TESTING OF MODELS OF ORIGINAL AND UPGRADED CONNECTION BETWEEN RC FLOOR-BEAM AND COLUMN USED IN MODERN PRECAST HALL SYSTEM

Abstract

The design and construction of modern, globally upgraded and seismically safe industrial hall systems (SSIH Systems) is currently viewed as an activity of extraordinary importance since these structures most frequently house new advanced and robotically conceptualized industrial machines and equipment, whose value multiply exceeds the value of the integral structures. The SSIH systems are of vital importance because it is only by their practical application that efficient and continuous functioning of important production industrial systems and compounds is provided. The achieved safety margins, the actual seismic performances and the present limitations of the used pin-based floor-beam column connections of the existing precast N-system were integrally confirmed by the original results obtained from the conducted experimental tests of the constructed connection prototype models. The precast N-system is commonly used for intensive construction of large industrial structures in different regions and countries, including areas of Europe and wider characterized by high seismicity. The initial results obtained from the laboratory test of the constructed large-scale prototype model representing a common floor-beam column (CFBC) connection confirmed the actual bearing capacity of the connection, the damage propagation pattern and the specific total failure mode. To investigate possible upgrading of the connection safety, a specific supplementary test was performed using the created and constructed new experimental model, representing an upgraded floor-beam column (UFBC) connection by application of an improved concrete confinement and use of larger diameters of steel connection pins (dowels). The main conclusion regarding the safety increase was that such common upgrading concept of pin-based connections could not be considered as a basic adequate approach since it was able to provide only limited upgrading effects. The existing need for creation of a new, advanced, experimentally proved and effective innovative upgrading method was clearly pointed out.