Evolution of pyrrhotite oxidation in aggregates for concrete

Rocks containing pyrrhotite bands are sometimes used to produce concrete. These rocks oxidize and produce long-term expansive reactions that damage concrete structures, leading to important economic and risk related repercussions. The present study analyses several aspects that affect the oxidation...

Descripción completa

Detalles Bibliográficos
Autores: Oliveira da Silva, Izelman, Pialarissi Cavalaro, Sergio Henrique|||0000-0002-9368-0898, Aguado de Cea, Antonio|||0000-0001-5542-6365
Tipo de recurso: artículo
Fecha de publicación:2014
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:2117/24782
Acceso en línea:https://hdl.handle.net/2117/24782
https://dx.doi.org/10.3989/mc.2014.08413
Access Level:acceso abierto
Palabra clave:Concrete--Deterioration
Sulfates
Iron sulfide
Oxidation
Aggregate
Internal sulfate attack
Dam
Sulfats
Formigó -- Deterioració
Àrees temàtiques de la UPC::Enginyeria civil::Materials i estructures::Materials i estructures de formigó
Descripción
Sumario:Rocks containing pyrrhotite bands are sometimes used to produce concrete. These rocks oxidize and produce long-term expansive reactions that damage concrete structures, leading to important economic and risk related repercussions. The present study analyses several aspects that affect the oxidation process of the aggregate such as the existence of preferential paths for the entrance of the oxidizing agent and the conversion process of the chemical elements involved in the reaction. For that, host rock samples containing pyrrhotite were investigated by scanning electron microscopy and energy dispersive spectroscopy. The results shows that the pyrrhotite appears in bands that create planes of weakness and present cracks that serve as preferential paths for the entrance of oxygen. Furthermore, a new representation is proposed for the oxidation process.