Strengthening of Columns for Confinement - Strengthening Design of Reinforced Concrete with FRP - page 214

Plot the approximate confined interaction diagram. The experimental near-balanced
point is at P n = 325 kips and M n = 20 0 k-ft.

Problem 7.4
One of the rectangular columns (B03-b) that was tested by Bousias et al. (2004) is
investigated in this problem. The following are the properties of the column, see
Figure 7.P.1:

FIGURE 7.P.1

Height 9.84 in. 250 mm

Width 19.69 in. 500 mm

Clear cover 2 in. 51 m m

r c 0.52 in. 13.21 mm

f c 2.66 ksi 18.35 M Pa

n × t f 5 × 0.005 in. 5 × 0.127 mm

E f 33,350 ksi 230.08 GPa

ε fu 0.015 0.015

f yt 41.47 ksi 286.10 MPa

Tie spacing 7.87 i in. 200 mm

Tie diameter (ϕ = 0.31 i in.) (ϕ = 7.87 m m)

Longitudinal bars

4 (ϕ = 0.71 i in.) 4 ϕ 18.03 m m

f y 81.2 ksi 560.2 MPa

Plot the approximate confined interaction diagram. The tension-controlled experi-
mental point is at P n = 194.625 kips and M n = 90.036 k-ft. Note that bending is about
the y axis (α = 90°).

Problem 7.5
One of the square columns (MS6) that was tested by Memon and Sheikh (2005) is
investigated in this problem. The following are the properties of the column, see
F i g u r e 7. P. 2: