Comparison of concrete and steel structures:

Concrete Structures:

Today, concrete structures are one of the most popular and widely used types of structures in the world, and many famous buildings and structures in the world have concrete structures. Concrete has many advantages in construction and therefore concrete buildings and structures are the major part of structures in today's world. As you know, in these structures, unlike metal structures, in connections, methods such as welding or bolts are not used.

So far, scientists and researchers have written many books and articles about the importance of concrete and its role in construction, and have studied the strengths and weaknesses of concrete structures. To build a concrete structure, concrete and rebar must be used. For this purpose, the rebar of the columns and beams of the structure are woven and then the mold is prepared by pouring concrete.

Advantages of concrete structures:

Concrete structures have several advantages, including:

•        Lower construction and maintenance costs

•        More resistance to moisture (in suitable operating conditions)

•        High resistance to fire and heat

•        Ability to run at different stages

•        Homogeneity of materials

·         Availability and abundance of materials such as reinforced concrete, cement and rebar

•        Requiring less knowledge and expertise in design

•        No need to weld or install bolts

•        More suitable connections of columns and diaphragm to the roof

•        Proper stability and durability of flexural frames

Disadvantages of concrete structures:

•        Needing to spend more time for reinforcing and molding concrete

•        Need for soil laboratories to test concrete

•        Weight gain compared to metal structures

•        Decreased strength and stability of the structure over time

•        Requiring dropped ceiling

•        Applying more pressure during an earthquake due to the heavier weight of the structure

•        Limiting space

•        Wasting more materials

•        The possibility of work being delayed or prolonged in the event of climate change such as rain

Metal Structures:

Today, metals or alloys such as steel are used in the construction of many buildings and structures, especially skyscrapers. Metals are scattered all over the planet, and humans have long learned how to use them. Especially in the road and construction industries. Because the use of metals is very economical due to having a suitable melting point, ability to conduct electric current, ability to weld, use of bolts or riveting, flexibility and other things.

Of course, in metal structures, important points should be considered, such as the type of joints (welding of the structure or installation of bolts), as well as other factors such as the possibility of catching fire or existence moisture. A study has shown that the World Trade Organization's twin towers in New York, which were attacked on September 11, 2001 and caught fire and then collapsed, would had a lower fire intensity if they had a concrete structure instead of a metal one. The fires would be much smaller and more limited, and on the other hand, the people caught in them had a few more hours to escape, in which case the death toll would be much lower. On the other hand, the cost of construction and implementation of steel structures is higher than concrete structures, but instead the speed of work is higher.

Advantages of metal structures:

•        More installation and implementation speed

•        Easier to repair and eliminate possible damage to the structural frame

•        No need for specialized and highly experienced personnel

•        Possibility of creating prefabricated buildings and structures

•        More flexibility of metal than concrete

•        Less weight

•        More resistance to concrete materials over time

•        More efficient use of space

•        More stability and resistance to powerful earthquakes

•        No need for a soil laboratory

•        Ability to use to build sheds and other large or small buildings

•        Easier destruction

•        The initial calculations being closer to reality

•        Ability to change or add new sections after creating floors

•        Less construction time limit during extreme weather changes (snow and rain)

•        Less waste of materials

•        No need for a dropped ceiling

Disadvantages of metal structures:

Compared to steel structures with concrete, steel structures also have disadvantages compared to concrete structures, including:

•        Less resistance of steel to heat and fire

•        More cost

•        Possibility of corrosion of metal because of various factors

•        Need for precision welding or installation of standard bolts and nuts

•        Needing to test the welding and examining how expensive it is

•        The need for careful control and inspection of welding by the supervising engineer

•        The tendency of the steel frame to bend naturally

•        Possibility of rust in wet areas