What is the composition of ready mix concrete?
Ready-mix concrete is fundamentally a carefully proportioned mixture of paste and aggregates.
According to the provided reference, ready-mix concrete consists of two primary components:
- Paste: This is the binder that holds the concrete together.
- Aggregates: These are granular materials that make up the bulk of the concrete.
Let's delve a little deeper into each component.
The Paste: Cement and Water
The paste component of ready-mix concrete is specifically composed of:
- Portland Cement: This is the crucial ingredient that reacts with water to form a binding agent.
- Water: Water is necessary for the chemical reaction with cement and to make the mixture workable.
As the reference states, this paste coats the surface of the fine and coarse aggregates.
The Aggregates: Fine and Coarse
Aggregates provide volume, stability, and strength to the concrete. They are typically categorized into:
- Fine Aggregates: Usually sand.
- Coarse Aggregates: Typically gravel or crushed stone.
These materials are selected based on their size, shape, and durability to achieve the desired concrete properties.
The Hardening Process: Hydration
The transformation of the liquid mixture into solid concrete is driven by a chemical reaction called hydration. This reaction occurs between the Portland cement and water in the paste. As the reference explains, hydration causes this paste to harden and gain substantial strength, forming the rock-solid mass commonly known as concrete.
Understanding this composition is key to producing concrete with the desired properties for various construction applications.
