Study of modulus of rupture, circumference taper, sapwood thickness and CCA treatment of Norwegian origin Pinus sylvestris poles

IRG/WP 94-20054

A K Lahiry, S Begum, G N M Ilias, M A B Fakir, R U Hafiz

Nondestructive strength testing with Pilodyn (6J) of Norwegian Pinus sylvestris poles revealed effective modulus of rupture (MOR) of 54.39 N/mm² at wet conditions after CCA-C treatment and circumference measurement revealed circumference taper of 0.021 m/n. Sapwood thickness or penetration of CCA-C study revealed that 77% poles were with sapwood thickness equivalent to 39.6% of radius of poles and above, 72% poles were with sapwood thickness equivalent to 40% of radius of poles and above and 59% poles were with sapwood thickness equivalent to 44% of radius of poles and above. Noted that 19% poles were within the sapwood thickness range of 39.6 to 40% of radius of poles and 14% poles within the sapwood thickness range of 40 to 44% of radius of poles. Proper selection of poles before and after preservative treatment regarding desired sapwood thickness would eliminate undesirable poles for REB. X-ray spectroscopic analysis revealed mean retention of dry oxides of CCA-C of w/v 20.58 kg/m³ sd 2.53 (w/w 4.28% sd 0.52) in an assay zone of 2.5 to 45 mm. Regular maintenance of chemical balance of individual component of CCA-C before preservative treatment would be more suitable to have balanced retention of individual component of CCA-C.