The aim of this paper was to analyze selected properties of beech wood (Fagus sylvatica L.) treated by one-sided surface charring. Specimens were one-side charred with a hot plate using several time-temperature combinations (from 200 to 400 °C). Characteristics such as colour, discoloration, surface roughness, fire resistance, total carbohydrate content at several wood layers and decay resistance were evaluated. Surface charring was applied to the radial and tangential surfaces. Colour measurements showed that the surface of the wood turned grey due to charring. In addition to colour measurements, other experiments showed significant differences between radial and tangential specimens due to their different structures. The higher the temperature used in treating them, the lower the roughness values for radial specimens, while the trend for tangential specimens was the opposite. A smoother surface is more fire resistant, so radial specimens are generally better in this regard. Tangential specimens are more susceptible during preparation to forming cracks that impair flame resistance because a continuous protective densified layer is not formed. The determination of total carbohydrates revealed significant changes at various wood depths after surface charring. These changes were more predictable in radial specimens due to the annual ring orientation, because each layer consisted of a similar earlywood/latewood ratio. Finally, when decay resistance was assessed, weight loss was found to be lower in all specimens than in the references. The results suggest that charring at a particular combination of temperature and time improved the investigated properties of the surface-modified beech.

Three synthetized polymorphs of calcium carbonate have been tested in combination with the suspension of nanolime particles as potential consolidating agents for contrasting stone decay and overcome some of the limitations of nanolime agents when applied to substrates with large porosity. The modifications induced in the pore network of the Maastricht limestone were analyzed with microscopy and in a non-invasive fashion with small angle neutron scattering and synchrotron radiation micro-computed tomography. A reduction in porosity and pore accessibility at the micrometric scale was detected with the latter technique, and ascribed to the improved pore-filling capacity of the consolidation agent containing CaCO₃particles. These were found to be effectively bound to the carbonated nanolime, strengthening the pore-matrix microstructure. Penetration depth and positive effect on porosity were found to depend on the particle size and shape. Absence of significant changes in the fractal nature of the pore surface at the nanoscale, was interpreted as indication of the negligible contribution of nanolime-based materials in the consolidation of stones with large porosity. However, the results indicate that in such cases, their effectiveness may be enhanced when used in combination with CaCO₃particles, owing to the synergic effect of chemical/structural compatibility and particle size distribution.

Nowadays, additive manufacturing—also called 3D printing—represents a well-established technology in the field of the processing of various types of materials manufacturing products used in many industrial sectors. The most common type of 3D printing uses the fused filament fabrication (FFF) method, in which materials based on thermoplastics or elastomers are processed into filaments. Much effort was dedicated to improving the properties and processing of such printed filaments, and various types of inorganic and organic additives have been found to play a beneficial role. One of them, calcium carbonate (CaCO₃), is standardly used as filler for the processing of polymeric materials. However, it is well-known from its different applications that CaCO₃ crystals may represent particles of different morphologies and shapes that may have a crucial impact on the final properties of the resulting products. For this reason, three different synthetic polymorphs of CaCO₃ (aragonite, calcite, and vaterite) and commercially available calcite powders were applied as fillers for the fabrication of polymeric filaments. Analysis of obtained data from different testing techniques has shown significant influence of filament properties depending on the type of applied CaCO₃ polymorph. Aragonite particles showed a beneficial impact on the mechanical properties of produced filaments. The obtained results may help to fabricate products with enhanced properties using 3D printing FFF technology.

One-sided surface charred European beech wood (Fagus sylvatica L.) was studied. Radial and tangential specimens of dimensions of 50 × 25 × 350 mm were one-sided surface charred at 200, 250, 300, 350, and 400 °C for various times using a contact heating system. Specimens of dimensions of 50 × 25 × 50 mm³ were prepared for treatment intensity analysis and its effect on surface wettability. Density profiles of the radial and tangential charred specimens were determined using X-ray densitography with a resolution of 0.05 mm. The wettability of the one-sided surface charred wood specimens was analyzed via contact angle, measured using the sessile drop method and determined over 10 to 150 s. The oven-dried specimens were partially submerged in water and water uptake was recorded after 2, 4, 6, 8, 10, 48, and 72 h according to EN-927-5. The surface density of the radial specimen groups charred at 200 °C for 6 min and 250 °C for 4 min decreased by about 4.5 to 8.2%. With increasingly severe charring, the surface density decreased by about 15.5 to 33.5%. A mild charring process produced a surface charred layer of approx. 2 mm, while higher temperatures and longer times affected the density up to 4–6 mm beneath the surface. Differences were found between the water uptake of the radial and tangential charred beech specimens. The most significant decrease of 56% in water uptake was recorded for the radial group prepared at 200 °C for 20 min after floating in water for 72 h. Water uptake in the radial groups modified at 250 °C for 4 and 6 min after 72 h decreased by 38% and 36%, respectively. The tangential groups did not show any statistically significant decrease. The average water uptake of the groups charred at 200 °C for 20 min, 350 °C for 2 min and 400 °C for 1 min was greater than that of the reference; the variability of the measured data was significantly greater due to the highly anisotropic character of the tangential specimens. Micro cracks were also visible on the surface. Concluding from the results of this study, one-sided surface charred beech wood exhibits increased potential in terms of wood–water related properties when a temperature range of 200–400 °C is applied.