how can we increase the fire resistance of steel ? so it can possess more effective role as building component ?! in this report we discuss these subjects .

1. Fire proofing of Steel
Prepared by : Shakar Husain

2. • Structures should be constructed in a manner that it
becomes stable in the occurrence of fire
• Most materials reduce the inherent resistance at the
time of the fire. So to ensure the safe design, this
resistance should be maintained.

3. STRUCTURAL STEEL EXPOSURE TO FIRE
• All the materials reduce their strength when subjected to fire
but steel can recover strength for incombustible nature. When
steel exposes to fire it absorbs thermal energy, after a certain
time of cooling it returns either stable or unstable condition
During this heating and cooling operation the members may be:
• Scrapped due to large deformation.
• Perfect for its straightness behavior after fire exposure.
• Reusable by straightening.

4. Thermal Expansion
• Thermal expansion is the property to indicate the time of heating of the
structure.
• Variation of the thermal expansion is the cause of failure and this effect
is more essential in case of fire. It is the main cause of additional
pressure on connection and it creates sagging of the structure, when
cooling down it tries to return its original stage and creates buckling.

6. Active fire protection
• Active fire protection is the system which is active in the occurrence of fire.
• It is an alarm detecting or a sprinkling system to reduce the effect of fire.
• Its function is to inhibit the small fire or the initiate steps to control the fire before
the action of the fire service.
• In the developing countries the sealed bulb of sprinkler is broken and active the head
of the sprinkler in the meantime of fire action.

8. The Passive Fire Protection Solution :
• Passive fire protection delays the collapse of the
structure through insulating the structural steel
columns and beams that support the building fabric.

9. What are Common Fire Protection Systems for Steel
Structures?
• Boards and blanket fire protection system.
• Intumescent coating steel structure fire protection
system .
• Sprayed cementitious or gypsum based coatings .

10. Rigid Board Fireproofing
• Rigid board fireproofing can be installed quickly and easily.
• One of the benefits is that it can be installed as you go during
the process of installing steel decks and beams.
• This type of fireproofing can be mechanically fastened
• It also is available in different thicknesses to meet
requirements and can withstand moisture and humidity
without losing its fire-stopping characteristics.
• Boards can be designed to precise measurements and can
include decorative finishes.

13. Intumescent Coatings
• Also known as intumescent paint, this method provides fire resistance to structural steel members.
• One of the key benefits is that intumescent coatings will expand as much as 100 times the original
thickness of the material, providing superior fire resistance by creating a buffer between the fire and
the steel members. The coating will undergo a chemical reaction and expand when subjected to
extreme temperatures, but before the temperatures become hot enough to affect the integrity of the
steel.
• Intumescent coatings are a great solution when aesthetics come into play with steel that is exposed to
the general public. The product is applied just like paint, with every layer adding to the overall
thickness of the product. This fireproofing material can be applied to structural wood as well.

14. • This increased thickness would provide fire protection and fire-resistant
ratings is up to 2 hours.
• The thickness of intumescent coating is based on the size of steel
structure elements and it varies from 0.5mm to 5mm.

15. INTUMESCENT APPLICATION OFFSITE

16. APPLICATION OF INTUMESCENT PAIN AT
CONSTRUCTION SITE

17. INTUMESCENT COATING SYSTEM BEFORE EXPOSED TO
FIRE (LEFT SIDE), EXPANSION OF FIRE PROTECTION
SYSTEM AFTER THE STEEL ELEMENT EXPOSED TO FIRE

18. Advantages:
• Low maintenance; comes with excellent bond strength even without a finish coat
• easy to apply, durable, cover complex shapes and design details easily, applied to
steel element surface quickly and can be repaired and maintained easily.
• Does not absorb moisture, thus preventing corrosion. Is even capable of resisting severe
water flow
• Low labor cost
• Low overspray
• Low application time and ease of application makes on-site savings much higher than initial
estimates make apparent

19. Disadvantages:
• high cost, maintenance of good quality coating needs great attention and
effort and it could be damaged if it applied offsite.
• May not be ideal for facilities where impact damage is high
• People often only compare the cost of application against cementitious
coatings and fail to take into account time and material savings

20. Sprayed Cementitious or Gypsum Based Coatings :
• Cement based material or gypsum in combination with lightweight aggregate are
materials used to produce sprayed compendious or gypsum based coatings.
• The cost of this fire protection system is considerably low and provides perfect
fire protection rating of up to 4 hours.
• Added to that, not only it is reliable and efficient but also it can be applied
quickly and is suitable for complex steel members and details of the structure
such as bolts and connections.

21. • However, it does not have sufficient strength to withstand mechanical damages. The
spray application process is wet and messy which might influence the schedule of
the project and its cost.
• Finally, the surface of steel structure should be prepared prior to spray applications,
and great effort would be needed to achieve aesthetically pleasing finishes.

22. SPRAYED CEMENTITIOUS FIRE
PROTECTION SYSTEM

23. APPLICATION OF SPRAY CEMENTITIOUS
FIRE PROTECTION SYSTEM

24. Advantages
• Affordable raw materials and a more economical
solution
• Perfect for dry environments
• Highly resistant to high temperatures

25. Disadvantages
• More field work required and labour cost is higher since the coating
needs to be applied in many layers successively
• Not ideal for places with high moisture levels as it can cause gaps
between the substrate and the cementitious coating
• Prone to spalling, cracking, or disintegration when exposed to vibrations
and heavy impacts
• Adds significant weight to the overall structure which may increase
costs due to increased need for more structural steel.