Flexural behavior of composite section of multiple full-culm bamboo beams with mortar infill bolted joints

Abstract

Full-culm bamboo has several characteristics that make it an excellent alternative construction material due to its rapid growth rate, high strength-to-weight ratio, and high carbon sequestration. Thus, it becomes crucial to study the mechanical and structural performance of bamboo within an engineering framework, such as flexural behavior of multi-culm elements, since it is a key issue of typical elements of building such beams, joists, and others. While there is a general understanding of the composite section behavior in materials such as timber, steel and concrete, there is a lack of experimental evidence concerning bamboo in this regard. Therefore, an experimental program was undertaken by the Center of Research in Materials and Civil Works (CIMOC) at the Universidad de Los Andes in Colombia. Two- and three-culm elements of Guadua angustifolia Kunth from a Colombian plantation using a Bolted-Mortar Infill connections were tested in a bending setup. The gamma method, extensively employed in timber standards, was used to find the percentage of composite section for different number of shear connectors. Montecarlo simulations were performed to deal with uncertainty of the modulus of elasticity and the slip modulus (stiffness) of the Bolted-Mortar Infill connection. Additionally, a design factor FI was proposed that allows to find the ratio of increment of the effective moment of inertia of partially composite section for different connection configuration. Equations were derived and proposed for C and FI through linear regression.