Sustained Load Effects on the Seismic Performance of Concrete Columns.
Sustained Load Effects on the Seismic Performance of
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;
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.