The authors would like to thank Professor G. C. Wood of the Corrosion and Protection Centre for providing research facilities and to the Science Research Council's North Western Universities Consortium fbr Marine Technology;
for' financial assistance. They would also like to thank Dr. R. A. Cottis of the Centre;
and Dr R. A. King of the Centre's Industrial Services (CAPCIS);
for their valuable ideas and suggestions;
and Mr J. Bowler;
of the Civil Engineering Department;
UMIST;
for;
·his;
-;
stance in the preparation of the concrete samples;