Qualidade de moirões tratados com diferentes concentrações de CCA-C

Abstract

This study aimed reduce CCA concentration established by NBR 9480 (ABNT, 2009), without affecting the quality of treated posts. Eucalyptus cloeziana (seminal origin) and E. urophylla x E. camaldulensis (clonal hybrid) from commercial plantations, at the age of six years were used. 25 posts with length of 2.20 m and diameter of 8 to 10 cm, randomly collected in drying cells were picked for each genetic material. The basic density, moisture, sapwood percentage and the treatable volume were determined, besides characterizing anatomical structure. The materials were treated with concentrations of 1.2%, 1.3%, 1.4%, 1.5% and 1.6% of CCA-C active ingredients. The quality of the preservative treatment was evaluated by means of penetration and retention and toxicity (treated wood) to termites by means of food preference test with Nasutitermes corniger Motsch. The treated wood of E. cloeziana presented 44% of the posts with partial and regular penetration, 40% with partial and irregular penetration, 12% with deep and irregular penetration and 4% with zero penetration. The clonal hybrid presented 68% of the posts with deep and regular penetration, 24% with deep and irregular penetration and 8% as partial and regular penetration. The concentrations of 1.4, 1.5% and 1.4, 1.6% of active ingredients for, respectively, E. cloeziana and clonal hybrid reached the minimum retention according to NBR 9480 (ABNT, 2009). In both genetic materials, the highest values of mass loss were in the controls that did not receive preservative treatment. The damage on both genetic materials was classified as "undamaged, allowing superficial scarifications".