QUALITY OF Hovenia dulcis Thunb. ROUND FENCE POSTS SUBMITTED TO PRESERVATIVE TREATMENT

Abstract

This study aimed to test the hypothesis regarding the quality of Hovenia dulcis fence posts, which states that it varies according to the treatment period when subjected to the sap displacement method.. The experiment began with 15 round fence posts distributed vertically in tank containing copper sulfate, sodium dichromate and boric acid (CCB) solution at 2.5% concentration. In order to verify the influence of time on the efficiency of the method, the posts stayed in the preservative solution for periods of 3, 6, 9, 12 and 15 days, which were assessed. Penetration and retention in three positions were analyzed, which corresponded to the regions of base, middle and top parts. With regards to treated wood, samples of each piece were prepared for testing in field test. Then, weight loss and bending properties were assessed. According to the results of penetration and retention, wood treated on the period of 15 days is the only one that can be used directly with the soil. After assessment of the weight loss, the periods of 12 and 15 days of treatment increased the classification of wood from moderately to strong resistant. The bending test showed significant reduction in rigidity and strength of the material, even in the treated ones, which demonstrates that the forest environment in which samples were exposed promoted the process of wood decomposition.

Influence of treatment with water-soluble CCB preservative on the physical-mechanical properties of brazilian tropical timber

“…Wood is a renewable material with physical-mechanical properties that allow its use in various purposes, such as construction, the furniture industry, energy production, paper and pulp. In addition, it has a strong ecological appeal, if proper management is employed in plantation zones 1,2 . Besides, wood presents advantages when compared to other building materials, such as concrete and steel.…”

“…Besides, wood presents advantages when compared to other building materials, such as concrete and steel. Among them, it is possible to mention the beautiful appearance, high mechanical strength, easy workability and is a good thermal and electrical insulation 2,3 . As restriction, one may cite its susceptibility to xylophagous organisms, consequence of their biological origin which leads to moisture retention and, consequently, proliferation of biological organisms that induce its deterioration [4][5][6] .…”

“…When wood is outdoor exposed to environment without going through appropriate preservative treatment, its biodeterioration occurs 7,8 . Wood properties are changed due to physical, chemical, mechanical or biological agents, the latter being xylophagous organisms 2,9 . These organisms attack the natural polymers of wood cell walls, which act as sources of nutrition.…”

Influência da impregnação contra demanda biológica em propriedades físico-mecânicas de madeiras tropicais brasileiras

“…A madeira, material de fonte renovável, possui propriedades vantajosas para a construção civil, como alta resistência mecânica em relação à massa, bom isolamento térmico e elétrico, fácil trabalhabilidade e beleza (VIDAL et al, 2015;SILVEIRA et al, 2018). Como desvantagem, se destaca a suscetibilidade ao ataque de organismos xilófagos, consequência da sua origem biológica que favorece a retenção de umidade e a proliferação destes organismos (MOHAN et al 2008;TEMIZ et al 2010;FERRARINI et al, 2012;TEMIZ et al 2013).…”

“…A deterioração causada pelos organismos xilófagos diminui drasticamente as propriedades de resistência e a durabilidade da madeira (EDLUND; NILSSON, 1998;ISAKSSON;BRISCHKE;THELANDERSSON, 2012;SILVEIRA et al, 2018), pois estes organismos atacam os polímeros naturais, que conferem rigidez às paredes celulares dos elementos anatômicos e proporcionam resistência às solicitações mecânicas e, consequentemente, causam mudanças significativas nas propriedades físico-mecânicas das madeiras (OLIVEIRA et al, 1986;ZABEL;MORREL, 1992;ZIGLIO;GONÇALVES, 2013).…”