Design of a T-beam - Reinforced Concrete with FRP Bars: Mechanics and Design - page 245

Table 7.2 Beam geometry and reinforcement
Section

Height Width Primary reinforcement Shear reinforcement

Exterior support Four no. 8 No. 4 @ 3 in.

Midspan 28 in. 14 in. Eight no. 8 in two layers No. 4 @ 13 in. (max

spacing)

Interior support Ten No. 8 No. 4 @ 3 in.

Table 7.3 Beam design summary
Limit state

Section Demand/computed Capacity/limit

Ultimate Flexural

strength

Exterior support 145 kip-ft 205 kip-ft

Midspan 271 kip-ft 504 kip-ft

Interior support 349 kip-ft 563 kip-ft

Shear
strength

Interior support 72 kip 80 kip

Serviceability Creep

rupture

Exterior support 6.4 ksi 12.8 ksi

Midspan 12.0 ksi

Interior support 12.5 ksi

Crack width Exterior support 0.016 in. 0.028 in.

Midspan 0.013 in.

Interior support 0.021 in.

Maximum midspan deflection 0.446 in. 1.0 in.

7.3 STEP 1—DEFINE BEAM GEOMETRY
AND CONCRETE PROPERTIES

7.3.1 Geometry
The beam has two spans of length l 1 and l 2 :
l 1 := 30 ft
l 2 := 30 ft
The widths of the two adjacent bays are
l t1 := 17 ft
l t2 := 20 ft
The slab thickness is
t slab := 8 in.
The column width is
b col := 24 in.
A clear top and bottom concrete cover, c c , is
c c := 1.5 in.