Bamboo-timber Composite Systems: A Systematic Meta-analysis of Performance, Modeling, and Reliability-based Design

Abstract

A thorough review was conducted of the research published within the past ten years regarding bamboo-timber composite (BTC) structures through a comprehensive meta-analysis on the following topics: experimentation and testing; analytical modelling methodology; and reliability-based design methods. As part of this analysis, the author reviewed and compiled all 32 published results. Based upon experimental review, it has been determined that BTC structural systems have flexural strengths averaging 115–145 MPa, composite action efficiencies which average anywhere from 72% to 78% and a similar level of performance to timber-concrete composites along with significantly improved sustainability profiles. Hybrid Mechanical˗Adhesive Connector (HMAC) connection performance contributes significantly to global performance characteristics, highlighting the high shear strength, stiffness, and ductility of HMAC connections. Hybrid mechanical-adhesive connectors exhibit superior properties relative to traditional mechanical connections, with maximum shear strength exhibiting values equivalent to 110-140kN, stiffness in the range of 16-22 kN/m, and ductility being characterized by the highest values of elongation under tension greater than or equal to 5.5 mm. When evaluating analytical methods for predicting connection performance for HMAC connections, there are significant differences in the accuracy of analytical models developed using coupled nonlinear finite element models with interface slip analysis (94.2%) versus surrogate-assisted probabilistic model approaches. The reliability-based design optimization performed as part of this research identified target reliability indices for the HMAC connection design in the range of 2.1 to 3.3 by demonstrating that 18-24% material savings can be achieved relative to a traditional deterministic design approach. A long-term performance assessment (5-year study) of the HMAC connection performance identified significant degradation of flexural strength and stiffness due to the influence of time-dependent environmental variables. The results of this analysis demonstrate that design models incorporating these environmental factors including creep and connection relaxation are necessary to provide accurate estimates of performance characteristics and necessary basic performance metrics to establish and develop standard test methods and reliable design guidelines for the implementation of bamboo˗timber composite systems in sustainable structural engineering.