Design of a one-way slab - Reinforced Concrete with FRP Bars: Mechanics and Design - page 242

The contribution of the FRP reinforcement is:

M n2_ire_FRP := T f2_ire (c u2_ire )⋅(d f2 − c u2_ire )

The total nominal bending moment is:

M n2_fire := M n2_ire_Conc + M n2_ire_FRP = 1.49⋅kip⋅ft

The bending moment under service load at mid-span as computed in Step
3 is:

M s2 = 3.57⋅kip⋅ft

"OK" if MM
"Not good" otherwise

≥

n2_fire s2

Check_Bending Moment_Fire:=

Check_Bending Moment_Fire = “Not good”

The unprotected slab is not adequate to carry the service loads in the
event of a fire for an exposure time of 60 minutes. A solution could be, for
example, to increase the concrete cover to 1.25 inches. In this way, the total
nominal bending moment would also increase to 3.9 kip-ft and exceed the
service demand of 3.57 kip-ft.

REFERENCES

1. H. Jawahery Zadeh and A. Nanni. Reliability analysis of concrete beams inter-
nally reinforced with FRP bars. ACI Structural Journal 110 (6): 1023-1032
(2013).

2. C. E. Ospina and C. E. Bakis. Indirect flexural crack control of concrete
beams and one-way slabs reinforced with FRP bars. Proceedings of the 8th
International Symposium on Fiber Reinforced Polymer Reinforcement for
Concrete Structures, FRPRCS-8, ed. T. C. Triantafillou, University of Patras,
Greece, CD ROM (2007).

3. E. Nigro, G. Cefarelli, A. Bilotta, G. Manfredi, E. Cosenza. Guidelines for flex-
ural resistance of FRP reinforced concrete slabs and beams in fire. Composites
Part B: Engineering , 58: 103-112 (2014).