Is Carbon Fiber the Future of Construction Industry?

Published on 16 Jan, 2019

Over the past century, Steel and Aluminum have replaced wood as the primary material for construction projects globally. However in recent years, carbon fiber is being increasingly used to replace steel and aluminum in construction as its low weight and high load bearing capacity make it an ideal material for retro-fitment projects. In this article we have focused on the key factors driving the utilization of carbon fiber and its potential applications in the construction industry.

Carbon fiber is slowly emerging as a popular alternative to steel and aluminum due to its high strength, high stiffness and low weight.

Carbon fiber contains thin filaments of carbon atoms bound together with plastic polymer resin using heat. It is a popular material across various industries due to properties such as high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion. Carbon fiber has an average longitudinal tensile strength of 2000 MPa1, with elastic modulus of 150–200 GPa2 and, on average, is around 2.5 times stiffer than aluminum.

It has a wide range of applications as it can be formed at various densities in limitless shapes and sizes. Carbon fiber is often shaped into tubes fabric, and cloth, and can be custom-made into any number of composite parts and pieces. Due to these factors, carbon fiber is emerging as a popular alternative to steel and aluminum in sectors such as construction, aviation, and automobile.

1Megapascal | 2Gigapascal

The unique properties of carbon fiber make it an ideal material for construction industry.

The construction industry is looking for better alternatives to the materials used currently. This has paved the way for carbon fibers that are increasingly used due to the benefits associated with them. It is a good substitute to steel filaments in fiber-concrete, which are usually cheap cellulose or PAN-based fibers.

Carbon fiber has low thermal conductivity and provides good cohesion when used with concrete, which can be beneficial for high loaded floors and roads. It is also five times stronger than steel, while weighs just one-third of it and has a much higher load bearing capacity. This helps in easy delivery of carbon fiber wraps at the construction location as well as makes installation simpler, which reduces the overall timeline of a project. Carbon fiber can be used as a replacement for asbestos in fiber-cement as it does not create any inhalation issues.

Strengthening is among the major uses of carbon fiber in the construction industry.

Several structural engineering applications utilize carbon fiber-reinforced polymer due to its potential construction-related benefits and cost effectiveness. The usual applications include strengthening structures made of concrete, steel, timber, masonry, and cast iron; retrofitting to increase the load capacity of old structures such as bridges; and enhancing the shear strength and flexural capacity in reinforced concrete structures. Other applications include uses as substitute to steel, in pre-stressing materials and for strengthening cast-iron beams.

For pre-stressed concrete (PC) structures, the repair technology involves the carbon fiber reinforced polymer (CFRP) laminate bonding in which a thin flexible fiber sheet adheres to the concrete surface with a thermos set resin. This increases the shear and flexural capacity of beams and slabs as well as confinement in columns. In case of precast concrete, instead of steel mesh reinforcement, a carbon fiber grid is used in panel faces and as a mechanical link to the outer and inner sections of the concrete wall. This type of carbon fiber grid strengthening reduces the amount of raw materials used as well as the weight.

High cost of carbon fiber is a deterrent to growth.

One of the major challenges impacting the use of carbon fiber in the construction industry, especially in an emerging economy, is the high cost of the material. The cost of carbon fiber is much higher than that of other products such as steel and concrete reinforcement materials. For example, if the average price of steel reinforcement is around USD7–10 per sq. ft., the average cost of carbon fiber installation would vary in the range of USD60–100 per sq. ft.

Apart from the high initial cost, lack of awareness regarding the overall cost advantage and preference for cheaper traditional products such as steel and concrete have hampered the usage of carbon fiber in structural reinforcement projects.

Despite the challenges, utilization of carbon fiber in construction sector is expected to increase.

Factors such as durability, ease of installation and decline in cost are expected to drive the demand for carbon fiber in the construction sector in future. Carbon fibers can be installed easily without modifying the architecture of a structure and can be applied to the surface of any shape. This reduces the overall project timeline by almost 50%, depending on the size of the project, which brings down the cost.

Decrease in cost is expected to boost demand for carbon fibers in the construction sector. In the last decade, the cost of carbon fiber declined from almost USD150 a pound to USD10 a pound. According to some estimates, the cost of carbon fiber may decline by almost 90% in the near future, mainly due to advancement in production techniques and reduction in prices of raw materials. Increasing affordability, coupled with the benefits, is likely to result in the emergence of carbon fiber as a strong replacement for other metals.

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