ABSTRACT Housing deficit is a problem that affects low-income populations in Brazil, with over 6 million families affected nationwide and approximately 631 thousand in the North region of the country. Ordinance no. 318/2014 of the Brazilian Ministry of Cities authorized the construction of popular housing using timber as raw material in that region. The objective of this study was to establish the unit cost of a wooden dwelling, referenced in the project Popular Wooden Housing (PWH) developed by the Laboratory of Forest Products and the University of Brasília (UNB) for the National Rural Housing Program (NRHP). The Basic Unit Cost (BUC/m2 ) methodology was used, with collection of prices in Rio Branco, capital of the state of Acre, for composition of the Final Unit Cost (FCU/m2) of a wood construction. Mean cost of R$ 934.52/m2 was observed from September 2015 to April 2016. Feasibility of wood construction was demonstrated by a final cost per m2 28.06% lower than that of a conventional masonry house.

Abstract: This study was conducted in cooperation with a United States pulp and paper company targeting part of the pulp production as raw material for fiber-reinforced cement sheets manufacturing. Virgin kraft pulp of Douglas fir (Pseudotsuga menziesii) and recycled fiber of old corrugated containers were used in making wood fiber-cement flat sheets. The physical and mechanical properties of the sheets were compared with an available commercial product. Results showed that Douglas fir fiber is a potential choice as reinforcement for wood fiber-cement sheets, as this fiber type outperformed the commercial ones for most of the properties studied. The difference in kappa number from 25 to 35 did not have any effect on the properties of Douglas fir sheets. Even recycled old corrugated containers fiber provided sheets with some properties comparable to the commercial product. Scanning electron microscopy analysis showed that a dual mechanism of fiber breakage and pull out occurred at rupture.

RESUMO Painéis foram produzidos com taliscas de bambu (Guadua magna) montados em três ou cinco camadas cruzadas entre si em ângulo de 90° e coladas com resina à base de fenol-formaldeído ou PVA. Os painéis foram testados e as propriedades físicas e mecânicas determinadas. Os testes foram quanto aos adesivos comerciais usados, bem como a quantidade de camadas dos painéis. A densidade variou entre 0,690 e 0,768 g.cm-3. Painéis colados com resina PVA mostraram baixa resistência mecânica, apresentando MOR entre 6,7 e 7,8 MPa. Os colados com resina fenol-formaldeído foram mais resistentes, com módulo de ruptura (MOR) entre 55,5 e 87,0 MPa, excelente para painéis similares à base de madeira. Painéis com resina fenólica apresentaram também reduzido inchamento em espessura, até 8,4%. Os painéis produzidos em três camadas apresentaram resistência maior à flexão que os com cinco camadas.

ABSTRACT Panels were produced with strips of bamboo (Guadua magna) in layers crossed at angles of 90° and bonded with phenol-formaldehyde or PVA based resin, glued in three and five plies. The panels were tested and the physical and mechanical properties determined. The tests were primarily related to the commercial adhesives used as well as the number of layers of bamboo used. The density ranged from 0.690 to 0.768 g.cm-3. Panels bonded with PVA resin showed low mechanical strength, with MOR between 6.7 and 7.8 MPa. Those bonded with phenol-formaldehyde adhesive showed high strength, with modulus of rupture (MOR) ranging from 55.5 to 87.0 MPa, which is excellent for boards similar to wood-based panels. Panels with phenolic resin also had reduced thickness swelling, up to 8.4%. The panels made with three layers showed higher resistance to bending than those made with five layers.

RESUMO Os objetivos deste estudo foram: avaliar a durabilidade natural de três espécies de tauari (Couratari guianensis Aublet, Couratari oblongifolia Ducke & Knuth R. e Couratari stellata A.C.Smith), relatar os parâmetros colorimétricos de acordo com o sistema CIE L * a * b * 1976 assim como mostrar a aparência dos blocos de madeira antes e após o ataque. Dois fungos de podridão-parda [Gloeophyllum trabeum (Persoon ex Fries) Murril. e Lentinus lepideus Fr.] e dois de podridão-branca [Trametes versicolor (Linnaeus ex Fries) Pilat e Ganoderma applanatum (Pers. ex Wallr.)] foram utilizados. A madeira de tauari foi classificada como "moderadamente resistente" a "resistente" quando exposta aos fungos Gloeophyllum trabeum, Trametes versicolor e Ganoderma applanatum. O conteúdo de extrativos das amostras atacadas diminuiu quando comparado com o controle, exceto Couratari stellata expostos a Ganoderma applanatum. Por outro lado, os conteúdos de cinzas aumentaram quando comparados com o controle, exceto para a madeira de Couratari stellata exposto ao Gloeophyllum trabeum. Todos os blocos de madeira atacados e as serragens tornaram-se mais escuras, exceto para a serragem de Couratari stellata exposto ao fungoTrametes versicolor, e mais vermelho do que a amostra sem ataque. O ΔE * médio do bloco de madeira e serragem, atacados, atingiram 29,5 e 14,3, respectivamente.

ABSTRACT The purposes of this study were to: evaluate de natural durability of three species of tauari (Couratari guianensis Aublet, Couratari oblongifolia Ducke & R.Knuth and Couratari stellata A.C.Smith), report the colorimetric parameters according to CIE L*a*b* 1976 system and also show the appearance of control and attacked wood blocks. Two brown-rot [Gloeophyllum trabeum (Persoon ex Fries) Murril. and Lentinus lepideus Fr.] and two white-rot [Trametes versicolor (Linnaeus ex Fries) Pilat and Ganoderma applanatum (Pers. ex Wallr.)] fungi were used.Tauari wood was classed as "moderately resistant" to "resistant" when exposed toGloeophyllum trabeum, Trametes versicolor andGanoderma applanatum fungi. All extractives' contents of attacked samples decreased when compared with the control (sound wood), exceptCouratari stellata exposed to Ganoderma applanatum.Conversely, all ash contents increased when compared with the control, except Couratari stellata exposed to Gloeophyllum trabeum. All attacked wood blocks and wood meal samples were darker, except wood meal from Couratari stellata exposed toTrametes versicolor, and redder than the control. The∆E* mean value in attacked wood blocks and wood meal samples attained 29.5 and 14.3, respectively.

RESUMO O objetivo do trabalho foi avaliar a resistência natural de chapas de partículas orientadas (OSB) confeccionadas com partículas de Hevea brasiliensis Müll.Arg. aderidas com as resinas sintéticas uréia- formaldeído (UF) e fenol-formaldeído (FF), a 5% e 8%, expostas a fungos xilófagos em condições de laboratório. No ensaio acelerado de laboratório as amostras foram submetidas ao ataque dos fungos de podridão-parda Gloeophyllum trabeum (Pers. : Fr.) Murril, Coniophora puteana (Schumach. : Fr.) P. Karst., Meruliporia incrassata (Berk. & M.A. Curtis) Murrill e também aos fungos de podridão-branca, Fomes annosus (Fr. : Fr.) Cooke, Trametes versicolor (L. : Fr.) Pilát, Ganoderma applanatum (Pers.) Pat., Bjerkandera fumosa (Pers. : Fr.) P. Karst. e Phanerochaete chrysosporium Burds. Dentre os fungos de podridão-parda, o Gloeophyllum trabeum causou a maior perda de massa nos corpos-de-prova testados. Dentre os fungos de podridão-branca, Trametes versicolor, Phanerochaete chrysosporium e Ganoderma applanatum causaram as maiores perdas de massa, sem diferença significativa para o Gloeophyllum trabeum. A resina FF proporcionou maior resistência à ação dos fungos nas chapas OSB, o mesmo fato ocorrendo com o maior teor de resina. O fungo Coniophora puteana foi altamente sensível ao tipo de resina aplicado, enquanto o Bjerkandera fumosa demonstrou reduzida ação nas concentrações mais altas de ambas as resinas. O fungo Fomes annosus apresentou degradação insignificante para todos os tratamentos de chapas OSB.

ABSTRACT This work aimed to evaluate the natural durability of oriented strandboards (OSB) manufactured with strands of Hevea brasiliensis Müll.Arg. bonded with 5% and 8% of urea-formaldehyde (UF) and phenol-formadehyde (FF) resins, exposed to xilophagous fungi under laboratory conditions. In accelerated laboratory test decay, samples of OSB were exposed to the following fungi: the brown-rot fungi Gloeophyllum trabeum (Pers. ex Fries) Murr., Coniophora puteana (Schumach. : Fr.)P. Karst., Meruliporia incrassata (Berk. & M.A. Curtis) Murrill as well as the white-rot fungi Fomes annosus (Fr. : Fr.) Cooke, Trametes versicolor (L. : Fr.) Pilát, Ganoderma applanatum (Pers.) Pat., Bjerkandera fumosa (Pers. : Fr.) P. Karst. and Phanerochaete chrysosporium Burds. Among the brown-rot fungi, the Gloeophyllum trabeum was the most aggressive, showing the highest loss of mass. Trametes versicolor and Ganoderma applanatum confirmed the preference for broadleave species. All oriented strandboards at lower UF resin contents were more degraded by Phanerochaete chrysosporium, Trametes versicolor, Ganoderma applanatum, Merulia incrassata, Coniophora puteana and Gloeophyllum trabeum, with high rate of loss of mass. Coniophora puteana showed small loss of mass when FF resin was applied. Bjerkandera fumosa showed low loss of mass only at higher resin content. Oriented strandboards exposed to Coniophora puteana showed insignificant OSB degradation.

RESUMO O objetivo deste trabalho foi avaliar o efeito da adição de microssílica em três porcentagens (0, 20 e 30%) sobre as propriedades físicas e mecânicas de painéis cimento-madeira de Eucalyptus urophylla compostos por três relações madeira:casca (100:0, 95:5 e 90:10). Os resultados mostraram que o efeito mais significativo do aditivo sobre os painéis produzidos ocorreu naqueles que continham casca, e que a adição de 20% do aditivo foi mais eficiente sobre as propriedades físicas e mecânicas.

ABSTRACT This work’s objective was to evaluate the effect of three percentages of addition of microsilica (0, 20 and 30%) on the physical and mechanical properties of wood-cement bonded particleboards of Eucalyptus urophylla composed by three wood:bark ratios (100:0, 95:5 and 90:10). Results showed that the most significant effect of the additive on the produced panels was in those containing bark, and that of 20% of additive was more efficient on the physical and mechanical properties.

Abstract The decay resistance of wood-plastic composites composed of chips of Eucalyptus grandis W. Hill ex Maiden and low density polyethylene (LDPE) was evaluated according to ASTM D 2017-81 (1994). The samples with plastic wood ratios of 40/60, 50/50, 60/40 e 100/0 were exposed to laboratory decay test using white-rot Trametes versicolor (Linnaeus ex Fries) Pilát and brown-rot Gloeophyllum trabeum (Persoon ex Fries) Murrill fungi. All composites were graded as “highly resistant” to the fungi attack, except the one made with 40% of plastic and exposed to the brown-rot fungus, which was graded as “resistant”. The decay susceptibility index (DSI) was calculated as well and showed that the composites were more resistant to fungi attack than the wood used as reference.

Resumo A resistência à degradação de chapas de madeira-plástico aos fungos de podridão-branca, Trametes versicolor (Linnaeus ex Fries) Pilát, e de podridão-parda, Gloeophyllum trabeum (Persoon ex Fries) Murrill, foi avaliada conforme a norma ASTM D 2017-81 (1994). As chapas foram confeccionadas com cavacos de Eucalyptus grandis e pellets de polietileno de baixa densidade (PEBD) pós-consumo nas proporções de plástico/madeira de 40/60, 50/50, 60/40 e 100/0. Utilizou-se como testemunha a madeira de E. grandis. Houve maior ataque do fungo de podridão-parda em relação ao fungo de podridão-branca. Foi observada correlação negativa entre o teor de plástico e o grau de ataque de ambos os fungos. De modo geral, as chapas de madeira-plástico foram classificadas como “altamente resistente” com exceção da proporção com 40% de plástico, que foi classificada como “resistente” ao ataque do fungo de podridão-parda. O índice de susceptibilidade de degradação (DSI) calculado, que leva em conta a densidade do material e a perda de massa real, mostrou que os compósitos foram mais resistentes que a madeira utilizada como referência.

Chapas de partículas de cimento-madeira foram confeccionadas com a madeira de quatro clones de Hevea brasiliensis Müll. Arg. (seringueira): IAN 717, IAN 873, GT 711 e AVROS 1301. Confeccionaram-se as chapas na proporção de 1:4:1 (madeira:cimento:água) por peso e nas dimensões de 450 x 450 x 13 mm e densidade nominal de 1,4 g/cm³, com a adição de 4% de cloreto de cálcio di-hidratado (CaCl2.2H2O) como acelerador. Foram testadas partículas fervidas e não-fervidas dos quatro clones, totalizando oito tratamentos, sendo em cada um destes, com quatro repetições, avaliadas as propriedades mecânicas e físicas das chapas, segundo a norma ASTM D 1037 - 96a. De forma geral, os melhores resultados de propriedades físicas e mecânicas foram obtidos nas chapas com partículas do clone AVROS 1301. No teste de hidratação do cimento, a madeira de seringueira in natura foi classificada como de "inibição extrema", porém com a adição de CaCl2 o foi como de "baixa inibição". Essa madeira se mostrou tecnicamente viável à produção de chapas de cimento-madeira, independentemente do clone.

Cement-bonded particleboards of rubberwood were manufactured with four clones of Hevea brasiliensis Müll. Arg. (rubberwood): IAN 717, IAN 873, GT 711 and AVROS 1301. Boards of 450 x 450 x 13 mm were manufactured in a ratio of 1:4:1 (wood/cement/water), weight basis, with 1.4 g/cm³ density and 4% calcium chloride dihydrated - CaCl2.2H2O as accelerator. The particles of four clones were tested in treated and untreated conditions, totaling eight treatments. In each treatment with four replicates, the physical and mechanical properties were evaluated according to ASTM D 1037 - 96a standard. Overall, the best mechanical and physical results were obtained with the cement-bonded particleboard made with particles from clone AVROS 1301. Rubberwood has shown to be "highly inhibitory" in the hydration test, however when CaCl2 was added the inhibition index decreased and was classified as "low inhibitory". Rubberwood is technically feasible to make cement-bonded particleboard.

ABSTRACT This work utilized wood chips residues of Eucalyptus grandis Hill ex Maiden, and recycled plastic pellets (PEBD), in mixtures with 40%/60%, 50%/50% e 60%/40% of wood/plastic in the composite. It was observed difference among the densities of the treatments. To eliminate this source of variation an analysis of covariance was conducted, with the density as covariate, to make a correct interpretation of the results. Those treatments with a higher proportion of plastic presented a better performance. Overall, most results of the mechanical properties reached the minimum values specified by the ANSI A208.1 standard, except for MOR and MOE in the treatment where a smaller amount of plastic was used.

RESUMO Neste trabalho foram utilizados resíduos de madeira de Eucalyptus grandis em forma de cavacos e plástico pós-consumo tipo polietileno de baixa densidade (PEBD), nas proporções de 40%/ 60%, 50%/50% e 60%/40% de madeira/plástico no composto. Foi observada uma diferença entre a massa específica aparente (MEA) dos tratamentos, sendo necessário realizar uma análise de covariância em função da densidade para a correta interpretação dos resultados. Os tratamentos com maior percentual de PEBD na sua composição foram os que apresentaram melhor desempenho. De forma geral os valores das propriedades mecânicas atingiram os requisitos mínimos da norma ANSI A208.1, usada para classificar chapas de aglomerado, com exceção do MOR e do MOE do tratamento onde uma menor proporção de plástico foi usada.

ABSTRACT Wood-Cement bonded particleboard made with particles treated with CCA were compared with the control, without treatment, as for the inhibition index and physical-mechanical properties. The results showed the technical viability of the production of panels with particles of rubberwood (Hevea brasiliensis Müell. Arg.) treated with CCA. The preservation process was highly significant in the improvement of the boards quality (as detected by the hydration index). All the properties reached the specifications for this type of panel.

RESUMO Chapas de cimento-madeira confeccionadas com partículas tratadas com CCA foram comparadas com chapas controle (sem tratamento) quanto ao índice de inibição e suas propriedades físicomecânicas. Os resultados mostraram a viabilidade técnica da produção de chapas cimento-madeira com partículas de seringueira (Hevea brasiliensis Müell. Arg.) tratadas com CCA. O processo de preservação influenciou significativamente nos resultados, contribuindo para a melhoria de qualidade das chapas (como detectado pelo teste de compatibilidade). Todos as propriedades alcançaram as especificações para este tipo de painel.