Triaxial failure behavior of highly porous cementitious foams used as heat insulation

• Autores: Gilka Bötzow, Albrecht; Folino, Paula; Maier, Andreas; Koenders, Eduardus A. B.; Caggiano, Antonio
• Año de publicación: 2021
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: AIR VOIDS; CONCRETE FOAMS; HIGHLY POROUS CEMENTITIOUS COMPOSITES; MECHANICAL CHARACTERIZATION; PORO-(MESO)-STRUCTURE; THERMAL INSULATING PROPERTIES; ULTRALIGHTWEIGHT CONCRETE
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

This work reports a detailed experimental study that is aimed at investigating the failure mechanisms of highly porous cementitious foams used as heat insulation under triaxial stress states. The designed target dry density of the considered foam mixture was 180 kg/m3 by setting the water-to-cement ratio of the considered cement paste to 0.4. The mechanical experiments were accompanied by thermal tests to observe the effect that specific air void structures have on the resulting insulation properties and by micro-to-meso geometric studies to identify and classify the inner structure of the considered mineralized foams. Unconfined compressive strengths were performed first, obtaining peak stresses of 0.252, 0.283, 0.223, and 0.251 (results in MPa), corresponding to peak strains of 39.0, 28.6, 45.3, and 20.6 (in ×10−3 mm/mm), respectively. Moreover, three triaxial confinement levels of 33%, 66%, and 90% of the mean uniaxial compressive strength (fc) were adopted. The results showed that a 33% confinement may cause a strength increase and an almost perfect elastic–plastic stress–strain behavior. However, higher levels of confinements (i.e., 66% and 90%) produced very unstable behaviors in terms of the final strength and stress–strain response.
Fil: Gilka Bötzow, Albrecht. Universitat Technische Darmstadt; Alemania
Fil: Folino, Paula. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina
Fil: Maier, Andreas. Universitat Technische Darmstadt; Alemania
Fil: Koenders, Eduardus A. B.. Universitat Technische Darmstadt; Alemania
Fil: Caggiano, Antonio. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina