Malaysian standard (MS 544: Part 2) adopted is BS528 for design code. However, the data in MS 544: Part 2 were developed by testing small sample without defect known as small clear sample, whereas the data published in BS5268 were tabulated based on large size tested samples. Therefore, this study investigated the bending strength properties of selected timber of different strength groupings (SG), namely Resak (SG 4), Kapur (SG 4), Merpauh (SG 4), Bintangor (SG 5), White Meranti (SG 5) Jelutong (SG 6), Sesendok (SG 7), and Kelampayan (SG 7) using structural size timbers. Small clear specimens were also tested for bending strength which was used to correlate with data from large size specimens. Bending tests were performed in accordance with BS 373: 1957 and ASTM D-198, respectively. The results showed that the groupings of the timber have been changed when using large size specimens.

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One of the major concerns of wood plastic composite for outdoor application is moisture absorption and thickness swelling (TS). This study investigates the effect of temperature on moisture absorption and TS characteristics of kenaf reinforced polyethylene composite (KPeC). The kenaf materials (core and bast) are at a ratio of 60:10 and were treated with 10 % magnesium chloride (MgCl2). For the preparation of composites, the weight ratio of the kenaf filler (containing core and bast) to high-density polyethylene matrix was 70:22 (wt./wt.), and the weight of the coupling agent in the formulation was 3 wt. %. The composites were prepared using a hot compression molding. The effect of temperature and humidity on the properties of the KPeCs were determined following conditioning at different temperature and relative humidity (RH) combinations, namely 20°C-95%RH, 30°C-95%RH, 50°C-95%RH, and soaking in water at 20°C. The KPeCs were conditioned at various combinations of temperature and RH (20°C-95%RH, 30°C-95%RH, 50°C-95%RH, and soaking in water at 20°C) and the effects of these various conditions on the properties of KPeCs were determined. At 95% RH exposure, the moisture absorption and swelling rate of both composites increased as the temperature increased. All KPeCs at different exposures exhibited Fickian behavior except for KPeCControl and KPeC10%-MgCl2 when aged at 20°C-95%RH.

The shear strength of timber joists in timber design is important, especially to provide an adequate torsional stability and to avoid vibrational serviceability problems. In Malaysia, the data of shear strength of timber is available in MS544 Part 2. The data were developed by shear block test with small samples without defect known as small clear samples. Torsion test is one of the other approaches that can be used to attain the state of pure shear as it does produce a purer and a clearer shear stress distribution in the specimen, allowing measurement of the pure shear properties. However, in Malaysia, very little attention has been paid to the use of the torsion test in evaluating shear strength. Therefore, this study aims to investigate the torsional shear strength of selected Malaysian tropical timbers of different strength groupings (SG) namely Balau (SG1), Kempas (SG2), Kelat (SG3), Kapur (SG4), Resak (SG4), Keruing (SG5), Mengkulang (SG5), Light Red Meranti (SG6), and Geronggang (SG 7) using structural size timbers in accordance with BS:EN 408 and then compared with published by MS554: Part 2. The result shows contradictions of strength grouping between findings and published by MS554: Part 2. Resak (SG4) and Mengkulang (SG5) grade stress value have risen towards SG 3. Geronggang is currently in the SG6. Also from the findings, Kelat (SG3), Kapur (SG4) and Keruing (SG5) grade stresses are at par towards each other, even though they are completely in the different strength group as stated in MS544: Part 2. In conclusion, shear strength data need to be re-examined, since the strength for the tested specimen is much higher than the data given in MS 544 Part 2. This will lead to the increment in section and wastage in cost.

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