Experimental evaluation and theoretical modeling of eco-friendly bamboo scrimber-UHPC members with enhanced shear connectors

Timber-Concrete Composite (TCC) systems are applied widely in bridges and buildings. This study innovatively combines the eco-friendly attributes of Bamboo scrimber with Ultra-High Performance Concrete (UHPC) to develop TCC systems, leading to the formulation of Bamboo scrimber-UHPC (BS-UHPC) composites. These composites are designed to boost both mechanical behaviors and environmental sustainability. The research conducts an extensive analysis through eight series of push-out tests on BS-UHPC systems, employing diverse shear connectors such as notches, inclined bolts, and stencils. It provides an in-depth examination of the failure mechanisms, detailing general load-slip behaviors and analyzing the progression of failure. The findings reveal the influence mechanism of UHPC and shear connectors on the mechanical properties and failure modes of these composites, with notched shear connectors demonstrating the highest shear capacity with 134 kN. Additionally, the study explores the efficacy of notch connections through finite element models for parametric analysis, enabling a quantitative assessment of concrete cracking areas. Building upon these insights, the research proposes and validates theoretical models for predicting the shear capacity of these composites. Moreover, this paper employs life-cycle assessment to evaluate the environmental impact, specifically CO2 emissions of the BS-UHPC composites within service life, comparing them with those of traditional timber-ordinary concrete and steelordinary concrete systems. The results indicate that BS-UHPC composites offer significant improvements in mechanical behaviors while also achieving the lowest CO2 emissions with 78 kg CO2-Eq/m3 among the materials tested. This positions BS-UHPC composites as an advantageous choice for practical engineering applications.