Title: Concrete Durability Specification by Water/Cement or Compressive Strength for European Cement Types

Author(s): A. P. Barker and J. D. Matthews

Publication: Symposium Paper

Volume: 145

Issue:

Appears on pages(s): 1135-1160

Keywords: carbonation; cement types; compressive strength; concretes; durability; fly ash; freeze-thaw durability; limestone; permeability; slags; specifications; strength; water-cement ratio; Materials Research

DOI: 10.14359/4433

Date: 5/1/1994

Abstract:
The European prestandard for concrete, ENV 206, includes durability requirements framed principally in terms of maximum water-cement values for various exposure classes. Minimum cement contents are also given, but the values are relatively low. No minimum concrete strength grades are included, and no distinction is made between cements of different strength classes or different types. It is clear that the variety of cement types specified in the European prestandard for cement, ENV 197-1, will produce a wide range of concrete strengths when fulfilling the limiting specification requirements for a given exposure category. Previous work has suggested that, although water-cement ratio may be the most suitable specification parameter within a single cement type, strength should also be specified if comparable concrete durability is to be achieved with a range of cement types. To test this proposition, two series of concrete mixes were prepared with a variety of cements, including slag, fly ash, and limestone filler: one series had equal cement contents and water-cement-ratio and the other had equal strength grade and workability. The results to date show that durability, as measured by permeability, carbonation, and freeze-thaw resistance, is not equal for all cements at the same water-cement ratio, and suggest that concrete strength grade is a better specification parameter if similar durability is required from the wide range of cement types defined in ENV 197-1.