Title: Use of Natural Pozzolans in Concrete (ACI 232.1R)
Author(s): ACI Committee 232
Publication: Materials Journal
Appears on pages(s): 410-426
Keywords: alkali-silica reaction; calcined shale; cement; concrete; concrete strength; diatomaceous earth; lime; natural pozzolan; pozzolan; pozzolanic activity; sulfate attack (on concrete); volcanic ash; Materials Research
This state-of-the-art report provides a historical background on the use of natural pozzolans during the past 3000 years, and an overview of the properties of natural pozzolans and their proper use in the production of portland-cement concrete. Natural pozzolans mixed with lime were used in concrete construction long before the invention of portland cement because of their contribution to strength of concrete and mortar. Today, natural pozzolans are used with portland cement not only to contribute to strength, but also for economy and beneficial modification of certain properties of fresh and hardened portland-cement concrete. The report contains information and recommendations concerning the selection and use of natural pozzolans generally conforming to the requirements of ASTM C 618. Topics covered include the effect of natural pozzolans on concrete properties, a discussion of quality control and quality assurance, and guidance regarding handling and use of natural pozzolans in specific applications. References are provided that offer more information on each topic.