Construction
Effective exterior reinforcement of concrete, timber, and brick structures
Industry
High strength carbon fiber inert to any aggressive media is used to reinforce concrete structures in road and building construction.
Carbon composites have certain advantages which are in a high demand by construction people. The primary advantage is the high strength of carbon fibers and good adhesion of matrix. Those properties provide for effective reinforcement of various structures (concrete, brick, timber).
Advantages of carbon composites
Carbon fiber composites prevail over conventional steel and concrete in construction by all service properties: equally strong, but tens times lighter.
Hardened resin impregnated canvas of just 3 mm in thickness is stronger than 15 mm thick industrial plywood.
- Weight
- High strength
- Resistance to aggressive chemicals
- High specific rigidity
Advantages of carbon fiber composites over steel and reinforced concrete in construction:
75 %
Wall slabs reinforced with carbon fiber mesh are 75% lighter than the same with steel rebars
100 %
Exterior reinforcement of concrete, timber, and brick structures with carbon fiber increases their strength by more than 100%
Carbon fiber versus other materials
| Fiber type |
Tensile strength, MPa | Tensile modulus, GPa | Elongation at break, % | Density, g/cm3 | |
|---|---|---|---|---|---|
| Carbon fiber made of PAN precursor | high strength, standard modulus | 3500-5000 | 200-280 | 1.4-2.0 | 1.75-1.80 |
| high strength, intermediate modulus | 4500-7000 | 280-325 | 1.7-2.1 | 1.73-1.81 | |
| high modulus | 3500-5000 | 325-450 | 0.7-1.4 | 1.75-1.85 | |
| ultra high modulus | 2500-4000 | 450-600 | 0.7-1.0 | 1.85-1.95 | |
| Glass | E-glass | 2500-3800 | 70-75 | 4.5-4.7 | 2.5-2.7 |
| S-glass | 4000-4500 | 80-90 | 5.0-5.3 | 2.5 | |
| Organic | Aramid | 3000-3600 | 60-180 | 2.4-3.6 | 1.45 |
| Polyethylene | 200-3000 | 5-170 | 3-80 | 0.96 | |
| Steel | high strength | 1200-2800 | 200 | 3.5 | 7.8 |
| stainless | 800-2000 | 190 | 3.0 | 7.8 | |
| Basalt | 3000-4800 | 90-110 | 3.0 | 2.6-2.8 | |
| Boron | 3500-4000 | 350-400 | 0.5-0.7 | 2.6 | |
Applications
Carbon composites in construction are most effective for foundation blocks, pillars, power pylons, girders, and bridges. High strength and high tensile carbon fibers reinforce pillars and floor slabs and strengthen bridges.
Fabrics are used as reinforcement for buildings in seismic areas, or neat and virtually unnoticeable bandage for repair and reconstruction of buildings and structures.
Historical background
Carbon fiber was first used for reinforcement of building structures about 40 years ago. Nowadays, you can see thousands of projects using carbon fiber technologies for repair and renovation.
In 1982, carbon tapes were used to strengthen a reinforced concrete bridge in southern Germany (joint project by Sika, Leoba, and designer company Leonhardt, Andrä und Partner). In 2003, this material was used to reinforce girders of a motorway bridge across the Kirzhach river in Russia (104 km on the highway from Moscow to Nizhny Novgorod).
Experience
Carbon fiber reinforced plastic is used for construction of modern buildings, roads, bridges, factories, and for reinforcement of existing structures.
For instance, they built an intricate bridge composed of just two parts 900 kg each in the Swiss part of the Alps. The parts were installed by a helicopter and bolted to each other. A helicopter would not be capable of transporting a similar bridge of steel.
Building elements gain the bonus when reinforced with carbon fiber bars:
Summary
Safety improving and service life extending advanced composite materials have gained widespread currency in civil and industrial construction.
Technologies are evolving, and researchers keep exploring opportunities of using carbon fiber in construction.
Carbon fiber reinforced plastic can reduce the total cost of construction and later maintenance, improve corrosion resistance and extend service life of the structures, address deterioration of pipelines.