Wood-plastic composite (WPC) is a kind of composite material made from a mixture of natural plant materials such as wood fibers or wood powder and special additives. The compressive strength is one of the main mechanical properties of WPC, which can be influenced by many factors. In this paper, the size effect is investigated by testing WPC specimens with proportional size and the same cross-section and different heights. The effect of specimen size on load bearing capacity, deformation capacity and strain distribution was analyzed. Based on the test data, three groups of stress-strain models for WPC were proposed. Based on Weibull brittle fracture theory, the relationship between the volume (height) parameter and compressive strength is calculated and analyzed by the parameter method, which can serve as a reference for research in related fields.

Wood-plastic composite, compressive strength, size effect, axial compression