Nov 2019 HOW CARBON CONCRETE IS CHALLENGING REINFORCED CONCRETE ARCHITECTURE
Often referred to as textile concrete, carbon concrete is revolutionising concrete architecture and the way in which civil engineers are reinforcing load bearing constructs around the world. What typically sees the incorporation of steel reinforcing bars (rebar), polymers or alternate composite materials, is now being replaced by new composite material carbon concrete. Incorporating conventional concrete blends with carbon fibres has resulted in an all new, lightweight and sustainable, load bearing concrete with added tensile strength or ductility.
One of the main challenges when reinforcing concrete with steel rods, mesh, wires, or cables embedded into concrete before its cured is its vulnerability to corrosion, especially in the presence of moisture. Given the relative porousness of poorly compacted concrete, exposure to moisture is inevitable and when reinforcing concrete with any type of steel, after ongoing exposure, the steel reinforcement will eventually begin to corrode as a result of ongoing oxidation. Rusting steel will soon lose its strength and its change in dimensional stability and will lead to cracking, compromising the load bearing capacity of what should be a durable and long lasting installation.
Using carbon fibre reinforcements however does not experience such corrosive vulnerabilities together with a number of other benefits that we will list to follow.
- As mentioned above carbon fibre will not rust or corrode, offering a longer lasting strength and reinforcement to loadbearing constructs, high rise buildings, dwellings, freeways, bridges and other installations that need to consistently meet safety standards and regulations.
- The production of carbon fibre concrete produces fewer CO2 emissions compared to other reinforcement materials which translates into a more eco-friendly and sustainable approach to construction and civil engineering.
- While carbon concrete offers a far greater load bearing capacity than any other reinforced concrete materials available, the new composite material is extremely lightweight and far easier to work with than the more weighty steel reinforced installations.
- Carbon concrete composite offers up to six times the loadbearing capacity of all other reinforced concrete alternatives, making this one of the strongest concrete construction materials in the history of Portland cement.
- Carbon fibres are not susceptible to corrosion or rusting due to exposure to wet or humid conditions, instead of having to account for this factor by using thick layers of concrete, less building materials are required to install carbon fibre concrete that will still result in an extremely sturdy installation.
Applied to concrete architecture using three different processes, this corrosion resistant additive can be applied by blending carbon fibres generously distributing the carbon composite throughout the mix resulting in an even and consistent blend. Alternatively carbon fibre composite can be sprayed over the surface or in between layers of poured concrete as exercised by scientists at the Universität Augsburg in Germany. One of the other ways contractors are reinforcing construction sites with carbon fibre is by placing what resembles a fence-like framework made of a carbon fibre grill similar to the steel mesh or wire in-between thin layers of wet concrete.
While the benefits of using carbon fibre concrete as a more efficient method to reinforcing concrete installations are apparent, cost is still a leading deterrent to utilising this state of the art material. However, when taking into account durability and corrosion resistant properties, the cost to install is largely offset against the cost to repair or replace steel reinforced installations that have become compromised over time.