1. Lecturer, Concrete Technology Unit, Division of Civil Engineering, Univ. of Dundee, Dundee DD1 4HN, Scotland, UK (corresponding author).
2. Research Fellow, Concrete Technology Unit, Division of Civil Engineering, Univ. of Dundee, Dundee DD1 4HN, Scotland, UK.
3. Emeritus Professor, Concrete Technology Unit, Division of Civil Engineering, Univ. of Dundee, Dundee DD1 4HN, Scotland, UK.