Title:
Reinforced Concrete Jacketing for Masonry Columns with Axial Loads
Author(s):
Y. C. Kog, K. C. G. Ong, C. H. Yu, and A. P. V. Sreekanth
Publication:
Materials Journal
Volume:
98
Issue:
2
Appears on pages(s):
105-115
Keywords:
axial loads; columns; concrete reinforcement; masonry; stirrups
DOI:
10.14359/10194
Date:
3/1/2001
Abstract:
Details of an experimental investigation on jacketing of brick masonry columns is reported in this paper. A tremendous increase in the load-bearing capacity of masonry columns was noted when the columns were strengthened by concrete jackets reinforced with longitudinal steel and stirrups. These columns exhibited a two-stage behavior, one before and another after the cracking of the concrete jacket. The peak load was proportional to the amount of stirrups in the jacket but was not affected by the thickness, grade of concrete, or the amount of longitudinal steel in the jacket. An analytical model of jacketed masonry column reflecting the observed two-stage behavior and the effects of the parameters studied is presented. In the precracking stage, the column is modeled as a composite structure. The postcracking stage is modeled by employing principles of confinement, and the strength gain is estimated using the concept of effectively confined core area developed by previous research on concrete confined by stirrups. A stress-strain relationship for confined masonry in jacketed columns is proposed. Design charts for easy design of reinforced concrete jackets for masonry columns are provided.