ABSTRACT
The content of f-CaO in high calcium Fly Ash (FA) produced by Kaiyuan Xiaolongtan Power Station reached at 9.32% and that of SO3 was higher than the state criterion. The content of f-CaO and SO3 can be effectively reduced by blending Ground Sand Dust (GSD) with FA, so the illegibility of cement soundness can be avoided. The study showed that: 1) ground in trial ball mill for 60 min, the river sand can be made into GSD with fineness (45 μm) of 12.8% and the specific surface area of 12,656.44 cm2/g; 2) while GSD was blended with FA, the 28d compressive strength declines with the dosage of GSD was added; 3) cement soundness was up to state criterion when the blending rate of GSD ranges from 20 to 50% in the mineral admixture; 4) GSD ground for 60 min had the best performance in C18020 RCC; 5) as to the different GSD blending rates, 30% was the best with only a 5.4% loss of 90d compressive strength; and 6) due to the lower proportion of SD in river sand, the workability and density of concrete is poor. The performance of the concrete can be evidently improved if 10% sand was replaced by GSD. The 90d compressive strength can also be increased by 35.5%.
