1. Lect., Concrete Technol. Unit, Dept. of Civ. Engrg., Univ. of Dundee, Nethergate, Dundee, DD1 4HN, U.K.
2. Prof. and Dir., Concrete Technol. Unit, Dept. of Civ. Engrg., Univ. of Dundee, Nethergate, Dundee, DD1 4HN, U.K. E-mail: r.k.dhir@ dundee.ac.uk