Takashi Nakai, Alik Duju & Hirofumi Nagao Preliminary Study for Strength Grading of Tropical Hardwood in Sarawak
To cope with the large number of species and difficulties of identification of tropical hardwood, development of strength grading would be highly needed for effective structural use of tropical hardwood. The relationship between modulus of elasticity and modulus of rupture in full size structural member was examined. The sizes of specimen were 50mm and 100mm in width, 100mm in height and 2000mm in length. After measuring the fundamental frequency at longitudinal vibration, Efr was calculated. The one third two-point loading system was used for bending test with a 1800mm total span. The Eapp and Etrue were obtained. The total 398 specimens from nine tropical hardwoods were tested in green condition. Any modulus of elasticity could be used to predict modulus of rupture, however Efr was regarded as the most suitable one for practical use.