Microbiological Stability of Bio-Based Building Materials

Abstract

The aim of this paper was to study the microbiological stability of bio-based composite building materials, which are made using organic-rich lake sediments (further -sapropel) with lime and magnesium cement as binders and hemp shives as filler. The microbial stability properties of the obtained composite materials were investigated and compared to similar composites. Because of their high organic content, these materials are prone to biodegradation; therefore, they were coated with ALINA LIFE TM organoclay coating, which helps to extend the product life, reducing the rate of biodegradation compared to the biocides used in industry. The effect of the coating on the resistance to decay by the Aspergillus versicolor, Penicillium chrysogenum, Alternaria alternata, Cladosporium herbarum, Chaetomium sp. and Trichoderma asperellum fungi was investigated under different conditions: relative humidity modes of 75% and 99% at 20°C for 45 days and four months. The results indicated that the composites made of sapropel and lime have similar microbial stability properties as lime and magnesium cement binder composite materials. ALINA LIFE TM organoclay coating showed advanced resistance to biodegradation; sapropel-lime composites have shown several good properties that make them suitable to be considered for use in the construction material industry.

Properties of Sound Absorption Composite Materials Developed Using Flax Fiber, Sphagnum Moss, Vermiculite, and Sapropel

“…The created material samples A1 and A2, 22.7 mm and 23.3 mm thick, were compared with the previously studied [ 21 ] materials MOC1, MOC2, MOC3, FHL, and MPC. The thickest materials were compared because they corresponded more closely to the dimensions of the hemp composite materials.…”

“…The created materials without fungal inoculation K (control) were also kept in the climate chambers. The previously studied [ 21 ] composite materials MOC1, MOC2, and MOC3 were also incubated for comparison ( Table 2 ).…”

“…For MOC materials, the fungal spread was not observed visually. The pH of the hemp clumps, magnesium oxychloride materials, was much higher (9.76) [ 21 ] than the developed sapropel-filler materials, as seen in Figure 8 .…”

“…The composition and designations of the created materials are described in Table 2. The obtained results of sound absorption and microbiological durability tests were compared with 5 previously studied [21] environmentally friendly composite materials. The composition and designations of which are described in Table 3.…”

“…The resulting composites without additives had a sound absorption in lower frequencies and a high absorption in higher frequencies (Figure 6). The created material samples A1 and A2, 22.7 mm and 23.3 mm thick, were compared with the previously studied [21] materials MOC1, MOC2, MOC3, FHL, and MPC. The thickest materials were compared because they corresponded more closely to the dimensions of the hemp composite materials.…”