There are two main reasons for investigating and testing concrete: to check compliance with a specification during construction, and to investigate performance after a period in service. The Concrete Society has been actively involved in both of these areas since its formation nearly 20 years ago and has contributed, directly and indirectly, to the revision and improvement of many British Standards. During the 1960s and 1970s the main emphasis was on improving testing procedures related to compliance checking and, in particular, on establishing clear guidelines on procedures for compressive strength testing of cubes.