Fly Ash in Cement and Concrete

This review of the literature on fly ash was prepared to identify problems and research opportunities concerning the characterization of fly ash for its use with portland cement in concrete. The focal points of this work are (1) the physical and chemical characteristics of fly ashes and the methods used to determine them, and (2) the interactions between portland cements and fly ashes in fresh and hardening mixtures and how these interactions are affected by the characteristics of the fly ashes. The objectives of this study are (1) to provide the reader with a good summary of the technical literature on fly ash, (2) to show both the adequact and the limitations of current test methods and specifications to assure predictable and improved performance of fly ash with cement in concrete, and (3) to identify research needs.