E-glass typically sells for less than $1 per pound as compared for carbon fibers at $8 for standard fiber to $2,000for exceedingly high stiffness fibers. Glass fibers have roughly the same strength as carbon fibers, have about 1/3 the modulus (stiffness of stgandard carbon fibers, but are about 33% more dense. As such an engineer will use carbon fibers when specific strength (strength divided by weight) or stiffness become driving design criteria. That is why carbon fibers have found use is aerospace as most applications are stiffness driven. But look at the storage bins the next time you fly. Most are made from glass as they are made from a sandwich structure, negating the need for high stiffness. Or, I have seen some which use both carbon and glass.
Having said the above, what is weight critical about a bridge column where you are reinforcing concrete, or Gluelam, which is fiber reinforced plywood. Nothing really. But, to take advantage of the strength, the concrete column may break while the wrap is simply stretching as it is not stiff enough to take up the loads. So carbon fibers may have a chance. But my bet is that engineers will figure something out to get it to work thereby significantly reducing the cost. Similarly, beams are stiffness driven and carbon fibers do have an advantage. Again, I go with the engineers being smart enough to make glass work.
Regards
Jake |
