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Sustained Load Effects on the Seismic Performance of Concrete Columns.

pdf icon Sustained Load Effects on the Seismic Performance of Concrete Columns. (530 K)
Schultz, A. E.; Welton, S. S.; Rey, L. E.

Earthquake Engineering Research Institute. Earthquake Awareness and Mitigation Across the Nation. U.S. National Conference, Fifth (5th). Proceedings. Volume 2. July 10-14, 1994, Chicago, IL, 589-597 pp, 1994.


earthquakes; columns; concretes; load effects; beams; shrinkage; cracking (fracturing); reinforced concretes; concrete columns


An integrated experimental and analytical research program is undertaken to define the effects of sustained axial load on the seismic performance of reinforced concrete columns. Thirteen beam-column specimens are subjected to simulated seismic lateral loads after the columns sustain axial load for a predefined duration. The experiments are supplemented by computer analyses that simulate 1) redistribution of compression stress during sustained axial load periods, and 2) nonlinear flexural response to short-term lateral loads. Columns which sustained load for longer durations are observed to develop inclined cracks at earlier stages of the lateral load tests, and this damage led to 1) large decreases in lateral stiffness prior to column hinging, 2) modest decreases in peak strength, and 3) marked reductions in energy absorption.