Kevlar or better aramid fiber is a class of synthetic fibers with high traction and heat resistance.
Their properties can withstand impact makes it preferable in applications where it is not possible to use carbon or other sensitive components from knocks and bumps.
It is produced with fibers obtained for processing of aromatic polyamides, Kevlar, was patented in 1971 by DuPont.
These fibers are characterized by:
- a high traction resistance similar to that of carbon fibers: 3600 MPa
- low specific weight (which has a higher specific resistance to carbon)
- a high resistance to cutting and impacts (typically used in bulletproof vests)
In building is used as a consolidation of existing structures applied to most masonry and wood to reinforced concrete, due to their elastic modulus is not very high: they guarantee the adhesion of the fibers to the support, or, more rarely, in the form of bars or sections .
The critical points of the aramid fibers are:
- greater absorption of water (which causes, in turn, viscous phenomena)
- greater sensitivity to PH variations and UV radiation