The investigation of the validity of a single k-value for fly ash in the range of W/C ratio critical for the standards

Abstract

The prescriptive k-value of the standards should cover a range of W/C ratio in fly ash concretes. This range corresponds to the requirements for the environmental exposure classes. The results of the present study showed a significant decrease of the k-value at low W/C ratio for compressive strength. The k-values measured at 0.60, 0.50 and 0.40 - W/C ratios enabled safer results. The durability performances of the FA concretes were generally better. The equivalent W/C ratios (and effective k-values) were considerably different from the nominal ones. The results indicated that the performance-based k-values could be more reliable than the prescriptive k-value. (C) 2020 Elsevier Ltd. All rights reserved.