Concrete Structure VS Steel Structure

 Concrete Structure VS Steel Structure

DANIYAL HAIDER (Civil Engineering)

Laureate Folks International

Introduction:

Since the world has been come to in its existence, revolutions, evolutions, and modifications are the major activities that have been observed. According to some Greek scientists, the existence of humans is also an evolution on earth. It’s been more than 2 million years ago that human starts living on this earth's crust. In this long period, humans have immensely revolutionized each aspect of life. Rather it’s their way of living or food or any other facilitations, they have set a standard scale of revolutions or changes. This means that every human has contributed in his whole life span for the sake of revolution and then their progenies continue this cycle, in this way a chain has been built along with we{present us} all are also attached and doing our best for the revolutions. In the present era, we have achieved many milestones which humans 2 million years ago can’t imagine to be held in this world. These revolutions and changes have also affected the construction sector. The mode of living standards becomes more luxurious and comfortable through the modifications.

In the ice age, humans used to live in the caves and facilitate themselves by fire or flame. Then at the end of the ice age, human starts farming and used to live along with the rivers or any other water resources. With the concept of farming, humans have invented the mortar, but that mortar was not like it is like now. Initially, it was a mixture of cow dunk and water. Humans have now replaced the cave with the rock houses, they used clay as a bonding material for rocks. Then gradually they started plastering the rock walls with the dung mortars. According to some studies, they have done this plastering phenomenon because the mortar kept the temperature moderate inside the room. In the same period, some of the wild clans used to live in temporary houses of woods. But as time spends, they also switch to new housing ideas. Along with time, human has discovered bricks, which was widely used. Afterward, concrete was discovered which is formed by limestone. As long as the scientific studies are implemented in real-life, modifications and enhancement also take place in construction. And then finally the discovery of cement takes place in the 19^th century. This discovery turns the construction so feasible and efficient. Nowadays, a structure having tons of weight is sufficiently stable due to this amazing binding material. Concrete has been modified then by the inclusion of cement in it. Moreover, constructions without concrete have also been done like steel structures. Composite constructions have also been introduced i.e.: have embedded steel rods in the concrete blocks namely Reinforced Cement Concrete.

Currently, on a wide scale of construction, concrete structures refer to the composite structure which is mentioned above. While steel structures have only the steel metals for serving as a member. Both structure types are widely used all around the globe with the combination of different classy and modern designs.

 

Objectives:

Motives and goals of collecting facts and theories regarding this specific topic are given below:

·         Relate the construction studies to a common man as simply as possible.

·         Create a distinguishing border between steel and concrete structures.

·         Elaborate on the value of both the structures.

·         Justify whether it is the comparison or suitability of the structure for their selection.

Concrete Structures:

Basically, the structures which possess the coupling or the combination of steel and concrete are the concrete structures. These structures are widely used in Pakistan, especially in housing schemes or residential plans. These structures are constructed gradually and slowly as compared to steel structures. The quality of cement plays a vital role in these structures because cement is the only material that is binding the concrete paste with reinforcement rods.

Types of Concrete Structures:

Plain Concrete Structures: These are the simplest form of concrete structures. It consists of sand aggregate, coarse aggregate, and cement. Which means that they have no reinforcement? Basically, they are not used as a structural member; they are mostly used in pavements and are bad at resisting stress.

Prestressed Concrete Structures: In this type of structure, prestressed concrete is used. Prestressed concrete is a type of concrete which are manufactured off-site. They need to be cast at the site only. The interesting fact about their manufacturing is that they are compressed during their production. The compression is generated by tensioning of high-strength single or multi wires. This process makes the concrete ductile to resist the tensile load.

Smart Concrete Structures: Structures that possess concrete with reinforcement plus fiber as a constituent are called smart concrete structures. The inclusion of fiber makes the concrete strong and resistible against compressional force. Moreover, fiber is useful for preventing cracks in the concrete. This concrete is used in such conditions if there is a dry and harsh environment.

Reinforced Concrete Structures: The composite constructions which have been mentioned above are this one. More than 80% of concrete structures are of this type because these structures have the capability of bearing all kinds of loads with ductile behavior.

Suitability of Concrete Structures:

Plain concretes are brittle and to avoid this property we use a reinforcement bar to make the concrete ductile so that it will cause an increment in its strength. The major weak point of concrete structures is the increment of moisture content. The moisture may be absorbed during rain or maybe from the air. The presence of the excess amount of water can cause a decrease in the compressive strength of concrete because there is less cement and more water in concrete. The water will react with cement and gradually cement content will reach an end but water content is still there. So that water content will evaporate slowly leaving behind pores and these pores are vacant spaces which become the reason of decreasing compressive strength. Moreover, cracking and expansion occur in the concrete due to this reason.

Apart from all of the above, concrete structures are not restricted to use over the above limitations. In most of the countries of Asia, concrete structures are widely used in residential and commercial projects. Most of the Asian countries have alkali soil, which is favorable for concrete structures. Alkali soils can increase the alkalinity of concrete, which is suitable for its durability. This means that the soil is playing a vital role in its suitability. Moreover, the laborers in our country almost know the working phenomena of concrete structures so that’s why it’s become more feasible for a common man to arrange the requirement regarding the construction.  

Steel Structures:

Steel structures have metal components that are joined together forming a sustainable member that can withstand the applied load. No binding material is required in this type of structure. Steel structures are widely used in modern construction. In the few recent years, a rise has been noticed in Pakistan's construction sector regarding the usage of steel structures. These structures do not require a lot of raw materials like concrete structures.

Types of Steel Structures:

Universal Beam: Universal beams are also known as I-beam or H-beam. Their shape and cross-section are like I and H, they are essential members of steel structures. Without the presence of this member, a steel structure can’t be completed. They have great capability of bearing large loads and moments.

Universal Column: like a normal structure, steel structures also consist of beams and columns. The steel columns are called universal columns. They are also available in the I or H shape. These columns are amazing in resisting twists and loads along their vertical axis.

Angled Section: It is basically the steel structures which having L shape cross-section. The angle between the L can be customized according to your need but there are some standards that are widely available in the market. Angle sections are widely used in residential construction, infrastructure, mining, and transport due to their highly ductile behavior.

Suitability of Steel Structures:

Steel structures are somewhat more fabricated and feasible for construction. They didn’t need many laborers as in concrete structures and are 3 to 5 times faster in the aspect of constructing the structure. But somehow it has some major drawbacks too. The most typical issue was again the moisture content. As you all know that water can corrode metals because the oxygen in the water gets oxidized on the surface of metals. This same phenomenon occurs with steel structures and gradually rusting or corrosion will devour the durability of the whole member. But this issue can be resolved by covering the surface of the metal through the coating or layering of non-metal. But this maintenance should be inspected strictly because a minor delay in this maintenance can cause a massive loss. The second most severe issue of steel structures is that they tend to expand under the action of heat. We have a live example of the Eiffel tower, the top part of the tower is increasing 6-7 inches every year in the summer season. This problem can’t be rectified simply.

Conclusion: 

The title of this research seems like it will contain the comparison of concrete and steel structures. But the fact is that there is no fair comparison between these two structures. Because it totally depends on the required conditions of the site. So basically it is their suitability that will require their preference, not the comparison. And it is a fact that everything in this world has its defects and quality. So the defect of concrete structure can’t replace it with the steel one.

 

References:

History Article, written by Becky Little: https://www.history.com/news/humans-evolution-neanderthals-denisovans

A History of Houses, Local Histories, written by Tim Lambert: https://www.sciencedirect.com/topics/materials-science/concrete-structure#

Steel Structure Introduction Article by ATAD Steel Structure Corporation: https://atad.vn/steel-structure-introduction/#

Article by Underwood Steel: https://www.underwoods-steels.co.uk/the-different-types-of-structural-steel-and-their-uses-in-construction