AASHTO M 295-21 PDF Download

The AASHTO M 295-21 standard defines the requirements for using coal fly ash and natural pozzolan in concrete applications. The standard specifies that these materials should exhibit cementitious or pozzolanic action, or both, in order to contribute to the desired properties of the concrete.

The specification covers both coal fly ash, which is a byproduct of the combustion of pulverized coal in power plants, and raw or calcined natural pozzolan, which are naturally occurring materials with similar properties. The standard recognizes that these materials may be used in concrete to achieve different objectives, such as enhancing cementitious or pozzolanic reactions, or improving other specific characteristics.

By providing clear guidelines for the use of coal fly ash and natural pozzolan in concrete, the AASHTO M 295-21 standard ensures that these materials meet the necessary performance and quality requirements. This allows engineers and concrete producers to make informed decisions about incorporating these materials into their concrete mixtures, with the aim of achieving desired properties and optimizing performance.