1. This document discusses structural theories and applications of steel as a material. It provides an overview of the physical and mechanical properties of steel, how steel is produced, basic grades of steel, common steel sections, fire protection methods for steel structures, and the form of steel structures. 2. The document includes sections on the brief history of steel production, how steel durability is influenced by exposure conditions and treatment, elasticity properties of steel, measurement systems used to define steel properties, and concludes with advantages and disadvantages of steel structures. 3. References are provided and the document contains tables of contents and figures to illustrate steel properties and structural concepts.

1. AAR 553
STRUCTURAL THEORIES AND APPLICATIONS
STEEL (MATERIAL)
BY :
NAME STUDENT ID
1. INTAN INDAHATI BINTI RAHMAN 2010598037
2. MAISARA BINTI MOHD RAZALI 2010166887
3. NUR AQILAH BINTI MASKURI 2010372209
4. NURUL NAJMI BINTI SALLEH 2010762715
5. WATI ANAK NYAGON 2010167993
LECTURER : MR. SOHAIMI BIN MAN

2. CONTENT
No Topic Page
.
1. Introduction 3
2. Brief History 4
3. Steel 5
4. Steel Durability 7
5. Elasticity 8
6. Basic Grades 10
7. Steel Sections 11
8. Fire Protection 13
9. Form of Steel Structures 15
10. Conclusion 17
11. References 18

3. INTRODUCTION
1. Steel is an alloy made by combining iron and other elements ;
carbon, manganese, chromium, vanadium and tungsten.
2. They act as a hardening agent, preventing dislocations in the iron
atom crystal lattice from sliding past one another.
3. Varying the amount of alloying elements and the form of their
presence in the steel (solute elements, precipitated phase) controls
qualities such as the hardness, ductility, and tensile strength of the
resulting steel.
4. Steel with increased carbon content can be made harder and
stronger than iron, but such steel is also less ductile than iron.

4. BRIEF HISTORY
• Though steel had been produced by various inefficient methods
long before the Renaissance, its use became more common after
more efficient production methods were devised in the 17th
century.
• With the invention of the Bessemer process in the mid-19th
century, steel became an inexpensive mass-produced material.
• Further refinements in the process, such as basic oxygen
steelmaking (BOS), lowered the cost of production while increasing
the quality of the metal.
• Today, steel is one of the most common materials in the
world, with more than 1.3 billion tons produced annually.
• It is a major component in
buildings, infrastructure, tools, ships, automobiles, machines, appli
ances, and weapons.
• Modern steel is generally identified by various grades defined by
assorted standards organizations.

5. Produced from iron ore
by removing the ore’s
naturally occurring
density ρ = 7.7 ÷ 8.1 [kg/dm3] impurities
elastic modulus E=190÷210
[GPa]
Poisson’s ratio ν = 0.27 ÷ 0.30
High strength in
Thermal conductivity κ = 11.2 tension and
÷ 48.3 [W/mK] compression
Thermal expansion α = 9 ÷27
[10-6 / K]
STEEL
Physical properties of
Able to undergo large
steel are related to
deformation without
the physics of the
fracture
material
Ductile material

6. • The alloys and the heat treatment used in
THE MECHANICAL PROPERTIES OF the production of steel result in different
property values and strengths
STEEL CAN BE CONTROL THROUGH :
• Testing must be performed to :
 determine the final properties of
steel
 ensure adherence to the respective
Selection of an standards.
appropriate chemical
composition
MEASUREMENT SYSTEMS USED TO
DEFINE THE PROPERTIES OF GIVEN STEEL.
Processing and
heat treatment
Yield
Toughness is
strength, ductilit
measured by
y and stiffness
Final impact
Hardness is are determined
microstructure testing
determined by using tensile
measuring testing.
resistance to the
penetration of the
surface by a hard
object.

7. STEEL DURABILITY
• Steel structures should be designed to be long lasting and require little
maintenance.
• The durability of steel is influenced by exposure conditions, steel quality and fire
protection.
Steel elements can be exposed to a wide range of conditions
• the atmosphere, soil, seawater, or stored chemicals.
Rusting and surface degradation
• caused by atmospheric conditions should be prevented by anti-corrosion
treatment, such as surface preparation or painting.
Metal coating (galvanizing or zinc spraying)
• provide very good protection giving a rust and surface degradation-free life about
20 years

8. ELASTICITY
A typical curve for steel in tension
The modulus of elasticity for most structural steel tends to be a constant value of approximately
205kN / mm and E=210,000N / mm

10. BASIC GRADES
The four basic grades of steel are :
1. S450
2. S355
3. S275
4. S235
 The numbers represent the minimum tensile strength
of each grade in N/mm.
Grade S275 is the most commonly used in steel
structures at the start of the twenty-first century.

11. STEEL SECTIONS

13. FIRE PROTECTION

14. • The rate of loss of strength is very high at
temperatures more than 300 degree Celsius.
• Commonly used :
 Concrete
 Brick work
 Light encasement

15. FORM OF STEEL STRUCTURE
• Can be constructed or fabricated out of hot rolled
structural steel shapes or cold formed steel sections.
• It provides adaptability, speed, lower monitoring/ or
control; costs and lower preliminaries.
• The effects of environmental and other conditions on the
final shape of a steel building should be discussed by the
design or construction team in the initial stages of
planning the layout and preparing the construction plan.

16. • The architect should consider aspect such as :
1. The integration of facilities
2. Environmental aspects
3. Internal non-commercial values and spaces
4. Creation of a building that would add some excitement, colour, light
and size to provide the visual interest
5. Provision for the easy expansion of the area of the building.
• All steel buildings must comply with the current
building regulations.
• These are statutory instruments approved by
parliament covering all aspects of building
construction.

20. CONCLUSION
ADVANTAGES
• Does not deteriorate with age like timber and concrete
• Steel is very strong and flexible.
• Steel framed houses are ideal in cyclone/hurricane prone regions.
• The best material for bridges and skyscrapers
• Can be recycled.
• Many section types are made (square, tube, H-section, etc).
• Steel is such a versatile material which allows radical architecture.
• Steel has a high expansion rate in changing temperatures, and this must be allowed
for in the engineering.
DISADVANTAGES
• Heavy
• Maintains its strength indefinitely
• Expensive to transport.
• Susceptible to corrosion which steel bridges must be painted continuously,
particularly in a salty environment.
• In conditions of repeated stress and changing temperatures, steel can suffer fatigue
and cracks, and more corrosion and energy intensive needed to produce steel.

21. REFERENCES
• Al-Nageim, H., Durka, F., Morgan, W., and
Williams D., Structural Mechanics:
Loads, Analysis, Materials and Design of
Structural Elements, Great Britain, 2010
• Key To
Metals, http://www.keytometals.com/page.aspx?
ID=SteelProperties&LN=EN
• Parker, B., Prefabricated
House, http://www.localhistory.scit.wlv.ac.uk/arti
cles/DarlastonHouses/Prefabs.htm