Authors:Bilshan Servañez, F; Ramon Razal, A; Elvira Fernandez, C; Myrna Carandang, G; Menaadro Acda, N
Abstract:Culturally preformed Bayog (Bambusa merrilliana (Elmer) Rojo & Roxas comb. nov.) syn. (Dendrocalamus merrillianus (Elm.) Elm.) culms from a plantation in Dumarao, Capiz, Philippines were examined for their mechanical and physical properties. The mechanical properties and the corresponding mean values are as follows: maximum load carried in bending, 1.92 tons; load at proportional limit, 1.16 tons; stress at proportional limit, 84.48 MPa; modulus of elasticity (MOE), 3.94 GPa; and modulus of rupture (MOR), 138.90 MPa. The bends in the upper portion of the culms had significantly higher mechanical property values than the bends in the lower portion. The physical properties of bent Bayog culms are as follows: average specific gravity is 0.45 and the mean moisture content is 112.0% at the inner radius and 114.5% at the outer radius of each bend. Shrinkage values also differed depending on the location along the arc of the bent culm wall. The average shrinkage values across the culm wall were 5% and 4.45% for the inner and outer radii, respectively; while the respective volumetric shrinkage values were 9.73% and 8.19%, suggesting that the inner culm wall was more prone to dimensional changes as moisture content changes. Mean longitudinal shrinkage value was 0.23% which was slightly higher than normal culms. Mechanical properties were found to be positively correlated with culm diameter, outer radius and specific gravity but were negatively correlated with length of internodes and moisture content. The findings suggest that cultural preforming of Bayog does not adversely affect its mechanical properties and that the resulting preformed poles could meet the strength requirements for load-bearing structural and engineering applications
Keywords:Bayog (Bambusa merrilliana), culm, culturally-preformed, physico-mechanical properties