Distribution of Forces in Reinforcing Bars in Slab-Column Connections of RC Structures
The article deals with the analysis of the problem of the load-bearing capacity of reinforcing bars placed above the columns in slab-column connections of reinforced concrete structures. Failure of the support zone by punching and lack of proper structural integrity reinforcement can lead to a progressive collapse. The EC2 standard guidelines recommend the use of integrity reinforcement, however, they lack any instructions concerning the amount of necessary reinforcement. The article presents a theoretical calculation model that permits a more detailed analysis of internal forces in reinforcing bars located directly above the column. Adopting a solution in the form of exact equations makes it possible to take into account the influence of a non-linear change of the bar stiffness and considerable deflections. The calculation model is based on the results of experimental investigations. On the basis of a theoretical model it is possible to estimate the tensile force of the bar at which the bars located directly in the support zone are ruptured.