VARIASI AKSIAL DAN RADIAL STRUKTUR ANATOMI DAN SIFAT FISIKA-MEKANIKA KAYU MERBAU (Intsiabijuga) ASAL KEROM-PAPUA

DONY ARISTONE DJITMAU, Prof.Dr.Ir.Sri Nugroho Marsoem, M,Agr.Sc.;Dr. Joko Sulistyo, S.Hut., M.Sc.

2017 | Tesis | S2 Ilmu Kehutanan

Studi variasi aksial dan radial sifat fisik-mekanik dan struktur anatomi kayu merbau dilakukan menggunakan tiga pohon dengan diameter setinggi dada (dbh) ratarata 34 cm. Ketiga pohon tersebut tumbuh di hutan alam berdasarkan pada kedudukan aksial dan radial. Pengambilan log kayu sepanjang 80 cm dipotong pada bagian batang dari pangkal ke ujung sampai batas cabang pertama. Pengujian sifat fisik; kadar air, berat jenis dan perubahan dimensi, sifat mekanik; keteguhan lengkung statis MOE dan MOR, keteguhan tekan sejajar serat, keteguhan tekan tegak lurus serat, keteguhan geser dan kekerasan. Struktur anatomi; proporsi sel, dimensi serat. Data dianalisa dengan analisis varians yang menggunakan rancangan acak kelompok dalam faktorial. Penelitian ini bertujuan untuk mengetahui variasi aksial dan radial sifat fisik-mekanik dan struktur anatomi kayu merbau yang terjadapat di Kabupaten Kerom-Papua untuk kemungkinan penggunaan yang sesuai. Hasil penelitian menunjukkan bahwa kayu merbau mempunyai rerata kadar air segar dan kering udara sebesar 77,45 % dan 12,92 %. Berat jenis segar, berat jenis kering udara, berat jenis kering tanur sebesar 0,66, 0,69, dan 0,73. Penyusutan tangensial, radial dan longitudinal dari segar ke kering udara sebesar 2,89 %, 1,50 % dan 0,21 %. Pengembangan tangensial, radial dan longitudinal dari kering tanur ke basah sebesar 5,24 %, 3,07 %, 0,38 %. Keteguhan lengkung statik MOE dan MOR sebesar 13.300 Kg/cm2 dan 103,10 Kg/cm2 . keteguhan tekan tegak lurus serat dan keteguhan tekan sejajar serat sebesar 243,14 Kg/cm2 dan 532,31 Kg/cm2. Keteguhan geser dan kekerasan sebesar 89,77 Kg/cm2 dan 1001,88 Kg/cm2. Struktur anatomi proporsi sel ; pembuluh 9,03 %, serabut 53,63 %, jari-jari 15,73 %, parenkim 22,72 %. Panjang serat 1,39 mm, diameter serat 26,39 um, diameter lumen 15,44um, tebal dinding sel 5,64 um. Secara umum pola penyebaran sifat fisik-mekanik dan struktur anatomi kayu merbau pada arah aksial dan radial yang terbentuk sangat bervariasi. Kayu merbau ini sudah memenuhi syarat penggunaan baik sebagai konstruksi ringan maupun berat, dapat digunakan baik dibawah atap bangunan maupun luar. Bahkan dipendam sebagai konstruksi jembatan, lantai, kusen, jendela, pintu, tiang pagar, tiang pelabuhan dan lain sebagainya

Study of wood properties in term of mechanical and anatomical characteristics was done with axial and radial direction of wood obtained from three trees with dbh about 34 CM. Samples were taken from bottom of each tree up to first branch around 80 CM. The tests were physical aspect, water content, wood mass, dimensional change, mechanical aspect, straight test of MOE and MOR, strength of fibre same and perpendicular direction, and its stability. Moreover, anatomical structure, cell proportion as well as fibre dimension were measured as well by applying analysis of variance. The results revealed that the average fresh and dried water content were 77.45 % and 12.92 % respectively. Fresh weight, dried weight and oven dried weight were 0,66, 0,69 and 0,73. Tangential, radial and longitudinal change were 2,89 %, 1,50 % and 0,21 %, while the dimensional change using oven for tangential, radial and longitudinal direction were 5,24 %, 3,07 % and 0,38 %. Static strength with MOE dan MOR were 13.300 Kg/cm2dan 103,10 Kg/cm2. The strength of perpendicular and parallel directions were 243,14 Kg/cm2and 532,31 Kg/cm2. Strength and hardness of wood were 89.77 Kg / cm2 and 1001,88 Kg / cm2. The anatomical structure of cell proportions consisted of:vessel was 9.03%, fibrewas 53.63%, radius was 15.73%, and parenchymawas 22.72%. The fibre length was 1.39 mm, the fibre diameter was 26.39 um, the lumen diameter was 15.44 um, the cell wall thickness was 5,64um. In general, the pattern of dispersal of physical-mechanical properties and the anatomical structure of Merbau wood in the axial and radial direction formed varies greatly. Merbau wood in this study was qualified for both light and heavy construction such as the roof of the building or outside like the construction of bridges, floors, frames, windows, doors, fence posts and port poles.

Kata Kunci : : Merbau (Intsiabijuga), sifat fisik, sifat mekanik, struktur dan anatomi;Merbau (Intsiabijuga), physical properties, mechanical properties, structure and wood anatomy.