The aim of the paper is to show the common characteristics of the main contributions of Roger Boscovich, Milutin Milanković and Branko Žeželj to the development of civil engineering. Through contributions of Boscovich, Milanković and Žeželj, the continued development of civilization is overlooked in which theories and practices are intertwined. Bošković and Milanković are linked by theoretical approach and successful application of theory in solving practical problems in civil engineering, while Milanković and Žeželj are linked by an unique approach to the technology of building concrete structures. Besides this, a chronological review of the patents of Žeželj and Milanković in the field of civil engineering is covered, as their patents were successfully applied in the construction of concrete structures. In addition, a typology of all patents of Branko Žeželj is given by field of application, thus illustrating Žeželj's contribution to the technology of construction.
Keywords: Roger Boscovich, Milutin Milanković, Branko Žeželj, reinforced concrete ,civil engineering, structure, prestressed concrete, invention, patent, theory of elasticity, civil construction technology