Analysis of mechanical properties and failure mechanism of bamboo aggregate concrete

Abstract

Bamboo Aggregate Concrete (BAC), as a novel construction material, has garnered attention due to its environmental sustainability. However, research on the mechanical properties and failure mechanisms of all-bamboo aggregate concrete is yet to be seen. This study first investigates the mechanical properties of BAC materials through experimental and numerical simulation methods, observes the interface characteristics between bamboo aggregate and mortar using Scanning Electron Microscopy (SEM), and quantifies the transition zone range using nanoindentation technology. Finally, the micro-morphology of the failure interface is observed. The study reveals that the 7-day compressive strength of BAC material can reach 84.8% of its 150-day strength, while also displaying significant mechanical anisotropy. The strength range of the BAC mortar matrix is suitable to be between M10 and M35. The toughness of BAC material is five times that of conventional concrete, and its comprehensive performance is optimal when the water-cement ratio is 0.50. The interface between bamboo aggregate treated with the AP method and the mortar matrix exhibits good adhesion, with an Interfacial Transition Zone (ITZ) thickness ranging approximately between 245μm and 300μm. The failure of BAC material mainly initiates from the ITZ area, forming cracks that extend and lead to the debonding of bamboo aggregate and mortar matrix, ultimately causing overall failure. This research unveils for the first time the material characteristics of full bamboo aggregate concrete, which holds significant importance in promoting the extensive use of bamboo aggregate, reducing the extraction of gravel, and lowering carbon emissions.