High-volume fly ash concrete: Analysis and application

Although fly ash as a partial replacement for cement has been utilized for many years, it has been almost exclusively used in low-volume percentages, such as 10 or 20% cement replacement. This paper looks at high-volume percentage replacements from 40 to 70%. A minimix study revealed that 50 and 60% cement replacement percentages were the best candidates for full-scale testing. The environmental benefits included a 25% reduction in smog, human health effects, and fossil fuel use compared to the same element built with a 100% Portland cement mix. The economic benefits included a 15% capital cost reduction and a 20% life-cycle cost reduction when compared with a 100% Portland cement mix. Full-scale testing included a complete mix design in addition to the construction of four concrete infrastructure products. The products built included an alley panel and curb, and gutter sections in the City and County of Denver, a precast manhole and lid, and a twin-tee prestressed girder.