This study investigates the mechanical and physical properties of a wood-based polymer composite DuraSense® 3D S50 Flex K to enhance its potential in large-scale additive manufacturing by studying the influence of printing orientation on the mechanical characteristics of the product. To assess performance, the specimens were produced with different printing layer orientations: at 0°, 30°, 45°, and 90° to the sample length, which corresponds to load application during the tests. Tensile strength, flexural strength, modulus of elasticity, hardness, water absorption, thermophysical properties and microstructure were determined for the samples. The 0° specimens exhibited the highest tensile (15.39 MPa) and flexural strength (26.05 MPa), while the 90° orientation specimens showed reductions in strength of 72% and 69%, respectively. The modulus of elasticity also decreased by 71% at 90°, confirming anisotropy. Additional tests revealed a Brinell hardness of 179.9 N/mm ² , a water absorption of 19.75%, with minimal dimensional change, and a thermal conductivity of 0.1553 W/m·K. Microscopic analysis showed porosity and uneven fibre distribution, indicating the need for composite optimisation. These findings confirm the importance of orientation-aware design in large-scale additive manufacturing and provide the background for future work focusing on the development of printing strategies and computational modelling to enhance print quality, interlayer adhesion, and performance in applications.

In this study, the characteristics of concretes made from mixed recycled aggregate—the cheapest and most common secondary raw material in construction and demolition waste—were determined. For this study, besides experimental concretes using mixed recycled aggregate, reference compositions were developed using river gravel, recycled concrete aggregate, and recycled masonry aggregate. The workability of concrete mixtures was measured as class S1, which is acceptable for use with slipform concrete pavers, and was achieved by varying the water/cement ratio, considering the different water adsorptions of the concrete fillers. The following mechanical characteristics of the concretes were defined on the 3rd and 28th days: density, compressive strength, flexural strength, water absorption, and frost resistance. The test results showed sufficiently high indicators of strength and durability for the recycled aggregate concretes. Moreover, the strength of the concrete developed from mixed recycled aggregate was comparable with that of the reference concretes. Considering the low strength requirements for the construction of the lower layers of rigid pavements, it was established that such an application of recycled aggregate concrete, including that derived from mixed recycled aggregate, could be permitted.

This research investigates large-scale additive manufacturing of functional components from wood–based polymer composite on polylactic acid, containing 20 wt% cellulose fibres derived from birch. The main physico-mechanical characteristics of the printed specimens were evaluated, including tensile strength, flexural strength, hardness, density, water absorption, deformation, and thermophysical properties, as well as the microstructure using optical and scanning electron microscopy. The study investigates printing orientation-dependent anisotropy, which remains insufficiently characterised for PLA-based wood composites produced by LSAM. The influence of printing strategy was assessed by varying the printing layer orientation at 0°, 30°, 45°, 60° and 90° relative to the loading direction. The results show a strong dependence of mechanical properties on layer alignment: tensile strength decreased from 18.61 MPa (0°) to 5.22 MPa (90°), and flexural strength from 23.98 MPa (0°) to 6.87 MPa (90°), corresponding to reductions of approximately 70–72%. Scanning electron microscopy linked this anisotropy to weak interlayer adhesion and elevated porosity relative to the feedstock granules, supporting the interlayer interface as a dominant factor governing off-axis strength. The results confirm that the studied composite provides sufficient strength and durability for applications in furniture, design elements, tools, and building structures fabricated by large-scale additive manufacturing.

A series of concretes on recycled aggregates for the construction of lower layers of rigid pavements have been developed, that incorporate micro- and macro- polypropylene fibre and glass fibre. Fibre was added to three base compositions containing different aggregates, i.e. river gravel, quartz sand and coarse and fine size recycled concrete aggregate. All the mixtures used a cement with a high slag content at a dosage of 300 kg/m ³ and were designed for an S1 consistency. The inclusion of fibre significantly affected the fresh concrete's water demand, which demonstrated an increase in the w/c by 7 – 15 %. Mechanical testing on the 28th day showed that neither polypropylene fibre improved the compressive strength and even caused a slight reduction (0.3 – 5 %), which was a result primarily attributed to the associated increase in the w/c ratio. The macrofibre also reduced the flexural strength by 5 – 6 %; the microfibre provided only a marginal increase in the flexural strength (1 – 4 %). In contrast, the alkali-resistant glass fibre was the only type to enhance both the compressive and flexural strength, increasing them by 4 – 12 % and 9 %, respectively. All the fibre-reinforced mixtures achieved a frost resistance grade of at least F100. The research concluded that for stiff mixtures made with recycled aggregates, the tested polypropylene fibres are inefficient, whereas the alkali-resistant glass fibre presents a viable option for performance enhancement.