Véronique Baroghel-Bouny is Deputy Head in charge of International of the "Materials and Structures" Department at Université Gustave Eiffel, France. Her research field covers the physical and chemical properties of cement-based materials, innovative materials, and SCM-concretes, at early age and in the long term, in particular their microstructure and durability. She has published more than 80 papers and leads several working groups, in particular within the framework of the French and European Committees of Standardization.Esperanza Menéndez (deceased) was Head of the Physical-Chemical Test Unit of the IETcc at Spanish National Research Council (CSIC) in Madrid, Spain. She was a respected member of the international scientific community. Her expertise was in physico-chemical characterization of cement-based materials, durability and degradation of concrete, such as alkali-aggregate reaction and behaviour in aggressive aqueous environments, in particular the resistance to acid or sulfate attacks.Manu Santhanam is Surendra and Dorothie Shah Chair Professor in the Dept. of Civil Engineering, IIT Madras, India. His research domains cover cement chemistry and multi-scale characterization of concrete including non-destructive testing, assessment of deterioration mechanisms in concrete and masonry structures, 3D printing of concrete structures, concrete durability and use of supplementary cementing materials. He has co-authored more than 150 journal publications and about 100 conference papers on construction material properties and performance.

• Introduction.- Review of Sulfate Attack Mechanisms.- External sulfate attacks in the field.- Review of existing lab test methods for External Sulfate Attacks and recommendations for an improved testing methodology.