site. Third, RMC provides for the precise control of cement proportions and is well suited to different construction applications. Lastly, it increases durability and cuts waste, making it an environmentally responsible choice.
How RMC is Made and How many types Rmc of Plants
Ready Mix Concrete (RMC) plants are classified into several types based on their layout and the mechanism by which the mixed concrete is transported to the construction site. Here are the common types of RMC plants:
Dry Batch RMC Plant
In dry batch concrete plants, all the ingredients except for water are mixed. The dry mix is then discharged into a concrete transport truck where water is added to the mix. This type of plant is suitable where the concrete batching plant and the construction site are far from each other.
Wet Batch RMC Plant
Also known as a central mix plant, all the ingredients including water are mixed at the plant. This mixed concrete is then transported to the construction site in a transit mixer that keeps the concrete in motion to prevent setting.
Mobile RMC Plant
These are compact, portable plants that can be easily transported from one construction site to another. They are suitable for construction projects that require frequent changes in site locations.
Stationary RMC Plant
These plants are set up for long-term use at a single location and are capable of producing high volumes of RMC. They are ideal for large construction projects with long durations.
Modular RMC Plant
A modular plant is one that is made up of separate modules or units that can be combined to create a larger plant. These plants offer the flexibility of adding or removing modules according to the project requirements.
Custom-built RMC Plant
Some RMC plants are custom-built to meet specific project needs. These can vary greatly in terms of capacity, layout, and equipment used.
Each type of RMC plant has its own advantages and is chosen based on the specific needs of the construction project, such as the quantity of concrete required, the nature and duration of the project, and the distance to the construction site.
Central Mix Plant: Step-by-Step Production Process
Central Mix Plants, also known as wet RMC plants, are where the concrete is produced in a controlled environment at a concrete batching plant. The following is a step-by-step description of the production process:
Storage of Materials
All the raw materials (coarse aggregates, fine aggregates, cement, and, if used, fly ash) are stored separately. Aggregates are usually kept in different bins, cement and fly ash in silos, and admixtures in tanks.
Batching
The process begins with the batching of the raw materials, which involves measuring the quantities of aggregates, cement, fly ash, and admixtures according to the specific mix design.
Mixing Ratio
The mix ratio of RMC is determined based on the structural requirements and can vary significantly. The mix design specifies the ratio of cement to sand to aggregates and the amount of water and admixtures needed.
Weighing and Mixing
Each material is weighed to ensure accuracy. Water and admixtures are measured and added to the mix to increase workability and modify setting times or strength. The materials are discharged into a concrete mixer truck in a specific order, typically starting with a portion of the water, followed by aggregates, cement, and then the remaining water and admixtures.
Mixing
The concrete is mixed in the drum of the mixer truck while it rotates. This ensures that the concrete is homogenous and that the aggregates are evenly coated with the cement paste.
Quality Control
Throughout the process, quality control measures are in place to ensure that the RMC meets the desired specifications and standards.
Transport
The mixed concrete is then transported to the construction site in the mixer truck, which continues to rotate to keep the concrete in a workable state.
Delivery
Upon arrival at the construction site, the RMC is offloaded. The timing is crucial as the concrete must be used before it begins to set.
Placement
Once delivered, the concrete is placed into the forms or molds as quickly as possible.
Curing
After placement, the concrete must be properly cured to achieve the desired strength and durability.
RMC plants use sophisticated equipment and consistent methods to ensure that the concrete produced meets the specific requirements for different construction applications. The use of RMC is preferred for its quality, convenience, and speed of construction.
Total cost required to set up at mid size ready-mix concrete (rmc) plant would be around 4.5- 5 crores approximately
Grades of Ready Mix Concrete (RMC):
M-7.5, M-10, M-15, M-20, M-25, M-30, M-35, M-40:
These grades indicate the compressive strength of concrete, measured in N/mm², achieved after 28 days of curing.
“M” stands for Mix, followed by a number representing the concrete’s strength. For instance, M-20 concrete has a strength of 20 N/mm².
The mix includes specific proportions of cement, fine aggregates (like sand), and coarse aggregates (like gravel or crushed stone).
Types of Ready Mix Concrete
Nominal Mix:
Used for grades up to M-25.Ideal for small-scale constructions or where the demand for concrete is not very high.
The proportions of cement, sand, and aggregates in a nominal mix are predefined and not based on extensive testing. They offer a general guideline for mixing but may not provide the highest degree of strength or durability.
Design Mix:
Utilized for higher-grade concretes (M-30 and above).The mix ratios are determined through rigorous lab testing, taking into account various factors such as the workability of concrete, environmental conditions, and the specific properties needed in the finished product.
Design mixes are more precise and tailored for large-scale or critical structures where specific performance characteristics are essential.
This method allows for more control over the quality and performance of the concrete, ensuring it meets the exact requirements of the project.
Application in Construction
Smaller Projects: For residential buildings, pathways, and minor structures, nominal mixes (up to M-25) are usually sufficient.
Larger Projects: For commercial buildings, bridges, dams, and other significant structures where higher strength and durability are paramount, design mixes (M-30 and above) are essential.
Importance in Construction
Quality Control: Ensures that the concrete used in construction meets the required strength and durability standards.
Customization: Different construction projects have varying requirements. The flexibility in concrete grades allows for customization according to specific structural needs.
Safety and Reliability: Higher-grade concrete provides better resistance to environmental factors and loads, enhancing the safety and longevity of structures.
In conclusion, understanding the different grades of RMC and their applications is crucial in the construction industry. It ensures that the right type of concrete is used for each project, aligning with the structural requirements and environmental conditions.
RDC Concrete (India) Pvt Ltd
Background: Established in 1993, RDC Concrete (India) Pvt Ltd has grown to become a leader in the RMC sector in India. The company, with its origins in Singapore, has expanded its operations across various parts of India.
Specialization: Known for its diverse range of concrete mix designs suited for different construction needs, including high-strength concrete and special application concrete.
Geographical Reach: Has a wide network of plants across India, making it a preferred supplier for various types of construction projects.
UltraTech RMC (Aditya Birla Group)
Background: UltraTech Cement manufactures RMC under the UltraTech Concrete brand, known for its quality and durability. Innovation and Technology: Uses state-of-the-art, computerized automatic batching and mixing technology to ensure quality and consistency.
Presence: With over 103 plants across India, UltraTech Concrete has a vast network, catering to both small and large-scale construction projects.
Concrete India
Background: Started in 2006, Concrete India quickly established itself as a quality RMC provider in Bangalore and nearby regions.
Focus on Quality: Emphasizes on providing high-quality concrete mix, tailored to meet the specific needs of each project.
Clientele: Has catered to numerous residential, commercial, and infrastructure projects, earning a reputation for reliability and service excellence.
ACC Limited
Historical Significance: Being the first to set up a commercial RMC plant in India, ACC has been a pioneer in the industry.
Network: With around 57 modern plants in major cities, ACC RMC has one of the most extensive reaches in the country.
Product Range: Offers a wide range of RMC products designed for various applications in construction, from general-purpose concrete to high-performance and specialty mixes.
Unicon ReadyMix
Association: As a part of CI CONCRETE INDIA PRIVATE LIMITED, Unicon Ready-Mix benefits from extensive experience and expertise in the concrete industry.
Customization: Specializes in custom mix designs, catering to specific project requirements.
Growth and Expansion: Has expanded its operations significantly since its inception, serving a wide range of clients in the construction sector