Composite materials are innovative substances created by combining two or more materials with different physical properties to achieve superior performance characteristics.
These remarkable materials are found in a wide range of surprising applications, from ancient mud bricks to modern aerospace engineering.
Some fascinating examples include wood, a natural composite of cellulose fibers and lignin; fiberglass, a combination of plastic and glass fibers; and advanced materials like Kevlar and carbon fiber, which are used in industries such as automotive, sports equipment, and defense.
Other surprising composites include translucent and absorbent concrete, Pykrete (a mixture of ice and wood pulp), composite honeycomb structures, and engineered bamboo.
The versatility and adaptability of composite materials have revolutionized various fields, allowing for the creation of lightweight, strong, and durable products that can be tailored to specific applications, ultimately pushing the boundaries of material science and engineering.
Durability and saving energy are some of the important properties of composites which provide a go-green initiative in the industrial practices. RCC is another major application of composites. In traditional building and erections, slabs transfer the load to beams.
But if the slab is tightly integrated with steel beams, it acts as a composite beam. It is much stronger in manufacture than the traditional beam approach. In this article we shall see composites in construction and manufacturing industry and their applications.
Advantages and uses of Composite Materials in Construction
The use of composites in the construction industry is nothing new, indeed it is dating back over 6000 years.
Some of the earliest records include straw and mud for waffle and daub-type building construction.
The use of composite materials in construction is commonplace. The most globally used composite is concrete formed by amalgamation of aggregate with cementitious matrix.
IN spite of its predominant usage, concrete is the most destructive material on earth because of its tendency to urban heat island effect.
The production of cement contributes to 4-8% of world’s co2 emission, emphasizing the sector’s staggering carbon print.
This led to a move towards replacing or upgrading the traditional construction materials like concrete with modern alternatives that offer properties like weight saving, corrosion resistance, ease of installation etc.
Types of composites in construction and Physical Properties
The remarkable properties of composite structure made their presence in the field of construction.
In recent years there have been numerous high-profile infrastructural projects that have made significant use of laminate composites namely FRP.
Composite Materials Examples
Fiber Reinforced Polymer (FRP)
They typically comprise glass, carbon, aramid or other fibers set in a polymer resin matrix like epoxy resin or polyester. Fiber composite has found its use in the aerospace construction projects.
They offer attractive properties like corrosion resistance, high strength to weight ratio and durability.
FRPs are most commonly used in bridge deckings, cladding panels and in concrete reinforcements.
Jinzan flood mitigation channel in Saudi Arabia has used 11000 km glass fiber reinforced polymer (GFRP) rebar to reinforce a 23 km long concrete channel, one of the world’s largest projects, constructed using composite.
This project is a significant turning point in the use of composites within the infrastructure sector and demonstrates their significant potential as an alternative to steel rebars for concrete reinforcement.
Metal matrix composite (MMCs)
In MMCs carbon or ceramic is embedded in metal matrix like aluminum or titanium. They show properties like improved strength, stiffness and thermal properties.
Specific applications include large span roof systems, special structures for which maintenance is hard to carry out; structures in aggressive environments, structures that are exposed to extremely low temperatures.
Fiber cement composites (FCRs)
FCR has attained a greater monument in the construction industry. The matrix and the mechanism within these composites have resulted in the development of a mix with better fiber-matrix interface.
These developments facilitated by composite production process and the overall continual improvement in their performance have rated FCRs in a higher position.
The matrix is of cement, which itself is a composite formed of several materials. and the second main component is fiber, discontinuous and its orientation is random in nature and is distributed within the volume of the whole composite.
The matrix will be either a mortar or concrete with specified aggregates and additives. Any air voids contained within the matrix is considered as its part.
These composites have high fire resistance, durability and dimensional stability. Commonly used in exterior siding, roofing cladding.
Wood polymer composite (WPC)
WPC is a revolutionary replacement for the wooden home construction products, composed of wood fibers combined with thermoplastics like polypropylene or polyethylene, hence can be termed as wood plastic polymer.
It is a modern and ecological material which is made of 60% pvc, 30% rice and wheat husk, 10% calcium carbonate and additives.
It is the best substitute of plywood because of its strength and durability, it retains the best properties of wood and eliminates all the flaws which are faced by wood.
Its applications are widely seen in fencing, outdoor furniture, partitions, exhibition stands and decking. It gives the false look of wood but has resistance to moisture, pests and decay.
Carbon fiber reinforced polymer(CFRP)
It is composed of carbon fiber embedded in a thermosetting matrix namely polyester resin. It provides high tensile strength, good fatigue resistance and low density.
These are used in structural strengthening applications like in buildings, bridges and other infrastructures.
Concrete composite
These are made by incorporating steel or glass fibers as reinforcing material in concrete matrix.
They enhance the properties like strength, durability and crack resistance. These are found in application of precast elements, tunnels, and high-performance flooring. Reinforced composite make the structure and buildings lighter.
The above are the most commonly used materials in the construction industry. The selection of composite depends on the project requirements including lading, bearing capacity and durability.
Frequently Asked Questions (FAQ)
What composites are used in construction?
They include concrete, reinforced plastics, cement, steel–reinforced concrete, and composite wooden beams. These materials are generally durable and strong.
What are composites in civil structures?
In structural engineering, composite construction exists when two different materials are bound together so strongly that they act together as a single unit from a structural point of view. One common example involves steel beams supporting concrete floor slabs.
Why are composites used in construction?
It contributes to a lower cost of construction, as much less material can be used without sacrificing structural stability. Composites are corrosion resistant, which means that they do not rust or corrode like metal alloys.
Future scope – Fabrication and Advantages of using composite Materials
There are certain challenges faced while using concrete. However, we can overcome some or all by replacing or upgrading traditional material concrete.
Infrastructure projects have different applications for the citizens of the country. Strong and stiff carbon and glass can be used for railway projects.
Composite products are made up of two or more materials with dissimilar chemical or physical properties. The range of properties help the construction applications. They are used in high-performance building projects.
Composites could offer great opportunities for leveling up our global infrastructure. The reinforcement materials are changing and building products need to be less costly and easy to handle. The strength-to-weight ratio should be higher for better service life and economy.
One group doing something in this area is the American Society of Civil Engineers. Their Future World Vision Project envisages what the future cities look like- with floating cities being envisaged by 2040, and smart mega cities in future.
For all these concepts, modern composites seem to offer an ideal solution. We can all agree that precisely what our future cities might look like isn’t 100% clear right now.
What is clear is that composite materials appear to offer potential solutions that closely fit our global infrastructure needs, as well as our anticipated needs of the future.
