The six papers presented here are from the Verbeck Symposium, named in recognition of George Verbeck's long-term studies of sulfate attack. These papers provide valuable new data, answer some critical questions and point toward the work and test methods still needed to better understand sulfate resistance of concrete. Topics include; long-time studies, field experiences and current research on sulfate attack; concrete durability in sulfate soils; physical aspects of sodium sulfate attack; sulfate resistance of cements in a controlled environment.