Multifunctional cork – alkali-activated fly ash composites: A sustainable material to enhance buildings’ energy and acoustic performance

• Published in: Energy and buildings Vol. 210; p. 109739
• Main Authors: Novais, Rui M., Carvalheiras, João, Senff, Luciano, Lacasta, Ana M., Cantalapiedra, Inma R., Giro-Paloma, Jessica, Seabra, Maria P., Labrincha, João A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.03.2020; Elsevier BV
• Subjects: Absorption; Acoustic absorption; Alkali activation; Building materials; Buildings; Bulk density; Carbon dioxide; Carbon dioxide emissions; Composite; Composite materials; Construction; Construction industry; Construction materials; Cork; Energy conservation; Environmental regulations; Fly ash; Foams; Heat conductivity; Heat transfer; Humidity; Moisture buffer value; Pollution control; Sound; Sound transmission; Sustainability; Sustainable materials; Thermal and acoustic insulation; Thermal conductivity; Moisture buffer value; Composite; Thermal and acoustic insulation; Cork; Alkali activation
• ISSN: 0378-7788; 1872-6178
• DOI: 10.1016/j.enbuild.2019.109739

•Multifunctional alkali-activated composites were synthesised for the first time.•The composites were produced using a natural and sustainable aggregate (cork).•Their thermal conductivity is amongst the lowest ever reported for AAM.•They show excellent sound absorption ability and good moisture buffering capacity.•The multifunctional properties set them apart from conventional building materials. This work evaluates, for the first time, the possibility of producing multifunctional alkali-activated composites combining ultra-low density, low thermal conductivity, high acoustic absorption, and good moisture buffering capacity. The composites were prepared using cork as a lightweight aggregate. This novel material might promote energy savings and tackle the CO2 emissions of the building sector, while simultaneously improve the comfort for inhabitants (e.g. humidity levels regulation and sound pollution reduction). The composites apparent density (as low as 168 kg/m3) and thermal conductivity (as low as 68 mW/m K) are amongst the lowest ever reported for alkali-activated materials (AAM) composites and foams, while their sound absorption ability is comparable to the best performing AAM foams reported to date, but in addition these eco-friendly composites also show good ability to passively adjust the humidity levels inside buildings. The multifunctional properties shown by the cork – AAM composites set them apart from other conventional building materials and might contribute to the global sustainability of the construction sector. [Display omitted]