Concrete hardens through a chemical reaction that occurs when its key components are mixed together.
When the necessary materials for concrete are combined – specifically cement, aggregate, and water – a significant process begins. As stated in the provided reference:
"When the constituents of concrete (cement, aggregate and water) are brought together, the cement and water chemically react and eventually set to form a hard mass which adheres to and binds together the aggregates to form concrete."
This chemical reaction between cement and water is the fundamental mechanism that causes concrete to transition from a liquid or plastic state to a solid, hard mass.
The Process of Concrete Hardening
The hardening process, based on the referenced information, can be broken down into key stages:
- Mixing Constituents: The raw materials – cement, aggregate (like sand and gravel), and water – are combined.
- Chemical Reaction: The cement and water immediately begin to chemically react with each other.
- Setting: This chemical reaction causes the mixture to gradually lose its plasticity and set, forming a solid, hard mass.
- Binding: This resulting hard mass acts as a binding agent. It strongly adheres to and ties together the aggregates distributed throughout the mixture.
Key Interactions
The hardening relies primarily on the interaction between two components:
| Component | Role in Hardening Process |
|---|---|
| Cement | Reacts chemically with water. |
| Water | Reacts chemically with cement, enabling hardening. |
| Aggregate | Bound together by the resulting hard mass. |
The hard mass created by the cement-water reaction is what gives concrete its strength and structural integrity, effectively cementing the aggregates into a solid composite material.
