Prestressed GFRP
Prestressed GFRP
(OP)
Hi All,
I am looking into the use of prestressed GFRP reinforcement for the design of bridge girders (box, NU or AASHTO type). Is anyone familiar with this? I am still determining the layout of the structure but most likely, it will be a single 100' span on 25 deg skew. Any example calculations for the GFRP reinforcement would be great but will also gladly take any suggestions/advice. Thank you.
I am looking into the use of prestressed GFRP reinforcement for the design of bridge girders (box, NU or AASHTO type). Is anyone familiar with this? I am still determining the layout of the structure but most likely, it will be a single 100' span on 25 deg skew. Any example calculations for the GFRP reinforcement would be great but will also gladly take any suggestions/advice. Thank you.





RE: Prestressed GFRP
Memon, A.H. (2003). "Crack control with GFRP bars in steel-free concrete deck slab". Proceedings, Annual Conference - Canadian Society for Civil Engineering , 2003 , p. 906.
Precast concrete decks for slab-on-girder systems: a new approach
Author: Mufti, AA
Cheers,
Shoot for the Moon, even if U miss, U still land among Stars!
RE: Prestressed GFRP
May I ask why the unique choice of using GFRP rebars for girders ? Are there material availability constraints to this project ? Please elaborate.
RE: Prestressed GFRP
It is the preference of the client based on past experience. Material availability is not an issue but the client has not had success with cast-in-place concrete so they prefer everything precast. I believe their biggest reasoning for going in the direction of GFRP instead of steel for reinforcing is due to location and environment (Northern Ontario). The temperature drops to -40 Celsius with lots of snow therefore they use lots of salts for anti-icing. So it is likely durability and maintenance issues that led to this thinking. I have seen a few bridge designs using prestressed GFRP but I have not come across any design guidelines from CSA or ACI.
Shz713, thanks for sharing!
RE: Prestressed GFRP
Thanks for the info. I have come across GFRP rebars being used in bridge decks, but not in girders. I am aware of some studies conducted by NY State DOT on using GFRP. You can find them on their website.
RE: Prestressed GFRP
The only other major lesson learned was that as the GFRP has to be bent when manufactured, and if they are ordered the wrong size or shape it can have a long delay in redelivery of the new bars which can cause issues. Use as many straight lengths as possible, field cutting is possible but field bending is not.
Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries
www.americanconcrete.com