Center for By-Products Utilization SUPERPLASTICIZES STRUCTUREAL CONCRETE CONTAINING HIGH VOLUMES OF CLASS C FLY ASH

This research is conducted with a view to investigate performance of concrete containing high volumes of ASTM Class C fly ash. A portland cement concrete, proportioned to have 28-day compressive strength of 6,000 psi (41 N4Pa) is used in this study. Concrete mixes are also proportioned to have various levels of cement replacement by fly ash ranging from 40% to 70% by weight. Concrete performance is evaluated with respect to compressive strength tensile strength and modulus of elasticity. At a 28-day age, concrete containing fly ash consistently shows higher compressive strength compared to the no-fly ash concrete. Analysis of results shows that ASTM Class C fly ash could be substituted for cement replacements up to 70% to achieve design compressive strength levels greater than 6,000 psi (41 MPa).