Metal corrosion destroys reinforced concrete bearing structures and is one of the key drawbacks of steel rebar. Composite rebar is becoming increasingly more attractive due to its physical and engineering advantages. Adding TUBALL nanotubes (currently the only commercially viable single wall carbon nanotubes produced on industrial scale by OCSiAl) expands the boundaries of technical and performance features of composite materials and makes significant improvements in the modulus of elasticity.
TUBALL nanotubes are increasingly being used as a reinforcing additive for various types of composite materials due to their ability to improve static and dynamic mechanical properties of original materials. Depending on the type of resin, production method, and a number of other parameters, they can significantly improve the characteristics affecting the polymer matrix properties and its adhesion to the fiber. As a result, the material's fatigue strength, creep resistance, bending strength, interlaminar shear strength, damage resistance, impact resistance, as well as a number of other key characteristics, are enhanced.
PolyCompozite LLC, one of the largest manufacturers of composite materials in Russia, is marketing composite rebar reinforced with TUBALL nanotubes. To make composite rebar with a diameter of 5 mm, PolyCompozite added 0.05 wt% of nanotubes using a TUBALL MATRIX concentrate simplifying nanotube handling. The sample test and comparison to the reference part showed tensile strength increase by 32 %, and bending strength increase by 29 %.
| Composite rebar | TUBALL-reinforced composite rebar | |
| Ultimate strength | 1,100 MPa | 1,456 MPa |
| Modulus of elasticity | 51 GPa | 54 GPa |
| Bending strength | 615 MPa |
795 MPa
|
“Over time, such outstanding improvements in
properties will increase the bearing capacity of structures, offer
opportunities to reduce the area of
rebar
,
and allow for real-time monitoring of the protective layer in concrete and at
the rebar location,” said Konstantin Gusev, Head of the Department of Technology
and Quality of PolyCompozite.