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

This paper presents the results of an investigation dealing with the reduct ion in water demand of the non-air-entrained concrete incorporating large v olumes of ASTM Class F and C fly ashes. The eight fly ashes investigated we re from Canada and the USA, and the percentage replacement of fly ash in co ncrete was 55% by mass of Portland cement. No superplasticizer was used in the concrete mixtures. The test results show that the reduction in water de mand of the concrete incorporating the fly ashes ranged from a low of 8.8 f or Lingan fly ash from Nova Scotia, Canada to a high of 19.4% for Coal Cree k fly ash from the USA. The 1-day compressive strength of the concrete rang ed from 6.3 MPa for fly ash from Belews Creek, USA to a high of 13.9 MPa fo r fly ash from Thunder Bay, Canada. The 28-day compressive strength of the concrete ranged from 30.7 to 55.8 MPa. (C) 2000 Elsevier Science Ltd. All r ights reserved.