A non-destructive approach for assessing decay in preservative treated wood

Machek, L.; Edlund, Marie-Louise; Sierra-Álvarez, Reyes; Militz, Holger

doi:10.1007/s00226-002-0161-5

Cited by 8 publications

(5 citation statements)

References 3 publications

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“…Soil-block trials commonly result in more variable wood decay and higher threshold values than agar-block trials when testing wood preservatives (Cockroft 1974;Wazny and Cookson 1994;Jamsa and Viitaniemi 1998), particularly those targeting oxidative decay mechanisms (Backa et al 1992;Green and Schultz 2003), and soil type has been shown to affect preservative efficacy (Machek et al 2004). We were not able to fully explain the cause of oxalate decreases in wood during decay, primarily due to variability in our soil-block decay data.…”

Section: Discussionmentioning

confidence: 99%

Oxalate regulation by two brown rot fungi decaying oxalate-amended and non-amended wood

Schilling

Jellison

2005

Holzforschung

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Oxalic acid secretion by brown rot wood-degrading fungi has been proposed to function in pH control and nonenzymatic biodegradation. Although oxalate production in liquid cultures of brown rot fungi commonly correlates with glucose oxidation, excess oxalate accumulation in wood during oxidative decay could impede Fe 3q reduction by fungal-derived chelators and thus inhibit brown rot. In this study, we pre-treated spruce wood with various oxalate concentrations and subjected it to brown rot decay by Fomitopsis pinicola and Meruliporia incrassata in agar-and soil-block trials. In agar-block microcosms containing wood pre-treated with 0, 1, 10 or 100 mM sodium oxalate, test fungi equalized wood oxalate and pH at week 12 of decay by either increasing or reducing wood oxalate, depending on the pre-treatment. Oxalate reductions in wood were not accompanied by increases in agar oxalate. During soil-block decay of wood pretreated with 0 or 50 mM oxalate, oxalate and pH regulation were time-dependent and more variable. Wood oxalate levels did not increase with increasing fungal biomass (per ergosterol); however, decreases in oxalate were not explained by enhanced oxalate catabolism activity, Ca 2q import, or translocation of oxalate into the soil. Our results suggest that brown rot fungi may optimize extracellular oxalate during wood decay, and that soil characteristics may influence this dynamic.

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Section: Discussionmentioning

confidence: 99%

Oxalate regulation by two brown rot fungi decaying oxalate-amended and non-amended wood

Schilling

Jellison

2005

Holzforschung

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“…Lemmens N.V.; Leuven; Belgium). More information about this procedure can be consulted in Hearmon (1966) and Machek et al (2003).…”

Section: Methodsmentioning

confidence: 99%

Bending creep of Maritime pine wood (Pinus pinaster Ait.) chemically modified

Lopes¹,

Mai²,

Militz³

2013

Folia Forestalia Polonica, Seria a - Forestry

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The long-term performance of a structural member is determined by its durability and deformation with time. The bending creep behaviour of modified wood was assessed experimentally over a period of 35 days (840 hours).Four chemical modification processes were used: 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU), mmethylated melamine formaldehyde resin (MMF), tetraethoxysilane (TEOS) and amid wax (WA). Wood stakes with 20 . 10. 200 mm RTL dimensions of Portuguese Maritime pine (Pinus pinaster Ait.) from sapwood part of the stem were used for evaluated the primary creep. Experiments were conducted at bending stresses amounting to 0.1, 0.2, 0.4 of the mean immediate wood bending strength obtained at equilibrium moisture content (EMC). Applying the same stress level (SL, 0.2), wood creep was also determined at the constant low and high moisture content.As results: Between low and medium SL (8 and 16 N/mm 2 ), unmodified wood at indoors conditions did not show any effect in the creep factors (k c ). However, at high SL (35 N/mm 2 ) a slight increase (not significant) in the k c was found. It seems that the k c was nearly independent of the SL.In the lumen fill modification (TEOS and wax), the deposited material has not affected the creep behaviour under various SL.The cell wall modification (with DMDHEU and MMF resins) did not show any differences in the k c for low and medium SL (8 and 16 N/mm 2 ). However, resin modification under high SL (35 N/mm 2 ) has shown a significant reduction related to unmodified wood. Between both types of resin (DMDHEU and MMF) and levels of modification (WPG), significant effect was not found.At saturated conditions, lumen fill modification (TEOS and wax) did not show any effect on creep. In the cell wall modification (DMDHEU and MMF resin), significant reduction was recorded due to the embrittlement effect imparted by the modification (deposit of resin in the cell wall).

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“…A umidade foi ajustada para 80% da capacidade de retenção de água (IPT, 1980). Os corpos de prova foram dispostos verticalmente no solo, com aproximadamente 2 cm de comprimento acima da superfície do solo (MACHEK et al, 2004). Dos 10 corpos de prova utilizados em cada variável, 6 foram soterrados em solo não estéril e 4 em solo estéril, de acordo com método proposto pelo IPT (1980).…”

Section: Ensaio Acelerado De Laboratóriounclassified

Avaliação Do Tratamento Preservativo De Taliscas De Bambu Com Ácido Pirolenhoso

Beraldo¹,

Matsuoka²

2013

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ResumoA baixa resistência natural do bambu ao ataque de organismos xilófagos constitui uma das principais limitações ao seu pleno uso. O objetivo do presente estudo foi avaliar o efeito do ácido pirolenhoso no tratamento preservativo de taliscas de bambu-gigante contra fungos deterioradores. Para tal, foi realizado um ensaio de apodrecimento acelerado em laboratório com taliscas testemunhas (sem tratamento) e taliscas tratadas com o produto diluído em água fervente nas concentrações 0%, 5%, 10%, 20% e 30%, adotando-se tempos de imersão 15, 45, 90 e 180 minutos. As taliscas de bambu foram testadas após 6 e 16 semanas de exposição. Foram efetuadas inspeções visuais nas taliscas e aplicados ensaios não destrutivos de perda de massa e por ultrassom (6 e 16 semanas) e ensaios de flexão estática (após 16 semanas). Os resultados obtidos nos ensaios não destrutivos não evidenciaram o efeito dos fatores testados (tipo de solo, duração do tratamento e concentração da solução) nessas propriedades. A análise visual indicou apenas um ataque superficial nas taliscas, não evidenciando perda de massa. No ensaio de flexão estática, verificou-se o efeito favorável da duração do tratamento nos módulos de elasticidade (E m0 ) e de ruptura (MOR). O tipo de solo (natural ou estéril) não apresentou influência no módulo de elasticidade, enquanto que a concentração da solução não influenciou o módulo de ruptura. Palavras-chave: Bambu-gigante; biodeterioração; fungos deterioradores. AbstractEvaluation of preservative treatment of bamboo strips with pyroligneous acid. Bamboo presents a low natural resistance to decay, which constitutes one of the major limitations to its use. This study aims to evaluate pyroligneous acid effect against fungal bamboo deterioration through an accelerated laboratory decay with testing reference (without treatment) and treated specimens with the product diluted in boiling water at (0%, 5%, 10%, 20% and 30%) in different immersion times (15, 45, 90, and 180 minutes). Bamboo splits were evaluated after 6 and 16 weeks of exposure. Visual inspections and non-destructive tests (mass loss and ultrasound at 6 and 16 weeks) and bending (after 16 weeks) were applied to the bamboo strips. Results of the non-destructive tests did not allow to detect the effect of the factors (soil type, immersion time and solution concentration) on these properties. Only a superficial attack was observed by visual inspection, which did not denote mass loss. Immersion time shows a positive effect on modulus of elasticity (E m0 ) and on modulus of rupture (MOR). Moduli of elasticity and rupture were not influenced by soil type (sterile or natural), or by the concentration of the solution, respectively. Keywords: Giant bamboo; biodeterioration; fungi decay. INTRODUÇÃODe origem asiática, o bambu-gigante, como é popularmente conhecido, apresenta considerável resistência mecânica e excelentes propriedades físicas, como leveza, teor de fibras, flexibilidade e facilidade de trabalho, o que permite seu uso em diversas aplicações. Por se tratar ...

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A non-destructive approach for assessing decay in preservative treated wood

Cited by 8 publications

References 3 publications

Oxalate regulation by two brown rot fungi decaying oxalate-amended and non-amended wood

Oxalate regulation by two brown rot fungi decaying oxalate-amended and non-amended wood

Bending creep of Maritime pine wood (Pinus pinaster Ait.) chemically modified

Avaliação Do Tratamento Preservativo De Taliscas De Bambu Com Ácido Pirolenhoso

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