Evaluation of the state of structural elements of the Legazpi Market: Attack by sulphates on concrete and corrosion of reinforcements

The work describes the methodology used to study the concrete of pillars, supports and foundations of several zones of the Mercado de Legazpi in Madrid (Spain). The soils where the latter are buried have also been analyzed. A visual inspection together with an Ultrasonic characterization has allowed the selection of samples for subsequent laboratory analysis by X-Ray Diffraction and Scanning Electron Microscopy, as well as quantification of chlorides and sulphates. Corrosion of reinforcements have been found in specific areas, which are due both to the previous use of the structure and its aging. There is also a significant amount of sulfates in the soil, of anthropogenic origin, which would explain the formation of sulphate attack products in the foundations. However, this attack does not seem to be a significant decrease in the integrity of the structure.