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Eucalyptus urophylla (ampupu) is one of the most commonly cultivated species in Brazil for industrial scale particleboard production. This study investigates the reuse of Eucalyptus urophylla sawmill waste as a raw material for particleboard manufacturing, addressing the growing need for sustainable material solutions. Without prior particle homogenization, two manufacturing approaches were tested: single-layer and three-layer boards. Using a castor-oil-based polyurethane resin (10 % for single-layer and 12 % for three-layer boards), the panels were pressed at 5 MPa for 10 minutes at 100 °C. Performance evaluation under standards revealed that multilayer panels demonstrated superior mechanical and physical properties, while single-layer boards did not meet classification standards, highlighting the benefits of optimizing wood waste in multilayer compositions.

Particleboards find extensive application in both civil construction and the furniture industry. Nevertheless, concerns about the interaction of panels with humidity require the exploration of alternative sources to develop a product that meets the requirements for use. This work aims to produce single-layer particleboards with coconut fiber (Cocos nucifera) as substrate, bonded with 10% by mass castor oil-based polyurethane resin (CPUR). Two groups of mixtures were proposed, different from each other in the initial moisture content of the Cocos nucifera particles, ranging from 0 to 2% and from 4% to 6%. For this purpose, density (D), thickness swelling after 24 h (TS), moisture content (MC), and water absorption (WA) were evaluated. The Tukey mean contrast test, at a 5% significance level, was used to verify the influence of the initial moisture content of the particles on the physical properties of the particleboards. The microstructure of the composites was assessed through the utilization of scanning electron microscopy (SEM) technique. The results indicated better compaction of the C. nucifera particles, resulting in fewer voids, contributing to the densification of the panels and, with this, the reduction of water absorption by 15.1%.

To reduce dependence on wood and deforestation, alternative materials have been considered. This research evaluated particleboards panels of Pinus elliotti mixed with residues of polyethylene terephthalate (PET) in flakes with 50% of each material, glued with 10% of castor oil-based polyurethane resin (PUR). The temperature during board production was varied to evaluate its influence on the physical and mechanical properties of the boards. The study concludes that the increase in temperature did not result in a significant improvement in the particleboard properties, but their results showed application potential according to the normative standards.

Atualmente a utilização de madeiras de florestas plantadas para fabricação de derivados vem crescendo, sendo as espécies Hevea brasiliensis e Tectona grandis alternativas devido à abrangência de seus reflorestamentos no Brasil. Considerando seus ciclos de produção em torno de 30 anos, essas espécies podem ser alternativas de matéria-prima para fabricação de derivados de madeira. O objetivo desse trabalho foi produzir painéis aglomerados utilizando as referidas espécies, aglutinando-as com adesivo poliuretano derivado do óleo de mamona. Os painéis foram avaliados de acordo com suas propriedades físico-mecânicas, com base na ABNT NBR 14810 - 1 e 2 e demais literaturas nacionais e internacionais. Foram considerados dois tratamentos empregando-se 10% e 5% de adesivo, ambos com mistura de 30% de seringueira e 70% de teca. Para cada tratamento foram produzidos três painéis e avaliados suas densidades, teor de umidade, inchamento em espessura, módulo de resistência à flexão estática, módulo de elasticidade e resistência à tração perpendicular. Os resultados obtidos evidenciaram potencialidades de uso das duas espécies de madeira para a produção de painéis aglomerados. Os painéis produzidos com 10% de adesivo apresentaram melhores resultados em comparação aos painéis com 5%, entretanto, o emprego de 5% de adesivo atende às exigências normativas brasileiras.

Abstract The society’s development provides consequences such as the increasing generation of industrial waste. In the city of Franca, São Paulo’s inland city, there are footwear industries that generate a large amount of leather waste during their production process. In most cases, there’s no use of this waste and they’re disposed of in landfills. A reuse alternative is the production of particleboards used in construction sectors. Therefore, one of the biggest challenges is the use of this leather waste adding value to the product and enabling the production of sustainable material. This work proposes the production of particleboards from Eucalyptus wood and leather fibers using castor oil polyurethane adhesive. In addition, the assessment of the leather fiber influence on modulus of rupture and elasticity obtained from a static bending test. The study investigated the proportion of 10%, 25% e 50% leather waste in relation to Eucalyptus particles and 10% castor oil polyurethane adhesive. The mechanical performance of the panels was evaluated based on ABNT NBR 14810-1 and 2 (2013; 2018). The results allowed us to ascertain that the incorporation of 10% leather waste in particleboard rated them, according to NBR 14810-1 and 2 (2013; 2018), as structural panels of type P4 for use in dry conditions.

Abstract This work describes proposed experimental methods for the characterization of concrete in fresh and hardened state, with the purpose of contributing to the experimental characterization of concrete. The main objective was to identify the rheological behavior of high performance (HP) and self-compacting (SC) concretes. Initially, a ordinary concrete composition was proposed, from which, silica fume (5, 10 and 15% in mass) and superplasticizer (0.6% in mass) were added to obtain HPC and SCC. Furthermore, for the self-compacting concretes, a modification in granular skeleton was proposed, with a reduction of total aggregate percentage by 22.73% in relation to the other compositions. The interference of these modifications was evaluated on the behavior of fresh concrete though the flow and slump test and hardened concrete through mechanical properties. The results showed that the modification in the granular skeleton of ordinary concrete contributed directly to the reduction of inertia factors of SCC, favoring the mobility conditions. For both self-compacting and high performance concretes, consistency and mechanical strength gain over ordinary concrete were influenced when the silica fume and superplasticizer concentration was increased, limiting your properties gains to these additions.