What is BS EN 451‑1 - Free calcium oxide content in fly ash about?
BS EN 451 is a series of the European standard on testing fly ash to improve the quality and durability of concrete products.
BS EN 451‑1 is the first part of the BS EN 451 series of documents that specifies the procedure for the determination of free calcium oxide content in fly ash.
BS EN 451‑1 specifies the reference procedure. If other methods are used it needs to be shown that they give results equivalent to those obtained by the reference method.
Who is BS EN 451‑1 - Free calcium oxide content in fly ash for?
BS EN 451‑1 on testing fly ash is useful for:
- Manufacturers of concrete and concrete products
- Calcium manufacturers and suppliers
- Personnel of the laboratory to test calcium oxide content
Why should you use BS EN 451‑1 - Free calcium oxide content in fly ash?
The use of fly ash in cement concrete has many benefits and improves concrete performance in both the fresh and hardened states.
BS EN 451‑1 navigates you through the procedure for determining the free calcium oxide content of the sample.
The standard deviations of repeatability and reproducibility of calcium oxide are determined in BS EN 451‑1.
BS EN 451‑1 provides the apparatus and reagents requirements of analytical grade and distilled water or water of equal purity.
BS EN 451‑1 provides the test procedure for preparation of sample and determination and calculation of the free calcium oxide content of the dry fly ash.
Furthermore, BS EN 451-1 can help you determine the fly ash that is used in concrete, which improves the workability, strength, and durability of hardened concrete while decreasing crack problems and permeability to water and hostile chemicals.
As a result, you get concrete with major environmental benefits, as well as concrete that extends the life of concrete structures by boosting concrete strength and durability.

