Behavior of center-bored round timber beams in center-point bending test

Abstract

Due to the lack of large cross-section wood, the concern regarding the utilization of small-diameter logs from forest thinning has increased as a worldwide issue recently. Round shape is advantageous to efficient use of small-diameter logs, there is a difficulty of drying and preservative treatment. It is necessary to apply a new technique. In this study, center-boring technology was applied to improve the efficiency of manufacturing. The effect of a hole was not expected to make a significant effect on the flexural performance because the hole is located at the centroid of beam under bending moment. Unlike a round timber beam, the failure of center-bored round timber beam starts with a crack and is followed by a longitudinal split. When designing center-bored round timber as guardrail beam, additional strength reduction by flattening should be considered.