n August 1991 the Canada Centre for Mineral and Energy Technology (CANMET) in association with the American Concrete Institute; the Institute for Research in Construction/ National Research Council, Ottawa; and the Eastern Ontario and Quebec Chapter of American Concrete Institute sponsored the 2nd CANMET/ACI International Conference on Durability of Concrete. More than 100 papers from 20 countries were received and peer reviewed in accordance with the policies of the American Concrete Institute. Seventy were accepted for publication. The accepted papers are published in two volumes.