Pathologies and biological growths on concrete dams in tropical and arid environments in Argentina

Concrete pathologies found in two dams, in tropical and arid environments, were compared in order to assess their origin and possible influence on the biological deterioration processes caused by the organisms growing on these structures. Compression resistance and water absorption tests were performed on concrete samples, as well as Optical and Scanning Electron Microscopy observations and Electron Dispersion Spectrometry analyses. Organisms were studied under stereoscopic and optical microscope and determined with keys. It has been observed that cement samples from both dams had a low compression resistance and high absorption rates attributed to high porosity. Mosses and diatoms were found on the tropical area dam whereas these biological growths seemed to be absent in the dam of the dry area. Since both dams have had similar erosion problems, pathologies could be attributed to the poor quality of materials easily eroded by flowing water. As for the presence of mosses and diatoms, they seemed to have little influence in the damage.