Viabilidade técnica e econômica do tratamento preservativo da madeira de algaroba (Prosopis juliflora (Sw) D.C.), pelo método de substituição de seiva.

Abstract

The woods of good natural durability are rareness and less durable species have been used in environment rural. This research aimed to evaluate the efficiency of sap displacement method in penetration, distribution and retention of commercial "Osmose CCB" preservative in Prosopis juliflora (Sw) D.C. round pieces; to investigate appropriated times and concentrations to P. juliflora wood treatment; and to analyze the technical and economical viability of treatment in rural property. The pieces were submitted to 1; 2 and 3% of CCB solutions during 3, 6, 9, 12 and 15 days. The distribution and penetration of copper and boron elements were analyzed in disks taken in 5 positions in pieces, as well as the retention in 3 positions (ground contact area, half and top of pieces). In these work was observed a better distribution, penetration and retention of CCB in wood exposed to 2% CCB solution. The element boron presented a satisfactory penetration and homogeneous distribution in all positions, concentrations and analyzed times. In function of copper and boron penetrations and CCB retention, the submitted pieces to 2% CCB solution, during 15 days, are able to ground contact uses. The treatment of P. juliflora wood is technically viable for easiness of application of method in rural property and economically viable, when compared the Annual Equivalent Costs (AEC), to discount rates of 3; 9; and 15% and expectations of service life from 16 to 30 years. The P. juliflora treated wood presented smaller AEC to Mimosa caesalpiniifolia wood. The P. juliflora treated wood, with life in service of 30 years, and Mimosa tenuiflora of 5 years, to a discount rate of 3% to year presented smaller AEC to M. tenuiflora, this condition justifies the employment of P. juliflora treated wood.