<p>Accurate prediction of normal contact behavior for rock joints is essential for understanding the interfacial physical properties and multi-physics coupling processes within jointed rock masses. However, the available Hertzian-based contact models generally overlook the effects of elastoplastic and full plastic deformation across the whole topography. Here, a new normal closure deformation model is proposed to evaluate the contact characteristics of rock joints. The geometrical characteristics of asperities on rock joints are characterized by fractal theory to capture the topography across different wavelengths. Through numerically investigating the influence of topography and mating degree on the size distribution of geometrically overlapping patches, and using the digital image process technology for quantification, a new size distribution law that incorporates the fractal dimension is developed. The closure deformation of a single asperity during the transition from elastic, through elastoplastic, to full plastic deformation is analyzed based on fractal theory. New elastoplastic contact model for rock joints is finally constructed based on the new size distribution of geometrically overlapping patches using a statistical method, which is validated by the closure tests on sandstone joints. Compared to the Greenwood and Williamson model, the predictions by the new model are closer to the experimental results. Sensitivity analyses of the morphological and mechanical parameters of rock joints revealed that the fractal dimension, amplitude parameter, and hardness are key factors influencing contact behavior. Finally, the limitations of the proposed model are discussed.</p>