Title:
Seismic Behavior of Concrete Columns Confined with Steel and Fiber-Reinforced Polymers
Author(s):
Shamim A. Sheikh and Grace Yau
Publication:
Structural Journal
Volume:
99
Issue:
1
Appears on pages(s):
72-80
Keywords:
column; concrete; ductility; polymer; strength.
DOI:
10.14359/11037
Date:
1/1/2002
Abstract:
Results from an experimental program are presented in which 12 356 mm diameter and 1473 mm long columns were tested under constant axial load and reversed cyclic lateral load that simulated forces from an earthquake. Each specimen consisted of a column cast integrally with a 510 x 760 x 810 mm stub that represented a beam-column joint area or a footing. The test specimens were divided into three groups. The first group consisted of four columns that were conventionally reinforced with longitudinal and spiral steel reinforcement. The second group contained six reinforced concrete columns that were strengthened with carbon fiber-reinforced polymers (CFRP) or glass fiber-reinforced polymers (GFRP) before testing. The last group included two columns that were damaged to a certain extent, repaired with fiber-reinforced polymers (FRP) under axial load, and then tested to failure. The main variables investigated were axial load level, spacing of spirals, thickness, and type of FRP. From the results of the tests, it can be concluded that carbon and GFRP can be used effectively to strengthen deficient columns such that their behavior under simulated earthquake loads matches or exceeds the performance of columns designed according to the seismic provisions of the 1999 ACI Code. The use of FRP significantly enhances strength, ductility, and energy absorption capacity of columns.