خلاصة:
This article presents an experimental and numerical study related to the
structural behavior of slender square columns with normal strength concrete
(NSC) strengthened by carbon fiber-reinforced polymer CFRP sheet under a
biaxial bending moment. Twelve specimens of slender RC columns were
tested, which different in terms of effect of the wrapping method by CFRP
sheet in the longitudinal, transverse, and both directions of the column, as
well as the number of CFRP sheet layers one, two, and three layers, have
been studied. In addition, the axial load was applied in the experimental test
with four different eccentricities (0, 20, 35, and 50 mm) to do a comparison
between strengthening and unstrengthening columns under the same of
biaxial eccentrically loads. The columns were then successfully analyzed
with the commercial finite element software using (ABAQUS/CAE 2016).
The numerical study was extended to include some parameters that are
expected to have a significant influence on the behavior of slender concrete
columns, such as compressive strength and the variations in the crosssection
shape has been taken into consideration. The CFRP sheet wrapping
can improve the structural performance of columns by increasing loadbearing
capacity and ductility when compared to unwrapped columns. There
is a good agreement between the experimental and numerical results, and
through that, the theoretical side is relied upon to study the rest of the
variables.
ملخص الجهاز:
Experimental and Theoretical Investigation for Behavior of Reinforced Concrete Slender Column Strengthened By CFRP and Subjected to Biaxial Eccentric Loads Batool W Hassin MSc in Civil Engineering (Structure), University of Kufa, Iraq.
Abstract: This article presents an experimental and numerical study related to the structural behavior of slender square columns with normal strength concrete (NSC) strengthened by carbon fiber-reinforced polymer CFRP sheet under a biaxial bending moment.
2002; Bank 2006; Hollaway and Teng 2008; Rasheed 2014; Eid and Paultre 2017; Pour et al.
In this study, the use of CFRP sheet in the strengthening of slender columns with NSC was investigated, under biaxial eccentrically loads having a different wrapping method by CFRP sheet, the number of CFRP sheet layers, and eccentricity effect.
It was found when the column was confined in the longitudinal direction, the failure occurred at (360 kN) by concrete crush, debonding of CFRP sheet, and flexural crack, and has little deflection compared to the models in this group because the longitudinal fabrics were worked on strengthening in the tension zone and they cannot strengthen the concrete in the compression zone, thus it cannot prevent the premature collapse of concrete.
8. Load-displacement curve at mid- height of column for unstrengthen (به تصویر صفحه رجوع شود) models having the different in eccentricity Figures.
The results of the biaxial compression test of slender square columns show that wrapping CFRP around columns increases both load-bearing capacity ductility and reduces displacement in the same section.