Civil engineering is a branch of engineering that is among the oldest and most significant in nature. It lays emphasis on building, designing and maintenance of infrastructure including buildings, bridges, roads, dams, airports and water supply networks. All the structures that sustain the contemporary living are dependent on the expertise and experience of civil engineers. Knowledge about construction materials is one of the most basic concepts of civil engineering. The choice of the right materials also has a direct impact on stability, the durability of the structure, safety, sustainability, and cost.
Materials used to construct buildings have changed a lot. In ancient civilization, natural resources like stone, mud and timber were in use. With the advancement in technology, engineers started employing more high-technology materials like concrete, steel, bricks, glass, and composites. Modern construction projects have been known today to integrate traditional materials with new materials in order to come up with stronger, efficient, and environmentally friendly structures.
In the case of civil engineers, a good knowledge of construction materials is necessary. Engineers should be aware of the physical, chemical properties, benefits, shortcomings and proper usage of every material. Such knowledge assists them to select the appropriate material to be used in every section of a project, which determines their safety and performance over time.
This essay explains the main construction materials that a civil engineer should be familiar with. Most construction works around the globe have been based on these materials. These are concrete, steel, bricks, timber, stone, glass, asphalt, aluminum, plastics and composite materials. Knowledge of such materials helps civil engineers to come up with structures that are powerful, effective, and sustainable.
1. Concrete :
Concrete is one of the simplest and most common building materials that are common in the world. It is a composite material that is composed of cement, water, fine (sand) and coarse (gravel or crushed stone) aggregates. Water is introduced to cement and the chemical process called hydration takes place, which makes the mixture become hard and strengthen after sometime. Concrete is so very versatile, and can be shaped into any shape imaginable before hardening. This is the property that is ideal in the construction of foundations, columns, as well as beams, slabs, bridges, dams, and roads. The concrete is very strong and has a good value of durability and affordability thus being essential in the modern buildings, highways, and infrastructure.
A high compressive strength is one of the principal benefits of the concrete. It is strong enough to support large loads and pressure hence it can be applied in structural work. But concrete is not very strong in the tensile strength and therefore it can crack when under tension. In order to surmount this drawback, engineers frequently reinforced concrete using steel and thereby formed reinforced concrete.
Durability is another feature of concrete. Well constructed and well-maintained concrete buildings can be used over decades. To name a few, concrete made bridges, tunnels and dams can serve over fifty years.
The technology of concrete has developed in the recent years. Different kinds of concrete have been used by engineers such as high-strength concrete, self-compacting concrete, lightweight concrete, and fiber-reinforced concrete. These niche forms enhance performance under various construction circumstances.
The concrete production is however, not environmental friendly since cement production emits a lot of carbon dioxide. This has led to the increased consideration of sustainable options by engineers like green concrete and recycled materials.Concrete is among the most crucial materials in civil engineering despite all these challenges.
2. Steel :
Another crucial building material that is very common in civil engineering works is steel. It is a compound that consists of mostly iron and carbon alloy, other elements are added in low quantity to enhance its strength and durability.
Steel is characterized to have good tensile strength, that is, it is capable of withstanding the force of stretching or pulling. This characteristic renders steel perfect in building structures, reinforcing bars, bridges, high-rise buildings, and industrial buildings.
Reinforcement in concrete is one of the most significant applications of steel in the construction industry. Reinforced concrete is a blend of compressive strength of concrete and tensile strength of steel which gives a material that is effective in handling a variety of loads.
There are also a number of merits of steel over other materials. It is characterized by the high not-to-weight ratio and thus it is able to bear heavy weight but does not need so much material. Steel structures are also built off-site and easily put together on site, lessening construction time.
Flexibility and ductility is also another advantage of steel. Steel work is able to bend under pressure and does not break hence it is able to endure an earthquake and other forces that are dynamic.
Steel can as well be recycled hence it is a friendly material to the environment in as much as it is used wisely. Lots of steel elements that are utilized in the construction can be recycled and reused without compromising on their strength.
There are disadvantages with steel however. It is also liable to corrosion in the presence of moisture and air hence rust and structural corrosion. In order to avoid corrosion, engineers use protective finish, galvanization, or corrosion resistant alloy.
Nevertheless, the challenges have not stopped the use of steel since it is one of the most necessary materials in the modern infrastructure and high-rise buildings.
3. Bricks:
One of the most traditional and old building materials is bricks. They are thousands of years old and have been used in the buildings and infrastructure of the world. Clay is normally used to make bricks whereby the mold is rectangular and is then subjected to a kiln to make them hard and strong.
Walls, pavements, and other architectural structures are usually constructed with the aid of bricks. They are used extensively due to their comparative cost effectiveness, simplicity to operate and a large number of providers.
The second strength of bricks is that they are durable. The brick buildings can survive centuries with less care. There are historical buildings still in existence made of bricks as a testament of their permanence.
Bricks are also good thermal resistant. Structures building using brick walls can have more constant indoor temperatures minimizing the use of energy to heat and cool.
Moreover, bricks cannot withstand fire, and this facilitates their safety in construction than other construction materials.
Nonetheless, brick building takes longer time and requires skilled workers. Another disadvantage of using bricks is that they are not as strong as the reinforced concrete or steel structures and hence can only be used in high-rise buildings.
Other forms of bricks that are typically used under modern construction include clay bricks, fly ash bricks, concrete bricks and engineering bricks. These differences provide enhanced robustness, reliability and longevity.
Nevertheless, bricks still constitute a vital component of construction, especially in residential houses, despite the emergence of other building materials.
4. Timber:
Timber is a natural construction product that is extracted out of trees. Its availability, versatility and aesthetic characteristics have attributed to the thousands of years it has been used in construction.
Timber is typically applied in residential buildings, roofing construction and in flooring, doors, windows, and furniture. It is also commonly applied in temporary buildings like scaffolding and formwork.
Among the key benefits of timber is the fact that it is lightweight. Timber is simpler to transport and work with as compared to concrete and steel. Construction is also adaptable and fast as it is easy to cut, shape, and assemble.
Timber also gives good thermal insulation in that buildings can keep their indoor temperatures at reasonable levels.
The other notable advantage of timber is that it is renewable. Timber can be a green building material when it is obtained in a properly managed forest.
There are however a number of disadvantages of timber. It is prone to fire, insects, molds and moisture. Timber structures have to be maintained and appropriately treated in order to avoid degradation.
Contemporary engineering has given way to laminated timber, cross-laminated timber (CLT) as well as engineered wood products. These materials are stronger and more stable as compared to normal timbers.
Timber is still a good construction material especially when it comes to residential construction and low-rise structures.
5. Stone :
Stone is among the oldest construction materials which human beings used. The pre-historic civilizations employed the use of stone to construct monuments, temples, fortresses, and roads. A great number of these buildings are presently extant.
Stone is a natural material that is found in quarries and molded into constructional material. Construction is done using different forms of stone; granite, limestone, sandstone, marble and slate.
Stone is characterized by great strength, resistance to weathering and durability. It is able to resist severe weather conditions and weight.
Stone is usually applied in foundations, retaining walls, bridges, pavements and ornamental architectural components.
Stone has a long lifespan and this is one of its biggest merits. The stone structures can take centuries before they can deteriorate.
Stone is also very resistant to fire, pests and moisture.
Nevertheless, the use of stone in construction may be costly because it requires quarrying, transportation and high qualification. The stone is also heavy thereby increasing structural loads.
In spite of these problems, stone is still applicable in construction especially in landscape and heritage buildings as well as in architecture.
6. Glass :
Glass is a valuable construction material in contemporary buildings. It is prepared using high temperatures of sand, soda ash and limestone and cooling the heated product into transparent sheets.
Glass is applied extensively in windows, facades, skylights, partitions and decorative applications.
The transparency of glass is one of the key benefits of the material and helps natural lights enter the buildings. This enhances the indoor lighting and eliminates the artificial lighting necessary during the day.
Glass also improves the aesthetic feature of the buildings that make the structure look modern and attractive.
The glass technology of the modern generation has presented numerous kind of glasses such as tempered glass, laminated glass, insulated glass and smart glass.
These new technologies enhance power, safety, energy consumption, and acoustics.
Nevertheless, the glass is not very strong, and it can be ruptured by any impact or pressure. Designing of glass structures should be done by engineers in a way that they are safe.
Glass does not also make a good thermal insulator unless special methods such as the use of special coatings and the use of the double-glazing method.
Irrespective of these drawbacks, glass is very important in modern building and architecture.
7. Asphalt :
Asphalt is a construction material which is mostly utilized in the construction of roads. It is a combination of bitumen and aggregates that include sand, gravel and crushed stone.
Highways, parking lots, and runways on the airports, as well as pavement surfaces, are widely covered with asphalt.
Flexibility is the primary benefit of asphalt. It is not easily broken by its exposure to changes in temperature and traffic loads.
Asphalt also offers a cozy and smooth road surface to drive. It also lowers noise and enhances the performance of the vehicle.
The other advantage of asphalt is that it takes relatively short to construct. Asphalt roads can be opened to road usage soon after construction.
Asphalt however needs frequent repair and resurfacing to ensure that its performance is maintained.
Although these maintenance needs exist, asphalt is used most in the road construction all over the world.
8. Aluminum :
Aluminum is a lightweight metal that is commonly used in the modern construction. It is normally applied in window frames, curtain walls, roofing systems and structural elements.
The low weight of aluminum and its high strength is among the key benefits of the material. This has rendered it applicable in huge structures without causing any excessive load.
Aluminum is also a great corrosion resistant material, and it is suitable in the construction of buildings that are in a hostile environment.
Its other advantage is that it can be recycled. Aluminum can be recycled severally without the loss of its properties such that it is environmentally friendly.
Aluminum is however a costly material compared to others that are traditional. It is also less strong than steel under some structural applications.
In spite of these shortfalls, it can be concluded that aluminum is extensively employed in the contemporary buildings.
9. Plastics and Polymers :
Construction Plastics and polymers are gaining popularity in use in constructions because of their flexibility and durability.
The PVC, polyethylene, and polycarbonate are common plastics that are used in construction.
These are applied in pipes, insulation, flooring, roofing sheets and electrical parts.
Plastics are lightweight, corrosion resistant and they are simple to install. They also offer good insulation qualities.
Nevertheless, plastics are able to decompose at elevated temperatures and UV rays.
In spite of all these problems, plastics are very significant in construction today.
10. Composite Materials:
Composite materials are developed; they are where two or more materials are mixed to obtain better properties.
Some of them are fiber-reinforced polymers (FRP), carbon fiber composites, and glass fiber composites.
Composite materials are strong, lightweight and highly durable.
They are becoming popular in bridges, aerospace structures and complex infrastructure works.
Though composite materials may cost a lot, they can be useful in specialized engineering work due to their performance advantages.
Conclusion
The civil engineering industry depends on construction materials. The construction of any structure highly depends on the materials that are used to make the structure strong, durable, safe, and efficient. To design and construct credible infrastructure, civil engineers should be conversant with the characteristics, benefits, and shortcomings of various materials.
The most significant materials used in the construction today are concrete, steel, bricks, timber, stone, glass, asphalt, aluminum, plastics, and composite materials. All materials possess the peculiar features, which can be used in particular applications.
In contemporary engineering, it is common to blend several materials in order to come up with a more robust, efficient and sustainable structure. Innovations in material science keep on coming up with new materials, which are better in performance and less harmful to the environment.
In the case of civil engineers, it is necessary that they master the knowledge of construction materials. It enables them to come up with structures that are safe, and can withstand environmental factors and serve communities over a number of years.
With technology that is ever changing, the construction materials will also keep on improving, which will determine the future of infrastructure and the built environment.
