Effect of web configuration and flange type on bending strength of I-joist beams

Bending strength of I-joist lightened via two methods of crinkleing and honeycombing using poplar species (Popolus deltoids) and eucalyptus (Eucalyptus spp) was studied. Investigated variables consisted of: a) type of flange, b) configuration of lightened core layer in web and c) thermal-pressure treatment surface layers of web. Flange type at two levels: 1) LVL from poplar wood and 2) eucalyptus massive wood, configuration of web core layer at two level too: 1) crinkle and 2) honeycomb and type of treatment applied on surface layers of web which were prepared from poplar layies with 3 mm thick at two levels: 1) thrmo-compressed treated and 2) untreated veneers were selected. Mechanical properties of beam consisted of modulus of rapture (MOR) and modulus of elasticity (MOE) were selected and tested as dependent variables. Obtained results were analyzed in full factorial plot, statistically. After determination of results significance results, means of values were classified by Duncan Multiple Range Test (DMRT). Results showed that using LVL from poplar unlike its low density had higher MOR and MOE values compared with eucalyptuse massive wood. Besides, in order to lighten beam, using honeycomb configuration in web core layer gave more strength to beam in comparison with crinkle configuration. Treatment of surface layers of web had not effect on bending strength, statistically.