Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 May 22;13(10):2392.
doi: 10.3390/ma13102392.

The Influences of Moisture on the Mechanical, Morphological and Thermogravimetric Properties of Mineral Wool Made from Basalt Glass Fibers

Andrej Ivanič  1 , Gregor Kravanja  1   2 , Wadie Kidess  1 , Rebeka Rudolf  3 , Samo Lubej  1
Affiliations

The Influences of Moisture on the Mechanical, Morphological and Thermogravimetric Properties of Mineral Wool Made from Basalt Glass Fibers

Andrej Ivanič et al. Materials (Basel). .

Abstract

Mineral wool made from basalt fibers is frequently used as an insulating material in construction systems. In this study, both unused mineral wool and wool obtained from the softened roofing area were comprehensively analyzed in a laboratory using different characterization techniques. Firstly, the initial water content and compressive strength at 10% deformation were determined. Secondly, microstructure and surface chemical composition were analyzed by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX). To study heterogeneities near the fiber surface and to examine cross-sectional composition, a scanning transmission electron microscope (STEM) was used. Finally, to verify possible reasons for resin degradation, thermogravimetric analysis and differential scanning colometry (TGA-DSC) were simultaneously carried out. The results show that natural aging under high humidity and thermal fluctuations greatly affected the surface morphology and chemical composition of the fibrous composite. Phenol-formaldehyde and other hydrophobic compounds that protect fibers against moisture and give compressive resistance were found to be degraded.

Keywords: SEM-EDX; STEM; basalt fibers; compressive strength; degradation; mineral wool; moisture effect; roofing; thermal stability.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Scheme of the roofing structure.
Figure 2
Figure 2
(a) Mineral wool samples taken from softened, uneven roofing areas of a commercial building located in Slovenia, Central Europe. (b) Visual presentation of new and degraded insulation samples.
Figure 3
Figure 3
Moisture content (u) at different relative humidities: comparison between the new and aged samples.
Figure 4
Figure 4
Partial degradation of resin by depolymerization initiated by hydrolysis.
Figure 5
Figure 5
Compressive stress at 10% deformation.
Figure 5
Figure 5
Compressive stress at 10% deformation.
Figure 6
Figure 6
SEM microanalysis of new (a–c) and aged (d–f) insulating material.
Figure 7
Figure 7
SEM-EDX was used to observe the composition of the surface of the new basalt wool sample coated with binder. The thick white uniform layer that surrounds the basalt fiber is the coated binder.
Figure 8
Figure 8
SEM-EDX spectra of the surface of mineral wool fabricated from basalt fibers with two characteristic defects: (a) cracks and (b) bulges.
Figure 9
Figure 9
Scanning transmission electron microscope analysis of fiber surface in nano-scale. Visible formation of a thin ribbed layer on the aged basalt surface (a–c), the parallel cross section of basalt fiber (d), and presence of elements on the surface and in the interior (e).
Figure 10
Figure 10
Results of the TGA-DSC analysis between new and aged samples. Normalized mass change ∆m/mo, where ∆m and mo are the mass change and the initial mass of the sample, respectively.
Figure 11
Figure 11
TGA-DSC analysis in the area below the 400°C. Normalized mass change ∆m/mo, where ∆m and mo are the mass change and the initial mass of the sample, respectively.
See this image and copyright information in PMC

References

    1. D’Alessandro F., Baldinelli G., Bianchi F., Sambuco S., Rufini A. Experimental assessment of the water content influence on thermo-acoustic performance of building insulation materials. Constr. Build. Mater. 2018;158:264–274. doi: 10.1016/j.conbuildmat.2017.10.028. - DOI
    1. Parlato M., Porto S. Organized Framework of Main Possible Applications of Sheep Wool Fibers in Building Components. Sustainability. 2020;12:761. doi: 10.3390/su12030761. - DOI
    1. Yliniemi J., Kinnunen P., Karinkanta P., Illikainen M. Utilization of mineral wools as alkali-activated material precursor. Materials. 2016;9:312. doi: 10.3390/ma9050312. - DOI - PMC - PubMed
    1. Wei B., Cao H., Song S. Tensile behavior contrast of basalt and glass fibers after chemical treatment. Mater. Des. 2010;31:4244–4250. doi: 10.1016/j.matdes.2010.04.009. - DOI
    1. Vrána T., Björk F. Frost formation and condensation in stone–wool insulations. Constr. Build. Mater. 2009;23:1775–1787. doi: 10.1016/j.conbuildmat.2008.10.014. - DOI

LinkOut - more resources