Description
The primary purpose of this project was to determine the extent to which two fly ashes readily available in Alberta affect the properties of concrete considered for use in bridge works, and accordingly to establish the conditions under which fly ash can safely be specified in such bridge works. The results confirm many potential advantages of using fly ash in air-entrained concrete, including reduced heat of hydration, the option to increase specified strength or reduce the unit volume cost, or some combination of both, particularly in massive bridge components, along with the prospect of satisfactory freeze-thaw durability under moist salt-free exposure conditions, increased resistance to chloride ion penetration, and reduced shrinkage potential. Most of these benefits are realized more fully using a superplasticizing admixture instead of a conventional water-reducing admixture. The main concern and limitation associated with fly ash utilization in bridge works is unsatisfactory...