Comparing Compressive Strength of Alkali-Activated Coal Fly Ash to Natural Pozzolans

Words: Bronzella Cleveland

ASTM International Committee C01 on Cement is developing a proposed standard that will be used to help create data for comparing the compressive strength of alkali activated fly ash and natural pozzolans.

ASTM WK42602, Test Method for Compressive Strength of Alkali Activated Coal Fly Ash and Raw or Calcined Natural Pozzolan Cement Mortars (Using 2-inch or [50 mm] Cube Specimens), is under the jurisdiction of Subcommittee C01.13 on Special Cements.

"Once approved, ASTM WK42602 may be applied to compare different lots or sources or to monitor changes in strength given by a single source of fly ash or natural pozzolan," says Dr. Ivan Diaz-Loya, research engineer, CERATECH Inc., and a member of C01 and C09 on Concrete and Concrete Aggregates. Fly ash-based binders are used in a wide range of construction projects, including precast, roller-compacted and ready-mix concrete.

According to Diaz-Loya, primary users of ASTM WK42602 will be producers of construction materials, independent testing laboratories and academic research groups. "The proposed standard will help alkali activated materials to gain acceptance in the marketplace by making it easier to ensure that consumers are provided with a quality product," says Diaz-Loya. "It will also help to validate and compare results between different research groups."

Diaz-Loya says C01.13 hopes that the development of ASTM WK42602 will lead to further test methods, practices and specifications for the material covered. Interested parties involved in the research or production of alkali activated fly ash or natural pozzolan products are invited to join in the ongoing development of ASTM WK42602.

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