Experimental study on Mode Ⅰ fracture characteristics of laminated flattened-bamboo lumber combined with VIC-3D system

•The Mode Ⅰ fracture toughness of a new green construction material—laminated flattened-bamboo lumber (LFBL) were tested.•The effects of the ratio of initial crack length to width and specimen thickness were considered.•The macroscopic and microscopic damage patterns were analyzed, and the recommended dimensions for the tests were proposed.•The strain evolution and crack extension were observed using the VIC-3D system, and a functional equation describing the relationship between compliance and crack length was fitted.