Design and characterization of geopolymer foams reinforced with Miscanthus x giganteus fibres

Katharina Walbrück; Steffen Witzleben; Dietmar Stephan

doi:10.1016/j.heliyon.2024.e35947

Design and characterization of geopolymer foams reinforced with Miscanthus x giganteus fibres

Heliyon. 2024 Aug 8;10(16):e35947. doi: 10.1016/j.heliyon.2024.e35947. eCollection 2024 Aug 30.

Authors

Katharina Walbrück¹, Steffen Witzleben¹, Dietmar Stephan²

Affiliations

¹ Department of Natural Sciences, Bonn-Rhine-Sieg University of Applied Sciences, von-Liebig-Str. 20, 53359, Rheinbach, Germany.
² Building Materials and Construction Chemistry, Department of Civil Engineering, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355, Berlin, Germany.

Abstract

This paper presents the results of the optimisation and characterization of Miscanthus fibre reinforced geopolymer foams based on fly ash and represents an important step forward in the development of a sustainable and environmentally friendly insulation material. Miscanthus belongs to a promising group of renewable raw materials with favourable thermal insulation properties. Design of experiment (DoE) were used to optimize the thermal conductivity and compressive strength of Miscanthus x giganteus reinforced geopolymer foams. In addition, the samples was analyzed using X-ray diffraction (XRD), Field emission scanning electron microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR). Mixtures with a low thermal conductivity of 0.056 W (m K)^-1 and a porosity of 79 vol% achieved a compressive strength of only 0.02 MPa. In comparison, mixtures with a thermal conductivity of 0.087 W (m K)^-1 and a porosity of 58 vol% achieved a compressive strength of 0.45 MPa. Based on the determined parameters especially due to the low compressive strength, an application as cavity insulation or insulation between rafters is possible.

Keywords: Compressive strength; Geopolymer foams; Miscanthus x giganteus; Porosity; Thermal conductivity.