About Project
- Vital “Hardened FLEX Equipment Storage Building” must be capable to withstand a Limiting Worst Case Design Basis Event comprising of 360 mph tornado winds, and missiles impact.
- All existing reinforced concrete walls are 24” thick except for one that it was 18” thick.
- The objective of this critical mission was to increase the structures’ bending structural capacity of the 18” wall in order to be able to withstand the loads generated by the 360 mph tornado winds & missile impact with an Engineered Composite Fiber Reinforced Polymer (FRP) System (i.e. Structural Epoxy & Carbon Fiber).
About Project
- Vital “Hardened FLEX Equipment Storage Building” must be capable to withstand a Limiting Worst Case Design Basis Event comprising of 360 mph tornado winds, and missiles impact.
- All existing reinforced concrete walls are 24” thick except for one that it was 18” thick.
- The objective of this critical mission was to increase the structures’ bending structural capacity of the 18” wall in order to be able to withstand the loads generated by the 360 mph tornado winds & missile impact with an Engineered Composite Fiber Reinforced Polymer (FRP) System (i.e. Structural Epoxy & Carbon Fiber).
Services provided
Provided Project Integrator, Project Management, Construction Management including Coating & FRP Inspections, Engineering Consulting.
Input Summary & Requirements
- Concrete compressive strength = 3 ksi
- Density of reinforced concrete = 150 lb/Ft³
- Rebar yield strength = 60 ksi
- Tornado wind load = 360 mph
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Required to withstand horizontal missile 1: 4” x 12” x 12’ wood plank
Missile speed = 300 mph; Missile weight = 180 lbs -
Required to withstand horizontal missile 2: automobile
Missile speed = 17 mph; Missile weight = 4,000 lbs - 18” thick wall’s original bending capacity = 164 kip-in/ft
- The demand bending moment is 540 kip-in/ft for horizontal axis, and 409 kip-in/ft for vertical axis. Final FRP solution (i.e. Epoxy and Carbon Fiber composite system):
Final Engineered CFRP Composite System Solution Conclusion (i.e. Epoxy & Carbon Fiber)
- Upgraded wall’s new design bending capacity = 724 kip-in/ft about the vert & hor directions, after FRP composite system is applied at the wall’s inside face
- Upgraded wall only required two (2) bi-directional plies of FRP composite system to increase the bending capacity to 724 kip-in/ft. Each ply was 0.05” thick.
- Total unit weight of two bi-directional plies = 2.5 lb/yard . Thus, total composite weight is negligible.





