Performance of glue laminated timber beams composed of sengon wood (Albizia falcatara) and coconut wood (Cocos nucifera) with nylon-threads reinforcement

Abstract

This paper aims to describe the performance of mix-glue laminated timber beams that are given a nylon strapping as external reinforcement with the three-point bending test to three groups of beams based on the span-to-depth ratio, i.e.: G11, G8, and G5 groups. Each group consists of three types of lamination compositions, namely: Type I, whole lamination consists of sengon wood; Type II, the placement of the coconut wood lamination as the outermost; Type III, similar to type II with added nylon straps with a distance of 5 mm. The bending test results show differences in elastic modulus, flexural strength and shear strength of the glue-laminated timber beams. Based on the comparison of glulam beams consisting of six laminations of sengon wood it was found that the placement of the coconut wood as the outermost lamination succeeded in increasing the elastic modulus, the flexural and shear strength of beams by 28%, 13%, and 34%, respectively. In addition, the reinforcement with nylon straps results in the modulus of elasticity, bending and shear strength of glulam to increase by by 41%, 2%, and 49% respectively.