What is Ready Mixed Concrete?
Ready mixed concrete is a pre-prepared type of concrete that is particularly beneficial when small quantities or intermittent placement of concrete are required. It is also ideal for large-scale projects where space is limited and there isn't enough room for a mixing plant and aggregate stockpiles. Ready mixed concrete is produced in a central plant and then delivered to the construction site, ensuring consistency and quality.
Types of Ready Mixed Concrete
There are three main types of ready mixed concrete:
1. Transit Mixed (Truck-Mixed) Concrete
In transit mixed concrete, materials are batched at a central plant and are mixed either partially or completely in the truck during transit. The concrete is often mixed fully at the job site. This method keeps the water separate from the cement and aggregates, preventing premature hardening and ensuring the concrete is fresh when it arrives at the site. Transit mixing allows for longer haul distances and ensures flexibility during transportation, but the truck capacity is smaller than with other methods.
2. Shrink Mixed Concrete
Shrink mixed concrete is designed to increase the truck’s load capacity while retaining the advantages of transit mixed concrete. The concrete is partially mixed at the plant to reduce the volume, and then the mixing is completed either in transit or at the job site. This method maximizes truck capacity while still providing the flexibility of transit mixing.
3. Central Mixed Concrete
Also known as central batching or wet-batch concrete, central mixed concrete is thoroughly mixed at the plant before being loaded into the truck. In this method, the truck mixer acts solely as an agitator, not a mixer. This ensures that the concrete is fully mixed and ready to use when it arrives at the job site.
Benefits and Considerations
- Remixing: Upon arrival at the construction site, ready mixed concrete is often remixed to ensure the proper consistency and workability. However, concrete that has been remixed tends to set faster than concrete mixed only once.
- Additives: Additional materials like water and additives can be added at the job site to achieve the required properties before placement, ensuring the optimal mix quality.
Ready mixed concrete provides the convenience of high-quality, consistent concrete that can be delivered directly to job sites, making it a preferred choice for both small and large-scale construction projects.
