Reduction in water demand of non-air-entrained concrete incorporating large volumes of fly ash

摘要

This paper presents the results of an investigation dealing with the reduction in water demand of the non-air-entrained concrete incorporating large volumes of ASTM Class F and C fly ashes. The eight fly ashes investigated were from Canada and the USA, and the percentage replacement of fly ash in concrete was 55 percent by mass of Portland cement. No superplasticizer was used in the concrete mixtures. The test results show that the reduction in water demand of the concrete incorporating the fly ashes ranged from a low of 8.8 for Lingan fly ash from Nova Scotia, Canada to a high of 19.4 percent for Coal Creek fly ash from the USA. The 1-day compressive strength of the concrete ranged from 6.3 MPa for fly ash from Belews Creek, USA to a high of 13.9 MPa for fly ash from Thunder Bay, Canada. The 28-day compressive strength of the concrete ranged from 30.7 to 55.8 MPa.