Shahrood University of Technology Journal of Mining and Environment 2251-8592 14 4 2023 10 01 Specimens Size Effect on Mechanical and Fracture Properties of Rocks: a Review 1273 1293 2771 10.22044/jme.2023.12948.2350 EN Alireza Dolatshahi Department of Mining Engineering, Amirkabir University of Technology, Tehran, Iran. Hamed Molladavoodi Department of Mining Engineering, Amirkabir University of Technology, Tehran, Iran. Journal Article 2023 04 13 The structure's response to the region's prevailing loading conditions guides the engineers in estimating the resilience of the structural materials and their reinforcement. One of the main concerns in designing rock structures is paying attention to the size effect phenomenon. The size effect influences the nominal strength, brittleness, load capacity, stress intensity factor, the characteristics of the fracture process zone at the crack tip, and the way and path of crack propagation. Therefore, studying the size effect law will make a guideline for correct decision-making, design, and implementation of efficient support systems. As a comprehensive review, this work investigates specimen size effect on the rock's mechanical and fracture properties. With a comprehensive look at this issue, it explains the essential points that help the engineers design rock structures. During the investigations carried out in this work, it is shown that the specimen size affects the fracture and mechanical properties of the rock. The severity of this phenomenon depends on various factors such as the brittleness index, the shape of the notch or crack length, and the size of the particles that create the rock. In concrete, it depends on the additive boosting materials in the concrete. https://jme.shahroodut.ac.ir/article_2771_64a3b4c864e125bea88e8ed893d675aa.pdf