Critical Points of Prefabricated Reinforced Concrete Wall Systems of Multi-storey Buildings

With respect to the dissipation of energy through plastic deformation of joints of prefabricated wall units, the paper points out the principal importance of efficient reinforcement of the prefabricated system at its joints. The method, quality and amount of reinforcement are essential for reaching the necessary degree of joint ductility. The paper presents partial results of experimental research of vertical joints of prefabricated units exposed to monotonously rising loading and repetitive shear force and formulates a conclusion that the limit state of the structure as a whole is preceded by the disintegration of joints, or that the structure tends to pass from linearly elastic behaviour to non-linearly elastic to plastic behaviour by exceeding the proportional elastic limit in joints.Experimental verification on a model of a 7-storey prefabricated structure revealed weak points in its load-bearing systems, mainly at places of critical points around openings situated in close proximity to vertical joints of mutually perpendicularly oriented walls. Keywords—dissipative energy, dynamic and cycling load repetitive load, working diagrams of joints I. CRITICAL POINTS AND DISSIPATIVE ENERGY OF PREFABRICATED REINFORCED CONCRETE WALL SYSTEMS The reliability and structural safety of prefabricated reinforced concrete wall systems exposed to extraordinary effects (explosion, fire, acts of terrorism) and dynamic effects (technical and induced seismicity, natural seismicity) rely on the plastic deformation mechanism of mainly the joints of load-bearing prefabricated members with simultaneous dissipation of energy. At this phase of the prefabricated loadbearing reinforced concrete wall systems’ action, absorption of energy occurs, and the necessary condition at this phase of the bond’s action (plastic action phase) is that the respective structural bond must not be completely eliminated from the load-bearing system. This presumes that the plastic deformation mechanism must prevail at critical points of the bearing system during the dissipation of energy. In the case of prefabricated wall systems, it is the vertical joints of prefabricated wall units exposed mainly to shear forces and the floor slab stiffness binding individual vertical wall Jiri Witzany, Czech Technical University in Prague, Faculty of Civil Engineering, Department of Building Structures, Prague, Czech republic, Thakurova 7, 16029 Prague, Czech republic (phone +42