Repair and Strengthening of Beam-to-Column Connections Subjected to Earthquake Loading

摘要

An experimental investigation was performed with the object of evaluating and improving methods of repairing and strengthening of beam-to-column connections damaged by earthquake action. Commonly used repair procedures and strengthening details as well as modifications and improvements of those procedures were tested to compare the behavior of damaged and repaired connection subassemblies with that of undamaged subassemblies. Five subassemblies of single beam-to-column connections and six multiple connection subassemblies each consisting of two exterior and one interior connection, with some including a floor slab, were subjected to twelve cycles of a predefined cyclic displacement routine. The specimens were repaired using repair techniques such as replacement of damaged concrete, enlargement of section, addition of rolled steel elements, etc. The repaired specimens were then subjected to the same loading history as that used in the original test. Specimens strengthened by reinforced concrete and by steel encasement showed increased strength, stiffness, and ductility and exhibited desirable failure mechanisms.