Title: Tests of Repaired Reinforced Concrete Columns

Author(s): Jostein Hellensland and Roger Green

Publication: Journal Proceedings

Volume: 69

Issue: 12

Appears on pages(s): 770-774

Keywords: columns (supports);deflection;eccentric loads;failure;reinforced concrete; repairs;static loads;stiffness.

DOI: 10.14359/11284

Date: 12/1/1972

Abstract:
An experimental study was undertaken to determine the load-carrying capacities and deflection properties of repaired concrete columns loaded at constant equal and eccentricities. The columns were rectangular in section and were symmetrically reiforced. The orginal loading history of the columns was complex. It consisted of approximately 4 months of sustained load followed by a period of cyclic load and terminated by short term deformation controlled loading to maximum capacity and beyond. The repaired columns were loaded only with short-term loading to maximum capacity and beyond, again using deformation control. Repair consisted of strightening the columns, chipping out concrete in orginal failure zone, replacing old tires and adding new ties and adding new ties in this zone, then placing new concrete. The load capacities of the repaired columns were found to be 15 to 20 percent less than the orginal load capacities. The repaired columns were considerably "softer" than the orginal columns, with lateral deflections at service load level varying from 1.4 to 3.1 times the orginal deflections at this load level.