Comparative assessment of load-bearing capacities in bolted laminated bamboo lumber connections: A study on diverse reinforcement techniques

Abstract

Laminated bamboo lumber (LBL), a renowned engineered bamboo composite known for its outstanding performance and sustainability, is extensively used in modern bamboo structured buildings. This study focuses on examining the effects of diverse reinforcement techniques, particularly self-tapping screws and tension control bolts, on the load-bearing capacity of bolted LBL connections with steel plates. In total, 24 specimens were categorized into 8 groups and subjected to monotonic loading tests. The test results demonstrate that the non-reinforced group clearly shows longitudinal splitting failure at the bolt position, followed by a decrease in load-bearing capacity after failure. In contrast, the group with self-tapping screws (ST) and tension control bolts (BT) exhibited fiber tearing at the lower part of the midspan, accompanied by section bending and damage. The final load-bearing capacity of the groups reinforced with single-row three-bolt self-tapping screws and tension control bolts showed an increase of 67.30 % and 52.95 %, respectively. Likewise, the groups with single-row four-bolt configurations also demonstrated significant reinforcement effects, with increases of 40.52 % and 29.66 %, respectively. Furthermore, DIC-3D analysis was employed to examine the displacement of the connection bolts, and the van der Put model was utilized to estimate the load-bearing capacity of bolted LBL connections under splitting conditions. Subsequently, finite element models were established and calibrated based on the experimental data. The results confirm that self-tapping screws and tension control bolts can serve as structural enhancements in the design of bolted LBL connections, providing effective reinforcement for existing engineering structures.