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Construction systems based on cross-laminated timber (CLT) have versatility in material development and are an interesting alternative for construction. This study evaluated the structural performance of cross-laminated timber-bamboo produced from wood (Pinus spp.) and bamboo (Dendrocalamus giganteus). Panels were produced by strips (wood and bamboo) assorted, under non-destructive structural grading, to support a better panel configuration. Small-length pine pieces were also included in the study, considering their low added-value and underutilization in sawmills from Telêmaco Borba, Brazil. Gluing tests of small specimens were performed to evaluate the bonding quality of three adhesives: melamine-urea-formaldehyde (MUF), isocyanate polymeric emulsion (IPE), and castor oil-based resin (COR). Shear stress strength parallel to grain between bamboo and wood showed the best performance for MUF resin. After preliminary gluing testing, eight cross-laminated panels were produced with MUF adhesive in a three-layered configuration, with transversal orientation: two external bamboo layers and a central layer of pine wood. Stiffness and rupture strength values were above those specified by the ANSI/APA PGR 320 (2012) standard. Elasticity and rupture moduli were 13,310 MPa and 65 MPa, respectively, showing good potential of this composite for structural uses.

Las cañas de bambú son un material de construcción único para diversos tipos de estructuras y cada vez hay una mayor aceptación de los bambúes para usos estructurales. Sin embargo, tienen como inconveniente su propensión al ataque por insectos. En este trabajo se hizo un estudio de la eficacia de tres diferentes tipos de preservadores: 1) químicos tradicionales, 2) naturales de bajo riesgo para el ser humano y 3) térmicos a diferentes temperaturas, para prevenir el ataque del insecto escarabajo Dinoderus minutus al bambú de la especie Bambusa vulgaris vittata. Los dos primeros tratamientos se realizaron por inmersión y el tipo térmico fue hecho por el proceso de secado. Cada dos semanas, se evaluó el ataque a tres especímenes de cada tratamiento, incluyendo los correspondientes a un testigo sin elemento preservador alguno. Los resultados mostraron que la mayoría de los tratamientos por inmersión fueron eficaces, reduciendo considerablemente el ataque de los insectos en comparación con el testigo.En cuanto al tratamiento térmico, las temperaturas menores o iguales a 130 °C no mostraron ser eficaces; las temperaturas de 190 °C y 210 °C revelaron eficacias aceptables.

The search for sustainable fuels has become important for the development of energy generation in balance with the environment. Brazil has climatic conditions and a vast territory for the production of forest biomass. The research produced in the laboratory determines the gravimetric yield, upper calorific value, percentages of fixed carbon, volatile and ashes of the charcoals of bamboo species: Bambusa vulgaris var vittatta, Dendrocalamus asper and Phyllostachys pubescens. For the carbonization process, small pieces of bamboo were obtained, were dried in the stove at 100°C for 24 hours, the dried mass was weighed and added in a carbonizer heated to 150°C for 45 minutes, heated to 180°C for 45 minutes and heated to 210°C for 30 minutes, this charcoal was then cooled and weighed to calculate the gravimetric yield. The samples were pulverized in a pot mill, the upper calorific value in a calorimeter was determined. The volatile, fixed carbon and ash contents were determined according to the Brazilian MB-15 method. The results obtained for the species B. vittatta, D. asper and P. pubescens, were respectively: gravimetric yield 44.08%, 42.77% and 47.09%; calorific value 28.806kJ/g, 29.075kJ/g and 28.489kJ/g; percentage of fixed carbon 62.1%, 66.09% and 57.8%; percentage of volatiles 35.89%, 30.92% and 40.4%; ash percentage 2.01%, 2.99% and 1.8%. It was observed that the D. asper specie presented better results in the general context of the analysis carried out because, despite presenting a slightly lower gravimetric yield, it presented the higher calorific value and higher fixed carbons content.

Due to the high dimensional variation of bamboo, the manufacturing of materials such as plywood and laminated bamboo produces a high amount of residues. The production of particleboards could be used to overcome this problem and become a viable solution to reuse the generated waste as a raw material to high value-added products. This study aimed to present an overview of the bamboo particleboard production, as well as the mechanical and physical properties of this material, followed by a review of the advances in its research and development. In general, independently of the resin or bamboo species utilization, several bamboo particleboards meet the mechanical properties requirements of international standards for wood-based medium-density particleboards. The main focus of this study is to provide a review, in order to support research groups interested in using new bamboo-based materials for the development of manufactured durable products. RESUMO Devido à grande variação dimensional do bambu, a produção de materiais como compensados e laminados produz grande quantidade de resíduos. A produção de painéis particulados poderia ser utilizada para superar este problema e tornar-se uma solução viável na reutilização dos resíduos gerados como matéria-prima para produtos de alto valor agregado. Objetivou-se apresentar uma visão geral sobre a produção de painéis particulados de bambu, assim como suas propriedades mecânicas e físicas, acompanhada por uma revisão dos avanços em sua pesquisa e desenvolvimento. Em geral, independentemente da resina ou espécie de bamboo utilizadas, diversos painéis particulados de bambu atendem os requisitos de normas internacionais para painéis particulados de média densidade à base de madeira. O foco principal deste trabalho é fornecer uma revisão para apoiar grupos de pesquisa interessados em utilizar novos materiais à base de bambu para o desenvolvimento de produtos manufaturados duráveis.

The objective of the present work was to study the use of bamboo foils as structural reinforcement for MDP wooden panels. Four wooden panels of homogeneous layer were produced using particles of GT1 and RRIM 600 clones ofHevea brasiliensis(rubber tree), and glued with urea-formaldehyde resin (UF). These panels were also overlaid with foils ofPhyllostachys edulis(mossô bamboo). The tests were realized to evaluate the physical-mechanical characterization according to European standards (EN). The production of the particleboards with reinforcement of bamboo improves the physical-mechanical characteristics of these commercial wooden panels.

The objective of this work was to evaluate the effect of the addition of bamboo laminas of the species Dendrocalamus giganteus to three-layer medium density particleboard (MDP). These laminas were glued onto both the top and the bottom of each panel. With the manufactured panels laminated with bamboo, mechanical tests based on the Brazilian Standard ABNT NBR 14810 were carried out to determine the modulus of rupture (MOR) in static bending and the tensile strength parallel-to-surface. These mechanical tests were realized in particleboards of eucalyptus and in reinforced particleboard, both produced in the laboratory. The modulus of rupture and tensile strength parallel-to-surface of the laminated MDP had values close to those that have been reported. The reinforcements increased the values of these studied properties. Nevertheless, this fact indicated the possibility to produce a stronger MDP using bamboo lamina as surface layers. These results show the possibility of using coated-bamboo MDP for utilization in large spans, for example, in flooring for mezzanines with finish on both sides, and for robust furniture as bookshelves, beds, tables, etc.

Bamboo is a renewable material that has been gaining attention in several sectors of production and research because of its potential. Its special characteristics of rapid growth, short harvest cycle, diversity and excellent mechanical properties. The objective of this work was a physical-mechanical analysis of flooring manufactured by a combination of bamboo (Dendrocalamus giganteus) laminate slats and wood (Pinus taeda) edge-glued panels (EGP). It was based on the ASTM D2394-83/1994 standard, which describes the procedures for mechanical simulation of in-service floors, such as indentation loads applied on small areas, falling ball impact, rolling load, abrasion and friction tests. The results were satisfactory when compared with those of other types of wood. The research showed lignocellulosic composite of Pine EGP with a bamboo surface, in terms of mechanical strength according the ASTM’s standard, is viable and feasible. Therefore, it results that “EGP/Bamboo” composite can be successfully applied for internal floors.

Bamboo-based materials are in the toolbox of sustainable practices and have a high potential for the development and expansion of new products in the construction industry. Although uncountable advantages are attributed to bamboo, there are several problems related to its use that must be solved and mitigated. Without proper treatment, bamboo materials cannot withstand a long service life. The treatment procedures are already well-known, in which different methods and preservative solutions can be used depending on the final application, logistics, material condition, and affordability. Yet, necessary information about the chemical treatment of bamboo in terms of treatability, quality control, and the effect on physical-mechanical properties, and the development of less hazardous solutions are topics not adequately explored. Therefore, this doctorate thesis was divided into two major parts/objectives: assessment of conventional bamboo treatments and evaluation of alternative preservation methods based on chemical modification and in-situ polymerization. In the first part, conventional preservatives were applied for Dendrocalamus. asper and Phyllostachys edulis bamboo treatment and analysed in the quality aspects point of view. Analytical methods for treatability evaluation, such as penetration and retention, were used for disodium octaborate tetrahydrate (DOT) and chromate copper borate (CCB) treated bamboo. Mechanical, physical, and chemical tests were extensively used to characterize treated samples, and the effects of the preservatives on mechanical properties were investigated. Additionally, full-culm bamboo was object of detailed mechanical characterization through digital image correlation strain analysis. The obtained results led in recommendations for future standards for bamboo testing and the observation of the local effect of the node on compression, shear, tension, and bending. Besides, the investigated treatments did not show detrimental effects on the mechanical properties, yet DOT treatment causes an improvement in bamboo strength. Guidelines for treatment by the immersion method using DOT are also proposed to ensure the production quality of treated bamboo. In the second part of this thesis, pursuing the objective to improve the overall properties of bamboo, alternative treatment formulations based on citric acid and tannin in combination with boron compounds were tested. Samples chemically modified with citric acid presented considerable improvement on dimensional stability and decrease of water absorption as the consequence of an esterification process. However, the modification increased bamboo brittleness, reducing especially tension and bending strengths. The use of polymerized tannin/hexamine/boron had positive outcomes on the overall properties of bamboo, increasing the compression and bending strengths and the fungi degradation resistance even after leaching. Moreover, although DOT was effective in improving fungi decay resistance, severe leaching completely decreased its fungicide activity. Through thermogravimetric analyses, boron treated samples exhibited better thermal stability. In general, bamboo is a fascinating material. Nevertheless, although satisfactory treatment can be achieved, it is more difficult to be treated and characterised than wood. To overcome these problems, more research in characterization and treatment methods are necessary for better understanding and use of this abundant and versatile material. Os materiais à base de bambu estão na caixa de ferramentas de práticas sustentáveis e têm um alto potencial para o desenvolvimento e a expansão de novos produtos na indústria da construção. Embora inúmeras vantagens sejam atribuídas ao bambu, existem vários problemas relacionados ao seu uso que devem ser resolvidos e mitigados. Sem tratamento adequado, os materiais de bambu não resistem a uma longa vida útil. Os procedimentos de tratamento são bem conhecidos, para os quais diversos métodos e soluções preservativas podem ser utilizados, dependendo da aplicação final, logística, condição do material e acessibilidade. No entanto, informações básicas sobre o tratamento químico do bambu em termos de tratabilidade, controle de qualidade e o efeito nas propriedades físico-mecânicas e o desenvolvimento de soluções menos perigosas são tópicos pouco explorados. Portanto, esta tese de doutorado foi dividida em duas partes/objetivos principais: avaliação de tratamentos convencionais para bambu e o uso de métodos de preservação alternativos baseados em modificação química e polimerização in-situ. Na primeira parte, preservativos convencionais foram aplicados no tratamento dos bambus Dendrocalamus. asper e Phyllostachys edulis e analisados sob o ponto de vista de aspectos de qualidade. Métodos analíticos para avaliação da tratabilidade, como penetração e retenção, foram utilizados para o bambu tratado com octaborato de sódio tetrahidratado (OST) e cromato de cobre cromatado (CCB). Testes mecânicos, físicos e químicos foram amplamente utilizados para caracterizar amostras tratadas e os efeitos dos preservativos nas propriedades mecânicas foram investigados. Adicionalmente, o bambu roliço foi objeto de caracterização mecânica detalhada por meio de análise de deformação por correlação de imagem digital. Os resultados obtidos resultaram em recomendações para futuras normas para ensaios de bambu e na observação do efeito local do nó em compressão, cisalhamento, tração e flexão. Ademais, os tratamentos investigados não mostraram efeitos prejudiciais sobre as propriedades mecânicas, especialmente o tratamento com OST, que resulta em uma melhora na resistência do bambu. Diretrizes para tratamento pelo método de imersão usando OST também foram apresentadas como uma proposta para melhorar a qualidade da produção do bambu tratado. Na segunda parte desta tese, seguindo o objetivo de melhorar as propriedades gerais do bambu, foram testados tratamentos alternativos à base de ácido cítrico e tanino em combinação com compostos de boro. Amostras quimicamente modificadas com ácido cítrico apresentaram considerável melhora na estabilidade dimensional e diminuição da absorção de água como consequência de um processo de esterificação. No entanto, a modificação aumentou a fragilidade do bambu, reduzindo especialmente a resistência à flexão. O uso de tanino/hexamina/boro polimerizado apresentou resultados positivos nas propriedades gerais do bambu, aumentando as resistências à compressão e à tração na flexão e a resistência à degradação por fungos mesmo após a lixiviação. Embora o OST tenha sido eficaz para melhorar a resistência à decomposição de fungos, a lixiviação severa diminuiu completamente sua atividade fungicida. Contudo, por meio de análises termogravimétricas, as amostras tratadas com boro exibiram melhor estabilidade térmica. Em geral, o bambu é um material fascinante. No entanto, embora seja possível obter um tratamento satisfatório, é mais difícil de ser tratado e caracterizado do que a madeira. Para superar esses problemas, são necessárias mais pesquisas em métodos de caracterização e tratamento para melhor entendimento e uso desse abundante e versátil material.