Reinforcing a P/T Beam

[Robbiee]

I posted this on the Concrete Post-tensoned Forum also.

A one-span P/T beam supporting the roof of a parking garage needs be reinforced due to the addition of a new point load at about 1/3 of its span. The capacity of the beam was checked and found being exceeded with the new load. What is the best method for reinforcing the beam? And please comment on the use of carbon fiber sheets as a reinforcing material/method.

 

[ishvaaag]

To give better advice complete understanding of the problem would be required. Anyway to maintain the use below likely some applied composite, maybe carbon fiber specialty looks the more promising. Depending again upon the building and use it might be worth to jack up enough (without exerting any substantial force in any beams in floors below, so complete shoring) the beam to make the reinforcement share both the standing and added load.

 

[IDS]

External prestress would also be worth considering.

Fire is an issue with external fibre reinforced polymer systems, which as far as I know doesn't have a satisfactory solution if fire resistance may be required at the same time as the additional load resistance.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/