I have two beams in a ceiling that need reinforcement, and I want to avoid columns, as they are difficult to position. One beam is a glulam beam 115x495 mm with a span of 9.6 m that rests at one end on the other beam, which is a HEA200 with a span of 8.6 m.
I have contacted two different companies that do carbon fiber reinforcement, but from one no response at all, and the other company never seems to have time to look at my project, so I'm considering whether it can be done myself. Unfortunately, I can't calculate this myself, and those who can don't seem to want to...
Is there anyone here who has experience of reinforcing beams with carbon fiber strips on the underside?
According to information I have found, reinforcement with carbon fiber would correspond to reinforcing with an 18 cm steel beam, unclear which type of beam or how it would be installed.
Plan B would otherwise be to reinforce the existing HEA200 with an extra flange and add an extra HEA beam in the middle. An alternative is also to move the existing HEA200 to the middle and replace it with a HEA260, which would be sufficient. But this would be a huge project, so carbon fiber reinforcement would definitely be the best if it works!
I have contacted two different companies that do carbon fiber reinforcement, but from one no response at all, and the other company never seems to have time to look at my project, so I'm considering whether it can be done myself. Unfortunately, I can't calculate this myself, and those who can don't seem to want to...
Is there anyone here who has experience of reinforcing beams with carbon fiber strips on the underside?
According to information I have found, reinforcement with carbon fiber would correspond to reinforcing with an 18 cm steel beam, unclear which type of beam or how it would be installed.
Plan B would otherwise be to reinforce the existing HEA200 with an extra flange and add an extra HEA beam in the middle. An alternative is also to move the existing HEA200 to the middle and replace it with a HEA260, which would be sufficient. But this would be a huge project, so carbon fiber reinforcement would definitely be the best if it works!
Shouldn't be too difficult to do yourself. Check canoe-building forums to see the best way to apply epoxy and carbon fiber. Fiberglass could also be an alternative, requires more material but cheaper.
Know-It-All
· Västra götaland
· 10 971 posts
Shouldn't the carbon fiber strip have some form of prestressing to function?
Smart alek
· östergötland
· 2 809 posts
I have made some racing car parts in carbon fiber, but I don't really understand how this is supposed to work?
Simply adding carbon fiber strips to an existing beam, I can't see how that would be beneficial other than costing money... It's not a miracle material.
In that case, you would have to make a mold and fabricate a reinforcement that is then glued into place.
Simply adding carbon fiber strips to an existing beam, I can't see how that would be beneficial other than costing money... It's not a miracle material.
In that case, you would have to make a mold and fabricate a reinforcement that is then glued into place.
I looked at it, but unfortunately didn't fully understand the program and the answers it provided me...Lulaua said:
From what I could gather, it should work with a strip of "unidirectional carbon fibre" on the underside of the beams, but I'm not completely sure.
A beam that bends is subjected to compression at the top and tensile stress at the bottom of the cross-section. The carbon fiber is intended to reinforce the beam's tensile stiffness on the underside and, in doing so, the whole beam's stiffness. In an HEA beam, it's the flanges that account for (the majority of) the strength and can be reinforced primarily by making these thicker.
I was thinking along similar lines, but isn't there a risk then that the carbon fiber strip will have to take all the tensile stress? I believe that the beams have already sagged due to their own weight and the small load they bear to reach an equilibrium state. Adding the reinforcement in this state might improve the interaction between the beam and the carbon fiber, or am I thinking completely wrong?L Lilllen said:
I can't really offer any advice, but for anyone who might be interested, I can inform you that I measured the sagging lower floor of a double garage in Liljeholmen, Stockholm. During casting sometime in the eighties, either the supervision was lacking, or alcohol was flowing during the reinforcement work and casting. Instead of the 16mm reinforcement that should have been used, the builders had thrown in 10mm and much too little of it. When the entire floor sagged so much that parking cars on the upper level was prohibited, the whole situation was investigated. The underside of the concrete bulged downwards between the pillars so much that it was very clear without measurement that something was wrong. The paint on the ceiling was sanded away in 15cm strips with about 3-meter gaps. Criss-cross. The concrete was wetted with some form of epoxy, and carbon fiber strips were pressed on. These were delivered on a roll. Presumably, they were pre-pregged. The building still stands, and as I understand it, both garage levels are in use today. So the method seems to work.
Carbon fiber is cool, but regardless of the material you use, you need to have the ability to tension the material so it stretches, or prop underneath to create an upward bend while the tension wire is installed; otherwise, you won't get any help unless the deflection increases compared to now. What's above, upstairs or attic?
It shouldn't be too difficult to find out the tensile vs breaking strength of carbon fiber, then you can calculate how much you need to prop up.
Measure the deflection now, and you'll get a good idea of how much weight is on and how much carbon fiber you need.
It shouldn't be too difficult to find out the tensile vs breaking strength of carbon fiber, then you can calculate how much you need to prop up.
Measure the deflection now, and you'll get a good idea of how much weight is on and how much carbon fiber you need.
The glulam beam is the ridge beam and the steel beam supports the two ridge beams. So no attic or upper floor. Currently, it's only the outer roof that loads the beams apart from their own weight. Previously, there were also 7 large skylights (12x16) that have now been removed, and the roof was insulated before. After the reinforcement, it is planned to insulate and install a ceiling, which will increase the load.Gimp said: