Concrete lambda: density and thermal conductivity
Concrete has no universal lambda: density, aggregate and moisture conditions matter. A historical generic ready-mixed concrete EPD lists 1.6 W/(m·K) and gross density 2380 kg/m³. This document example is not a current supplier declaration or an automatic value for reinforced or lightweight concrete. Concrete volume and thermal conductivity are different inputs.
The Concrete Centre — generic ready-mixed concrete EPD. Product-specific or historical example; verify current conditions.
Document examples, not design defaults
| Product / source | λ [W/(m·K)] | Scope |
|---|---|---|
| The Concrete Centre — generic ready-mixed concrete EPD | 1.6 | Product-specific or historical example; verify current conditions |
Check before using λ
- Record the exact product, market, density or thickness and document revision.
- Distinguish declared λD from the design value for the intended moisture and temperature. Unit conversion does not perform this correction.
- Confirm thickness in metres and use the same material conditions throughout the calculation.
From lambda to layer R
R [m²·K/W] = d [m] / λ [W/(m·K)]
For an illustrative 200 mm layer at the EPD value 1.6 W/(m·K), R = 0.20 / 1.6 = 0.125 m²·K/W. Doubling thickness to 400 mm gives 0.250. This layer resistance describes heat transfer; the volume needed for ordering concrete is a separate geometric calculation.
| d [m] | λ [W/(m·K)] | R [m²·K/W] |
|---|---|---|
| 0.20 | 1.6 | 0.125 |
| 0.40 | 1.6 | 0.250 |
Interpretation and source limits
The cited ready-mixed concrete EPD cannot supply a lightweight-concrete or reinforced-member value automatically. Match density, aggregate and moisture, then assess reinforcement and bridges separately.
Read declared and design thermal valuesMaterial lambda references
Sources and verification scope
The Concrete Centre generic ready-mixed concrete EPD is a historical document example: 1.6 W/(m·K) at gross density 2380 kg/m³. Use a current declaration for the concrete actually supplied.