This paper presents a study on the mechanical properties and durability of concrete made with a high-volume fly ash blended cement using a coarse fly ash that does not meet the fineness requirement of ASTM C 618. The results were compared with those of the HVFA concrete in which unground fly ash had been added at the concrete mixer. The properties of the fresh concrete determined included the slump air content slump loss stability of air content bleeding and setting time; those of the hardened concrete investigated included the compressive strength flexural- and splitting-tensile strengths Youngâ€™s modulus of elasticity drying shrinkage resistance to abrasion chloride-ion penetration freezing and thawing cycling and to de-icing salt scaling. The results show that except for the resistance of the concrete to the de-icing salt scaling the mechanical properties and the durability of concrete made with this blended cement were superior to the concrete in which the unground fly ash and the cement had been added separately at the mixer. The production of HVFA blended cements therefore offers an effective way for the utilization of coarse fly ashes that do not otherwise meet the fineness requirements of ASTM C 618.
This paper was originally published in Cement and Concrete Research Vol. 31 No. 3 Oct. 2001. It includes a list of tables and figures detailing the results of the studies.
Technical Report Author: M.H. Zhang, Nabil Bouzoubaa, V.M. Malhotra, CANMET Energy Technology Centre, Natural Resources Canada,