Role of cement content in specifications for concrete durability: cement type influences

In this paper, which describes part of a major investigation, the role of cement content in specifications for concrete durability is examined. The main cements considered were (a) Portland cement (PC; CEM I), (b) PC/30% PFA (CEM II/B-V) and (c) PC/50% GGBS (CEM III/A), while other BS EN 197-1 cements were tested selectively. Concretes of fixed w/c ratio (w/(PC + addition) ratio), but with cement contents varying around the minimum values given in standards were evaluated. The workability of concrete with low cement and water contents was controlled with a superplasticiser and the fines content was maintained by the use of ground limestone as a filler. Tests were carried out to examine these effects on the fresh, engineering, permeation and durability properties of concrete. The results show that at fixed w/c ratio, reduction in cement content by up to 22% had no adverse effect on most concrete properties and, if anything, gave some improvement. The various cement types and combinations tested had little ...