External sulfate attack in dam concretes with thaumasite formation
Concrete core samples extracted from different areas of the Mequinenza Dam (Spain) have been studied and expansive reactions affecting the structure were not found. However, expansive reactions in the concrete of certain parts located near the abutments of two galleries have been observed as a conse...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/27227 |
| Acceso en línea: | https://hdl.handle.net/2117/27227 https://dx.doi.org/10.3989/mc.2015.10513 |
| Access Level: | acceso abierto |
| Palabra clave: | Thaumasite Concrete dams Mequinenza (Spain) Concrete dam Sulfate attack DELAYED ETTRINGITE FORMATION GYPSUM FORMATION CEMENT MORTARS IRON SULFIDES DETERIORATION PERFORMANCE OXIDATION SYSTEM MODEL Sulfats Preses de formigó Mequinensa (Catalunya : Pantà) Àrees temàtiques de la UPC::Enginyeria civil::Materials i estructures::Materials i estructures de formigó |
| Sumario: | Concrete core samples extracted from different areas of the Mequinenza Dam (Spain) have been studied and expansive reactions affecting the structure were not found. However, expansive reactions in the concrete of certain parts located near the abutments of two galleries have been observed as a consequence of an external sulfate attack due to the sulfur compounds contained in the lignites that are present on the surrounding terrain. Secondary gypsum, ettringite, and thaumasite, as well as several sulfate efflorescence have been detected. The thaumasite formed in the degraded concrete is related to a Thaumasite Sulfate Attack (TSA). Scanning Electron Microscopy (SEM) and Rietveld analyses of the TSA samples would show that thaumasite could have been formed thanks to ettringite acting as nuclei or by a direct precipitation from solutions within the pores of the cement matrix. |
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