In this study, dynamic hardness tests on solid and engineered wood flooring specimens of Eucalyptus globulus Labill. and Eucalyptus grandis W. Hill ex Maiden hardwoods were performed because nowadays, these fast-growing hardwoods are still scarcely employed for this use. Furthermore, another two examples of hardwood commonly applied on wood flooring, Quercus robur L. and Hymenaea courbaril L., were also tested. To compare their properties, a dynamic impact hardness test based on the impact of steel balls, with several diameters, and drop heights was developed. Accordingly, 120 solid wood flooring specimens and 120 engineering wood flooring specimens were producing with these four hardwood species. Dynamic impact tests were made with three steel balls of different diameters (30–40–50 mm), and they were carried out from five different drop heights (0.60–0.75–0.90–1.05–1.20 m). The impact of the steel ball drew the size of the footprint on the surface and this mark was measured with a digital caliper for both dimensions, diameter and depth, as footprint diameter (FD) and indentation depth (ID). Data from 3000 samples, corresponding to 120 different individual groups (4 species × 3 ball diameters × 5 drop height × 2 floor type) were analyzed. Results indicated that the variability of ID (CV between 19.25–25.61%) is much greater than the values achieved for FD (CV between 6.72–7.91%). Regarding the fast-growing hardwood species tested, E. globulus showed a similar behavior to traditional hardwood applied on wood flooring in Europe, Q. robur, and it could be a promising growth in the flooring industry. However, E. grandis showed the worst values compared to traditional hardwood in all test configurations.

This study focuses on Populus ×euramericana (Dode) Guinier, a globally distributed fast-growing tree. Despite its valuable wood, it exhibits low durability. The aim of this study was to assess the efficacy of a binary composite comprising silver nanoparticles (AgNPs) and chitosan oligomers (COS) in protecting P. ×euramericana ‘I-214’ wood against degradation caused by xylophagous fungi and termites through vacuum-pressure impregnation. The test material was carefully selected and conditioned following the guidelines of EN 350:2016, and impregnation was carried out in accordance with EN 113-1:2021. Five concentrations of AgNPs–COS composites were utilized. Biodeterioration resistance was evaluated based on EN 350:2016 for white (Trametes versicolor (L.) Lloyd) and brown (Coniophora puteana (Schumach.) P.Karst.) rot fungi, and EN 117:2012 for subterranean termites (Reticulitermis grassei Clément). The durability class and use class were assigned following EN 350:2016 and EN 335:2013, respectively. In comparison to the untreated control, the binary solution at its highest concentration (AgNPs 4 ppm + COS 20 g·L⁻¹) demonstrated a notable reduction in weight loss, decreasing from 41.96 ± 4.49% to 30.15 ± 3.08% for white-rot fungi and from 41.93 ± 4.33% to 27.22 ± 0.66% for brown rot fungi. Furthermore, the observed termite infestation shifted from “heavy” to “attempted attack”, resulting in a decrease in the survival rate from 53.98 ± 10.40% to 26.62 ± 8.63%. Consequently, the durability classification of P. ×euramericana I-214 witnessed an enhancement from “Not durable” to “Slightly” and “Moderately durable” concerning decay fungi and termites, respectively. These findings expand the potential applications of this wood and substantiate the advantages of employing this environmentally friendly treatment.

Aim of study: To evaluate the effect of heat treatment (HT) on hardness, density and color of Populus × canadensis ´I-214´ (poplar) wood. Area of study: 15-years-old poplar wood from Pomona, Río Negro, Argentina. Material and methods: 352 samples were exposed to different HT schedules: 120ºC, 160ºC, 180ºC and 200°C for 45 min, 90 min, 135 min and 180 min. Hardness, density and color were determined before and after each HT combination. Hardness and density tests were performed following the specifications of IRAM standards and wood color was determined according to CIELab system. Main results: Hardness improved significantly at 160°C for 45 min and 90 min in comparison with control (14.34% and 9.08%, respectively) whereas this property was improved at 120°C in all cases without significant differences. The 200°C: 45 min schedule showed the worst performance with a 20.26% hardness loss. Density was lower than the control in all schedules with losses ranging from 2.50% to 10.00%. Color became darker (decrease in L value, increase in a and b values) as HT intensity increased (mainly temperature), with changes becoming evident at 180°C and 200°C. Research highlights: HT on P. × canadensis ‘I-214’ improved its hardness under two HT schedules, although was not enough to extend the feasible applications, since it still belongs to a category of “soft” wood. Hardness and density did not show a clear correlation and color of poplar wood became darker as HT intensity increased.

Hardness is a key mechanical property of flooring materials. In this study, the performance of veneer floorings (with a top layer thickness of 0.6 mm) was investigated by dynamic hardness tests, comparing it with those of traditional engineered wood floorings (with a top layer thickness of 3 mm) and solid wood floorings. Two hardwoods commonly used on wood flooring, viz. Quercus robur L. and Hymenaea courbaril L., and two fast-growing hardwoods, Eucalyptus globulus Labill. and Eucalyptus grandis W. Hill ex Maiden, were tested as top layers. To compare their usage properties, a dynamic impact hardness test involving steel balls with three diameters and five different drop heights was carried out, measuring the footprint diameter (FD) and the indentation depth (ID). The data from 4800 impacts, corresponding to 180 different individual groups (4 hardwood species × 3 ball diameters × 5 drop heights × 3 floor types) were analyzed. The results showed that the general response in terms of both FD and ID was better in the engineered wood floorings than in solid wood floorings, and that the veneer floorings (0.6 mm) showed better behavior than traditional engineered wood floorings (3.0 mm). Furthermore, for the veneer floorings, the two fast-growing hardwood species tested, which have significantly different densities, showed similar behavior to traditional hardwoods, suggesting that they would be suitable for valorization in the wood flooring industry.

Aim of study: to assess the natural durability of Populus x euramericana ‘I-214’ against xylophagous fungi and termites, and to carry out a macro-microscopic analysis of the alterations caused by each xylophagous agent in order to get the necessary information for its possible inclusion in existing European standards.Area of study: A 20-years-old commercial plantation Populus x euramericana‘I-214’ located in Quintanilla de Sollamas (42° 36′ 00″N - 05° 49′ 00″ W), Spanish community of Castile-LeonMaterial and methods: material sampling and selection was carried out following EN 350:2017 for commercial sawn timber. Poplar resistance to xylophagous basidiomycete, soft rot fungi and subterranean termites was determined according to CEN/TS 15083-1:2005, CEN/TS 15083-2:2005 and EN 117:2012, respectively. The durability and use classes were estimated according to EN 350:2016 and EN 335:2013, respectively. The anatomical studies were carried out with Optical and Scanning Electron Microscope. Material characterization was carried out by reference to Anagnost (1998) and Schwarze (2007).Main results: ‘I-214’ poplar wood proved to be “Not-durable” to the action of basidiomycetes, soft rot fungi and termites, use classes 1-2, and showed macro-microscopic evidence of these types of decay.Research highlights: the information obtained in this study would allow the inclusion of clone I-214 in the standard EN 350 and its explicit classification within it.Keywords: wood-decay fungi; termites; EN 350.Abbreviations used: TM: test material; RM: reference material; RH: relative humidity; ML: mass loss; mi: initial dry mass; mf: final dry mass; DC: durability class; OM: Optical Microscope; SEM: Scanning Electron Microscope; TS: transverse section samples; LS: longitudinal section samples; CI: robust confidence intervals; F: fibre; V: vessel; h: hole; t: erosion trough; R: radial parenchyma cell; ep: erosion pitting; Fc: fungal colonization; fr: fracture; c: cavity; b: bore hole; m: mycelium.