BRE IP15/00 PDF

Introduction

Water reducing admixtures (WRAs) in concrete offer a number of potential benefits to the construction process and to the long term performance of concrete. Although WRAs are widely used in many UK construction projects, their benefits are less widely recognised in the UK than in continental Europe. There are two main reasons for this.

• The relatively high minimum cement content requirements in UK Codes and Standards can reduce the incentive to use WRAs, unless they are needed to meet conflicting mix requirements; for example, strength grade, maximum water/cement (w/c) ratio and workability.

• Because of a perceived higher cost for increased workability, there is a tendency in the UK to specify concrete with a lower workability than that specified elsewhere in Europe.